Home Medicine Assessment and treatment at a pain clinic: A one-year follow-up of patients with chronic pain
Article Publicly Available

Assessment and treatment at a pain clinic: A one-year follow-up of patients with chronic pain

  • Andrea Hållstam EMAIL logo , Monika Löfgren , Lina Benson , Christer Svensén and Britt-Marie Stålnacke
Published/Copyright: October 1, 2017
Download Article (PDF)
Become an author with De Gruyter Brill
Author Information Explore this Subject
Scandinavian Journal of Pain
From the journal Scandinavian Journal of Pain Volume 17 Issue 1

Abstract

Background and aims

Pain is one of the most common reasons for patients to seek primary health care. Pain relief is likely to be achieved for patients suffering from acute pain, but for individuals with chronic pain it is more likely that the condition will persist. These patients have the option of being referred to specialised pain clinics. However, the complexity surrounding chronic pain patients is not well studied in these settings. This study aimed to describe patients with chronic pain referred to a pain clinic by using the information submitted during their first visit and one year later and also to identify associations between baseline characteristics and improvements in health-related quality of life in the follow-up.

Methods

This was a longitudinal observational study of a sample consisting of 318 patients referred to a pain clinic. One group of patients containing 271 individuals (median age 48, 64% females) was assessed and received conventional pain treatment (CPT group) and a second group of 47 patients (median age 53, 64% females) was assessed by a pain specialist and referred back to their physician with a treatment recommendation (assessment only, AO group). Patient-reported outcome measures in health-related quality of life (EQ-5D), pain intensity (VAS), mental health (HADS), insomnia (ISI), pain-related disability (PDI), kinesiophobia (TSK) and sense of coherence (SOC) were collected at the first visit and one year later.

Results

At baseline, the CPT group reported a low EQ-5D Index (median (md) 0.157) and EQVAS (md 40) as well as considerable high, current pain intensity VAS (md 58), HADS anxiety (md 8), ISI (md 17), PDI (md 36) and TSK (md 39). The AO group showed similar problems (no significant differences compared to the CPT group), except for ISI, where the AO group reported less severe problems. At the one-year follow-up, the CPT group had a statistically significant improvement in EQ-5D, VAS, ISI, PDI and TSK. In the AO group no significant changes were observed. In the CPT group there was an association between a high ISI level at baseline and an improved EQ-5D Index in the follow-up.

Conclusions

The study describes rarely explored groups of patients with chronic pain at a pain clinic. Severe pain problems were present in both groups at their first visit. A statistically significant improvement could be seen in the group that was conventionally treated while this was not the case among those subjects who were assessed and referred. The results imply, that relatively limited treatment strategies were helpful for the patients’ health-related quality of life. Despite these improvements, the patients were not fully recovered, pointing to the chronicity of pain conditions and the need of support for many patients.

Implications

Increased knowledge about assessment, selection and treatment at pain clinics is important to improve the quality of the work performed at these clinics. Despite limited resources, further efforts should be made to collect comparable, valid data on a regular base from pain clinics in order to develop recommendation models.

Keywords: Chronic pain; Pain clinic; Longitudinal observational study; Pain treatment; Insomnia

1 Background

The conventional definition of chronic pain is a state lasting longer than three to six months (or the time needed for the injury to heal). This definition has been modified and now also includes the subject’s experience in relation to dynamic interactions of physiological, psychological and social factors [1]. Neuroimaging studies support the view that chronic pain is a separate identifiable illness [2]. The development of chronic pain is due to several known and unknown factors. One contributing factor is sleep disturbance, which impairs endogenous pain inhibition [3]. Patients who suffer from chronic pain experience a life in a state with not only pain, but often also reduced quality of life and deteriorated mental health, sleep disorders and fatigue as well as sustained disability to perform daily tasks [4,5,6,7,8,9].

Pain relief has always been an important task for health care. Specialised pain clinics were developed after the Second World War based on the anesthesiological tradition of treating pain with nerve blocks and other pharmaceutical treatments. This was mostly successful regarding acute pain, but less apparent for chronic pain conditions [10]. To better cope with this, the bio-medical model was replaced by the bio-psychosocial model [1].

Systematic reviews showed evidence in favour of multidisciplinary/interdisciplinary treatment modalities compared to less comprehensive interventions for chronic musculoskeletal pain to improve quality of life and return to work despite difficulties to improve pain levels [11,12]. Recommendations for patients with other pain aetiologies often focus on pharmacological therapy, with little attention to the bio-psychosocial model or whether patients have their own ideas or desires for treatment [13,14].

In Sweden, primary care is the first line of treatment for patients with chronic pain, followed by the possibility to refer patients to pain clinics or pain rehabilitation units. Research on patients with chronic musculoskeletal pain and their treatment is frequent in the setting of rehabilitation clinics [15,16], but less common when it comes to pain clinics. The bio-psychosocial pain analysis is the first part of the work at the pain clinic and leads to a treatment plan. The pain analysis includes medical history and examination, supplementary investigations and assessment of psychosocial factors such as depression, anxiety or work-related issues [17,18]. Pharmacological therapy is often the basic approach in the treatment at pain clinics. At some clinics, the treatment can be extended to also include physiotherapeutic, educational and psychological treatment as well as invasive interventions.

Although treatment of patients with chronic pain at pain clinics is widespread, there are few studies reported from these settings [6,19,20,21,22,23]. To improve quality of care for patients at pain clinics, more knowledge is needed about the work, the referred patients and the treatment outcome [17,24]. Research in such a clinical context is challenging and needs to be pragmatic. However, it is almost impossible to perform randomised studies. Instead, selecting patients consecutively is a more realistic option.

This study aims to describe patients at a pain clinic, to follow them from their first visit to one year later and to identify associations between baseline characteristics and improved health-related quality of life (HRQoL) in the follow-up. The hypothesis is that there are significant improvements in HRQoL and reduction in pain intensity.

2 Material and methods

2.1 Study design

The study had a prospective and observational design. Patients treated with conventional pain treatment (the CPT group) at the pain clinic were followed from their first visit until one year later. In addition, patients who were referred back to the referring physician after assessment only (the AO group) were followed in the same way. Data were collected from patient questionnaires and medical records.

2.2 Setting

The pain clinic, at Sodersjukhuset in Stockholm, Sweden, has broadened its treatment options in recent decades. Due to the complexity of treatment options, the team included members with different capabilities. The team consisted of physicians specialised in algology, anaesthesia, general medicine or rehabilitation medicine. In addition, there were nurses, a physiotherapist and a psychologist. To meet the patient’s need, the team worked either as individuals, multidisciplinary (different professions loosely collaborating) or as an interdisciplinary team (regular team meetings leading to group decisions for planning, goal establishment and assessment of progress of the patient’s situation).

Patients (≥18 years) were referred to the pain clinic for assessment or treatment from primary care and specialist units. A prerequisite for acceptance at the pain clinic was a complete medical examination and previous initial treatment of the underlying disease. Referrals were assessed by an interdisciplinary team and patients accepted for a visit were invited to a first appointment. This visit included a bio-psychosocial pain analysis and an individualised treatment plan. The treatment plan was then sent to the referring physician for information.

Patients referred for assessment only, identified at the first visit as being in need of minor or suitable interventions at other health care facilities, were referred back to their physician with a treatment plan, forming the AO group of this study. The majority of patients, assessed to benefit from CPT, continued their treatment at the clinic. The patients represented different categories of chronic pain conditions.

2.3 Conventional pain treatment

The CPT was mainly pharmacological, including different drugs appropriate for pain relief and pain-related symptoms such as oral analgesics and adjuvants. Strong opioids were avoided unless there were obvious indications for their use and any risk factors considered. Peripheral nerve or regional sympathetic blocks as well as topical use of lidocaine or capsaicine were also alternative treatments. If single-handed, pharmacological therapy was insufficient, the treatment was extended with interventions from the other team members. Transcutaneous electric nerve stimulation (TENS) [25,26] was used for a wide range of indications in patients who showed motivation for self-treatment. Psychological assessment and individual cognitive behavioural therapy were available for patients with mental distress. To increase understanding and better coping with pain, patients were invited to participate in a pain self-management course of eight sessions, which was based on behavioural medicine principles. Interested patients also had the possibility to participate in an eight-session mindfulness course [27]. The physiotherapist, who was trained in acceptance and commitment therapy (ACT), offered an ACT-inspired course of 6 sessions for women with endometriosis.

The treatment effect was followed up by the responsible health care professionals through patient visits or telephone calls. A major responsibility was also left to the patient, who had to make contact and report treatment results. The length of the treatment period depended on the need, usually ranging from some weeks to about six months. When the patient achieved satisfaction with the pain management, the treatment was continued by the regular physician in primary care. Some patients treated mainly pharmacologically had longer contact with the pain clinic.

2.4 Patients and procedure

The inclusion process is shown in Fig. 1. Participants were recruited from all patients (n = 639) entering the clinic at their first visit between April 2011 and March 2013. Inclusion criteria for the study were pain duration of >3 months, age of ≥18 years. Exclusion criteria were severe illness with expected survival <6 months and cognitive impairment assessed by the Short Portable Mental Status Questionnaire [28]. Of the 406 patients included, 14 individuals dropped out before the follow-up and 10 submitted empty baseline questionnaires. Three months after inclusion, the first author (A.H) reviewed the patients’ records and differentiated the groups based on the actual treatment at that time point. Concurrently, 22 patients were identified as not meeting inclusion or meeting exclusion criteria. Patients included in a multimodal rehabilitation programme (MMR) (n = 42) were described elsewhere [29]. Patients conventionally treated (CPT group, n = 271) and patients assessed by the pain clinic team members, but referred back to the referring physician for further treatment or examination (AO group, n = 47) formed the sample in the current study.

Fig. 1 Flow chart of all patients who came to the clinic during the study period and were screened for inclusion. Patients receiving treatment (CPT group) or where assessed and referred (AO group) are the sample in this study. The multimodal rehabilitation group was described elsewhere [29].
Fig. 1

Flow chart of all patients who came to the clinic during the study period and were screened for inclusion. Patients receiving treatment (CPT group) or where assessed and referred (AO group) are the sample in this study. The multimodal rehabilitation group was described elsewhere [29].

A self-assessment questionnaire was handed out to the patients at their first visit to the pain clinic, when written consent was also obtained (baseline). The questionnaire included seven validated instruments (Table 1) [9,18,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48] for patient-reported outcome measures (PROM), which were described in detail earlier [29]. In addition, questions about pain duration, localisation and education, country of origin and livelihood were identical to those in the questionnaire in the Swedish Quality Registry for Pain Rehabilitation (SQRP) [30]. Age and gender were obtained from medical records. After 12 months the follow-up questionnaires were sent by mail, followed by reminders as necessary.

Table 1

Instruments used for patient-reported measures.

Domain Instrument Abbreviation Description Total score min-max Cut-off for severity levels MCIC References
Health-related quality of life Generic instrument EuroQual Dimension index EQ-5D Index Dimensions: Mobility, self-care, usual activities, pain/discomfort, anxiety/depression -0.594-1 0.1 [31, 32, 33, 34]
EuroQual Visual Analogue Scale EQVAS Levels: no problems = 1, some problems = 2, extreme problems = 3 20 cm vertical scale with endpoints "worst imaginable health state" 0 respectively "best imaginable health state 100" 0-100 [33]
Current pain intensity Visual Analogue Scale VAS 100 mm horizontal visual analogue scale with the endpoints "no pain"to"worst imaginable pain" 0-100 Pain interference with function: ≤34 = mild 35-64 moderate >65 severe 18-19 [18,35,36,45]
Insomnia Insomnia Severity Index ISI Dimensions: sleep onset, sleep maintenance, early morning awaking problems, sleep dissatisfaction, interference ofsleep with daily activity, sleeping problems interfering with quality oflife noticeable by others, distress due to sleep problems during the last two weeks 0-28 No insomnia ≤7 Sub-threshold 8-14 Moderate 15-21 Severe insomnia >22 6-8.4 [9,37,46,48]
Pain-related disability Pain Disability Index PDI Levels: 0= no problems, 4= severe problems Domains: family/home responsibility, recreation, social activities, occupation, sexual behaviour, self-care, life-support activity Likert scales from no disability =0 to svere problems =10 0-70 8.5-9.5 [38,39]
Mental health screening questionnaire Hospital Anxiety and Depression Scale HADS-A Anxiety subscale different statements regarding anxiety, four levels of severity 0-21 No cases of anxiety/depression 0-7 Doubtful cases 8-10 Definite cases 11-21 [40,41]
HADS-D Depression subscale different statements regarding depression, four sevrity levels 0-21
Kinesiophobia Tampa Scale of Kinesiophobia TSK 17 items are assessed on 4-point Likertscales ranging from strongly disagree to strongly agree 17-68 Low kinesiophobia 17-33, mild 34-41, high kinesiophobia 42-68 [43,44]
Pain localisation Number of pain sites NPS Pain localisation in descriptions of 18areas represented at both right and left half of the body 1-36 Local pain: ≤4
Sense of Coherence Sense of Coherence SOC Based on Antonovsky's Sense Of Coherence concept. 13 items to assess an individual's view of life as being comprehensible, manageable and meaningful. Likert scales from 1-7 7-91 Weak SOC ≤ 57 [42,47]
Widespread pain ≥ 5
Moderate 58-74
Strong SOC ≥ 75

MCIC, minimal clinically important change

2.5 Statistics

As all the questionnaires concern patient-reported measures, non-parametric statistics were used. Only instruments with full item responses were included in the analysis. Differences between the two groups were tested using Fisher’s exact test for categorical data and the Mann-Whitney U test for continuous data. To analyse the change between baseline and follow-up, the Wilcoxon sign rank test was used.

To study the association between the independent variables (age, gender, country of origin, education and PROM) and EQ-5D Index increase, logistic regression analysis was performed in the CPT group. The AO group was too small to be analysed by logistic regression analysis. To dichotomize the EQ-5D Index, the minimal clinically important change (MCIC) of 0.1 described earlier was used to differentiate either increased or unchanged/decreased [34]. The independent variables HADS, ISI, and TSK were dichotomized in accordance with previously described cut-off points. EQ VAS, PDI and number of pain sites were categorised related to clinically important states represented in the data. The first and third quartiles were used to categorise SOC. The clinical state which represented best health was used as reference in all outcomes.

Firstly, the univariable association between increased EQ-5D Index and each of the independent variables was studied. Secondly, the statistically significant variables from the first analysis (ISI, PDI and SOC) were entered into a multivariable model together with age and gender. We report odds ratios (OR) and corresponding 95% confidence intervals. To measure the model fit, a Hosmer and Lemeshow test was performed.

In order to investigate possible bias due to missing data, we compared the baseline values of the questionnaires (EQ-5D, VAS, HADS, ISI, PDI, TSK and SOC) between the responders with valid values at baseline and follow-up and the dropouts with missing values at follow-up. We also compared the two groups (CPT and AO) concerning the demographic variables (age, gender, education and country of origin).

SPSS version 22 software was used for data analysis. P-values ≤ 0.05 (two-sided) were considered to be significant.

3 Results

3.1 Baseline assessments

The patients showed complex and heterogeneous pain categories. Mixed pain conditions were represented in 24% (n = 73). Solely neuropathic pain was found in 29% (n = 88), nociceptive pain in 16% (n = 50), visceral pain in 13% (n = 40) or other aetiology 18% (n = 56). In 11 patients no information about the pain condition was available. The demographics, pain duration and localisation are presented in Table 2. In both groups the majority of patients were female (64% in both groups). The majority were middle-aged (31-65 yrs) with 69% in the CPT group and 72% in the AO group, respectively. The young patients (18-30 yrs) were represented in 12% versus 9%, respectively while 19% were pensioner (≥66 yrs) in both groups. In general, the patients showed a long history of pain, with pain duration of >2 years found in 67% in the CPT group and 57% in the AO group, respectively. Employment income was reported by 46% of patients in the CPT group while the proportion was 35% in the AO group (Table 2).

Table 2

Demographic data and pain characteristics at baseline in the conventional treatment group (CPT group) and the assessment group (AO group).

CPT group AO group P-value
Gender Female 173 (64) 30 (64) 1
Male 98 (36) 17 (36)
Age Median (q1-q3) 48 (37-62) 53 (44-63) 0.156
Country of origin Sweden 221 (83) 42 (91) 0.467
Europe 20 (8) 2 (4)
Outside Europe 27 (10) 2 (4)
Missing 3 1
Education Elementary school 39 (15) 9 (21) 0.405
Secondary school/vocational training 117 (44) 22 (50)
University 102 (38) 13 (30)
Other 8 (3) 0
Missing 5 3
Family status Living alone 80 (31) 16 (37) 0.690
Living with family/children 73 (29) 13 (30)
Living with spouse/partner 87 (34) 13 (30)
Other 17 (6) 1 (3)
Missing 14 4
Livelihood Employment income only 80 (32) 14 (33) 0.11
Employment income and sickness benefits 36 (14) 1 (2)
Sickness benefits only 70 (28) 16 (38)
Sickness benefits and/or other allowances[a] 68 (27) 11 (26)
Missing 17 5
Pain duration ≤6 months 25 (10) 5 (18) 0.342
7-24 months 59 (23) 7 (25)
≥25 months 168 (67) 16 (57)
Missing 19 19
Number of pain sites Median (q1-q3) 7 (4-12) 6 (4-12) 0.410
Localisation of worst pain Head and face 8 (4) 4 (10)
Neck, shoulder, arm 41 (20) 3 (8)
Thorax 10 (5) 2 (5)
Abdomen 28 (13) 1 (3)
Sexual organs and groin 12 (6) 2 (5)
Back, upperand lower 41 (20) 12 (31)
Hip and buttock 10 (5) 2 (5)
Leg 39 (19) 9 (23)
Worst area varies 21 (10) 4 (10)
Missing 61 8

  1. Categorical variables presented with n (%) and tested with Fisher's exact test and continuous variables presented with median (q1-q3) and tested with Mann-Whitney U test

Widespread pain was common, as pain localisation ≥6 areas (median) were found in both groups. Located pain on one site was only found in 8% in the CPT group and in 13% in the AO group. The most common pain localizations in the CPT group were shoulder/arm (20%), back (upper and lower, 20%) leg (19%) and abdomen (13%). In the AO group, upper and lower back pain (31%), pain in head and face (10%) and pain in leg (23%) were most frequent. The groups showed no statistically significant differences in baseline characteristics of demographics, pain duration or localisation.

In Table 3, the patient-reported outcome measures at baseline are presented. The CPT group showed higher insomnia than the AO group, otherwise there were no statistical significant differences in the patient-reported measures. No differences were found between genders at baseline apart from TSK, where males presented higher kinesiophobia.

Table 3

Baseline values of PROM in the conventional treatment group (CPT group) and the assessment group (AO group).

CPT group AO group P-value
n md q1-q3 n md q1-q3
EQ-5D Index 249 0.157 0.030-0.673 42 0.159 0.030-0.666 0.585
EQVAS 225 40 30-61 40 50 23-74 0.489
VAS current pain 260 58 31-72 46 38 17-75 0.082
HADS anxiety 257 8 5-11 46 6 3-11 0.152
HADS depression 261 7 4- 11 44 6 2-10 0.207
ISI 255 17 12-21 47 13 9-19 0.020
PDI 239 36 26-47 41 35 23-42 0.319
TSK 241 39 33-46 42 37 31-43 0.209
SOC 237 59 49-69 40 60 52-72 0.709

Presented with median (q1-q3) and tested with Mann-Whitney U test. EQ-5D Index, EuroQol-5 Dimensions Index; EQVAS, EuroQol Visual Analogue Scale; VAS, Visual Analogue Scale; HADS, Hospital Anxiety and Depression Scale; ISI, Insomnia Severity Index; PDI, Pain Disability Index; TSK, Tampa Scale of Kinesiophobia; SOC, Sense of Coherence scale

The CPT group represented patients with complex pain problems since 37% reported severe current pain (VAS ≥65), which was associated with mild to severe anxiety (HADS-A ≥8) in 52%, mild to severe depression (HADS-D ≥8) in 47%, moderate insomnia (ISI 15-21) in 41% and severe insomnia (ISI ≥22) in 24%, as well as high disability (PDI ≥41) in 39% and high kinesiophobia (TSK ≥42) in 39%. The problems were similar in the AO group: 33% reported severe current pain, mild to severe anxiety in 46%, mild to severe depression in 39%, moderate insomnia in 28% severe insomnia in 17%, high disability in 32% and high kinesiophobia in 31%.

When reviewing the CPT group patients’ records, three months after inclusion, the observed treatment was recorded. Medications started and prescribed at the pain clinic were described or 169 patients. The drugs mainly prescribed at the pain clinic were: antidepressants (TCA/SNRI) (n = 123), antiepileptics (n = 36), strong opioids, including tapentadol (n = 35), tramadol (n = 7), paracetamol (n = 8), NSAID (n = 4) and topical administered pharmaceuticals (n = 17), and 5 patients were treated with regional blocks or local anaesthetics. The following interventions were also observed; 105 patients tested TENS and received instructions about self-care with the TENS equipment at home, 25 had individual psychological interventions, 20 participated in the pain management course, 8 in ACT-inspired groups, 5 in the mindfulness course and 6 were prescribed physical activity or recommended physiotherapy and 2 were referred for dorsal column stimulation.

3.2 Changes over time

Patient-reported outcome measures from patients answering both the baseline and the follow-up questionnaire are presented in Table 4. The CPT group showed statistically significant improvements in EQ-5D Index, EQVAS, VAS, ISI, PDI and TSK. The AO group showed no significant changes. The response rate for the follow-up differed between the instruments. In the CPT group the response rate in all instruments was 62% (range from EQVAS 52% to HADS 68%). In the AO-group the response rate for all instruments was 56% (range from PDI 49% to VAS current pain 63%). The dropout analysis of responders at baseline and follow-up compared to responders representing only baseline data (demographics and PROM) of the whole sample showed no significant differences except age. The dropouts were younger than the patients answering both questionnaires.

Table 4

Changes in PROM from baseline to one year later.

CPT group
Baseline Follow up
n md q1-q3 md q1-q3 P-value[a] cs
EQ-5D Index 175 0.157 0.088-0.656 0.620 0.088-0.72 0.000 +
EQVAS 140 40 30-60 49 30-70 0.024
VAS current pain 185 57 30-73 48 21-69 0.002
HADS anxiety 175 7 4-11 7 4-11 0.401
HADS depression 184 7 4-10 7 3-11 0.814
ISI summa 176 16 12-21 15 9-20 0.001
PDI 158 36 25-46 32 18-43 0.000
TSK 156 38 33-46 35 30-43 0.000
SOC 163 59 50-69 60 50-70 0.951
AO group
Baseline Follow up
n md q1-q3 md q1-q3 P-value
EQ-5D Index 28 0.173 0.088-0.656 0.328 0.002-0.691 0.429
EQVAS 25 60 27-71 50 29-72 0.940
VAS current pain 30 35 17-75 47 20-65 0.566
HADS anxiety 29 6 3-11 4 2-10 0.415
HADS depression 26 5 2-8 6 3-11 0.357
ISI summa 30 14 8-20 13 9-19 0.591
PDI 23 35 21-42 32 22-44 0.721
TSK 24 39 31-48 35 29-54 1.000
SOC 25 61 50-74 63 52-72 0.843

Only patients with values at both baseline and the one-year follow-up are presented

3.3 Associations for the improvement of patient-reported measures

Associations with an increased EQ-5D Index in the follow-up were found in the CPT group for patients with low EQ-5D Index, severe insomnia, high disability or moderate SOC at baseline in the crude model (Table 5). In the multivariable model, only ISI remained statistically significant. A Hosmer and Lemeshow test showed good adaption for the model (P-value 0.825).

Table 5

Associations between increment in EQ-5D Index and baseline variables in the CPT group.

n, Total/(% with increment in EQ-5D Index*) Univariable model Multivariable model
OR 95% CI P-value OR 95% CI P-value
Age 41-65 yrs vs ≤ 40 yrs 91 (40)/41 (44) 0.8 0.4-1.8 0.639 0.6 0.3-1.5 0.308
≥66 yrs vs ≤ 40 yrs 43 (42)/41 (44) 0.9 0.39-2.2 0.850 1.3 0.6-2.6 0.675
Gender Female vs male 110 (45)/65 (35) 1.5 0.8-2.8 0.235
Country oforigin Abroad vs Sweden 30 (50)/143 (39) 1.6 0.7-3.4 0.275
Education Primary/secondary school vs university 106 (41)/66 (42) 0.9 0.5-1.7 0.810
EQ-5D Index <0.3 (low) vs = 0.31 (high) 113 (56)/62 (15) 7.4 3.3-16.5 <0.001
EQVAS ≤32 (low) vs ≥ 33 (high) 51 (35)/93 (43) 0.7 0.4-1.5 0.367
VAS current pain ≥65 (severe) vs ≤ 64 (mild/moderate) 63 (41)/105 (40) 1.1 0.6-1.99 0.871
ISI ≥ 22 (severe) vs ≤ 21 (No problems/sub-threshold/moderate) 39 (56)/127 (35) 2.4 1.1-4.9 0.021 3.5 1.3-9.2 0.013
PDI ≥41 (high) vs ≤ 40 (low) 59 (53)/97 (36) 1.96 1.01-3.8 0.045 1.7 0.8-3.96 0.198
HADS anxiety ≥11 (definite cases) vs ≥ 10 (no/doubtful cases) 43 (37)/123 (42) 0.8 0.4-1.7 0.561
HADS depression ≥11 (definite cases) vs ≤ 10 (no/doubtful cases) 38 (37)/133 (41) 0.8 0.4-1.7 0.617
TSK ≥42 (high) vs ≤ 41 (low/mild) 58 (43)/99 (37) 1.3 0.7-2.5 0.479
NPS General ≥ 5 pain sites vs local ≥ 4 pain sites 115 (40)/60 (43.3) 0.9 0.5-1.6 0.671
SOC ≤49 (weak) vs ≥ 70 (high) 32 (19)/40 (14) 2.1 0.7-5.8 0.168 0.8 0.2-3.3 0.796
50-69 (moderate) vs ≥ 70 (high) 84 (67)/40 (14) 3.6 1.5-8.5 0.003 2.2 0.8-5.8 0.115

Analysis performed with logistic regression analyses. * Increment in EQ-5D Index >0.1 difference between baseline and 1year follow-up. OR: odds ratio; CI: confidence interval; EQ-5D Index: EuroQol-5 Dimensions Index; EQVAS: EuroQolVisual Analogue Scale; VAS: VisualAnalogue Scale; ISI: Insomnia Severity Index; PDI: Pain Disability Index; HADS: Hospital Anxiety and Depression Scale; TSK: Tampa Scale ofKinesiophobia; NP: Number ofPain sites; SOC: Sense ofCoherence scale

4 Discussion

The main findings were that the CPT group showed substantial suffering from pain and related problems at baseline, but there was a statistically significant improvement in several outcome measures at the follow-up. Severe sleep disturbance was associated with a greater likelihood of showing improvement in health-related quality oflife (HRQoL) at follow-up than if patients suffered from minor sleep disturbances. Patients in the AO group had similar characteristics at baseline, but did not show any significant changes at follow-up.

4.1 Baseline and follow-up PROM in CPT and AO group

Patients in both groups had low HRQoL (EQ-5D Index median 0.15) at their first visit, indicating deteriorated quality of life compared to subjects with other pain conditions. For comparison, patients in primary care with mixed chronic musculoskeletal pain reported an EQ-5D Index of 0.7 [49], patients with neuropathic pain an EQ-5D Index of 0.47 [50] and patients in a specialised rehabilitation programme 0.25 [7]. In a Swedish survey study, the EQ-5D Index in the normal population was found to range between 0.7 and 0.9, depending on age; individuals with different disease problems ranged between 0.66 and 0.79 [51]. In our follow-up, the CPT group improved in the EQ-5D Index (0.47 points) and reached the levels of the population with diseases [50]. By comparison, patients with chronic pain in our previous study who were treated with the more extensive MMR, improved in EQ-5D Index 0.5 points [29]. Similar findings from the SQRPR were reported from 152 patients from a rehabilitation unit in Stockholm [52], with improvement in EQ-5D Index of 0.47 points. These figures show that the acquired improvement is in line with other results and reflect possible outcomes by today’s resources and available interventions.

In the CPT-group, 37% reported severe current pain (VAS ≥65) intensity at baseline. In the follow-up, the VAS median value had improved from VAS 57 to VAS 48 (Table 4a, P<0.002). Other studies of patients with muskuloskeletal pain have shown varying results regarding improvements in pain intensity. In a one-year follow-up of a specialised rehabilitation programme, the improvement was 13 points on VAS [53], in a six-month follow-up at a multidisciplinary pain clinic VAS changed by 15 points [19]. These examples of different follow-up periods and settings illustrate some difficulties in making conclusions.

Comorbidity of depression and anxiety are common in patients with chronic pain [7,53]. In our sample, an HADS-anxiety level indicating doubtful cases of anxiety (median 8), was found in the CPT-group at baseline. The subgroup of patients answering baseline and follow-up questionnaires scored below the level of probable anxiety at baseline. The HADS -depression median value was below the cut off for depression. These levels are surprisingly low, but might be related to the selection of patients for the treatment alternatives in the actual study. Patients with complex pain conditions with more severe comorbidity were selected for an MMR and thus not included in the study, but described earlier [29]. These findings support the fact that the clinical selection process is working well.

Moderate insomnia was found at baseline in the CPT-group, comparable to sleeping disorders reported in 50-65% of patients with chronic back pain [8] or in patients participating in chronic pain rehabilitation programmes [7,9]. In our follow up, statistically significant improvement in ISI was observed comparable to the study by Wilson et al. [9]. The disability rating in our sample at baseline (PDI median 36) was in accordance with PDI reported in patients with musculoskeletal pain and pain related to spinal disorders [54]. In the follow-up, PDI decreased significantly. Few studies use PDI as an outcome measure. However, in a study where a one year follow-up of patients participating in MMR was done, PDI improved after three months after which it returned to base line [55].

In spite of improvements, our patients still reported high levels of pain, insomnia and disability in the follow-up compared to the normal population. The remaining HRQoL level was still comparable to those of individuals with chronic diseases.

4.2 Analysis of associations

Insomnia was found to be the only factor which was associated with an improved EQ-5D Index at follow-up. There might be several explanations for this: sleeping disorders were assessed as one problem where the pharmacological treatment (high proportion of antidepressants and gabapentinoids) was appropriate to treat pain and insomnia. Furthermore, also psychological or educational interventions covered efforts to improve insomnia. Since previous studies have shown a clear relationship between insomnia and chronic pain [3,7,8], it seems obvious that improved insomnia may also affect the consequences of chronic pain as quality of life. In clinical practice, assessment and follow up of insomnia seems to be of importance when evaluating treatment results.

4.3 Strengths and limitations

This is a pragmatic study in a clinical context which is one of few attempts to describe patients and treatment outcome at a pain clinic [6,19,20,21,22,23]. Several difficulties have to be mentioned. Currently, few pain clinics report structured evaluation programmes in Sweden. The organisation of pain clinics differs greatly, and there is no agreement on which outcome instruments should be used. Furthermore, well-structured and valid studies are needed to explore, evaluate and compare. In the present clinical context, randomisation was not possible, since the treatment alternatives were decided individually and according to patient’s need.

As we have sought to describe the complexity of chronic pain, a wide range of instruments was used. Our results are based on established statistical methods as significance. Another perspective is to value the results by using minimal clinical changes. However, this perspective has some problems. There are MCIC described for chronic pain in four out ofthe seven instruments used in the present study, and discussions about MCIC are ongoing in several [9,46,56].

The strengths of the study are its sample size, including all eligible patients during a two-year period and the use of a battery of PROM. The choice of instruments for assessing HRQoL and symptoms is crucial for clinical studies and an issue to be discussed continuously [50,57,58]. We used EQ-5D Index as our main outcome measure, meeting the needs for a validated, instrument used in research and in clinical settings, with the benefit of few items for the patient to respond to. Several other well validated instruments were chosen to monitor important outcome domains or factors which were assumed to be predictive.

The one-year follow-up response rate of all instruments was found in 62% (CPT group) and 56% (AO group), in line with or better than other findings in patients with chronic pain [21,23]. For ethical reasons and for a better response rate, as few items as possible are desirable. Efforts to find short versions of validated instruments are encouraged for future research, for instance to measure insomnia [59]. Another way to improve response rates and routines is to connect pain clinics to a national quality register.

The study does not allow conclusions about what kind of intervention is most successful, as the sample included different pain aetiologies, treatment alternatives and lengths of treatments. Patient’s compliance with all kinds ofinitiated interventions is challenging and needs further research [19,21].

Bearing in mind the limited size of the AO group, the results must be interpreted with caution. It was not our objective to have them as a control, as done by Becker et al. [19]. Few studies have explored the significance of assessment by pain specialists [19,53,60]. More research is needed to study whether the recommended treatment was eligible and possible to implement by the referring physician.

5 Conclusions

The study describes rarely explored groups of patients with chronic pain at a pain clinic. Severe pain problems were present in both groups at their first visit. Statistically significant improvement could be seen in the group that was conventionally treated while this was not the case among those subjects who were assessed and referred. The results imply, that relatively limited treatment strategies were helpful for the patients’ health-related quality of life. Despite these improvements, the patients were not fully recovered, pointing to the chronicity of pain conditions and the need of support for many patients.

Highlights

  • This is a longitudinal observational study of patients at a pain clinic.

  • Considerable pain and low health-related quality of life were reported at baseline.

  • Patients treated at the pain clinic showed improvements at the one-year follow-up.

  • Pain clinics need to collect comparable, valid data on a regular base to improve care.

Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, and Unit of Anaesthesiology and Intensive Care, Sjukhusbacken 10, 118 83 Södersjukhuset, Stockholm, Sweden

  1. Implications: Increased knowledge of patients referred to, assessed and treated at pain clinics is important in order to improve the quality of the work done at these clinics. Despite limited resources, further efforts should be made to systematically collect information from pain clinics in order to develop recommendation models.

  2. Ethical considerations: The study was approved by the Regional Ethical Review Board, Stockholm (Dnr: 2010/1903-31/5) with a supplementary application (Dnr: 2012/75-32). Patients were given oral and written information about the study and written consent was obtained from the participants before inclusion.

  3. Conflict of interest

    Conflict of interest statement: The authors have no conflict of interest.

Acknowledgments

The authors wish to thank Stiftelsen Tornspiran and the Department of Anaesthesia and Intensive Care at Sodersjukhuset for support.

References

[1] Gatchel RJ, Peng YB, Peters ML, Fuchs PN, Turk D. The biopsychosocial approach to chronic pain: scientific advances and future directions. Psychol Bull 2007;133:581–624.Search in Google Scholar

[2] Tracey I, Bushnell MC. How neuroimaging studies have challenged us to rethink: is chronic painadisease? J Pain 2009;10:1113–20.Search in Google Scholar

[3] Finan PH, Goodin BR, Smith MT. The association of sleep and pain: an update and a path forward. J Pain 2013;14:1539–52.Search in Google Scholar

[4] Johannes CB, Le TK, Zhou X, Johnston J, Dworkin R. The prevalence of chronic pain in United States adults: results of an internet-based survey. J Pain 2010;11:1230–9.Search in Google Scholar

[5] Breivik H, Collett B, Ventafridda V, Cohen R, Gallacher D. Survey of chronic pain in Europe: prevalence, impact on daily life, and treatment. Eur J Pain 2006;10:287–333.Search in Google Scholar

[6] Fredheim OM, Kaasa S, Fayers P, Saltnes T, Jordhoy M, Borchgrevink PC. Chronic non-malignant pain patients report as poor health-related quality of life as palliative cancer patients. ActaAnaesthesiol Scand 2008;52:43–8.Search in Google Scholar

[7] Alfoldi P, Wiklund T, Gerdle B. Comorbid insomnia in patients with chronic pain: a study based on the Swedish quality registry for pain rehabilitation (SQRP). Disabil Rehabil 2014;36:1661–9.Search in Google Scholar

[8] Tang NK, Wright KJ, Salkovskis PM. Prevalence and correlates ofclinical insomnia co-occurring with chronic back pain. J Sleep Res 2007;16:85–95.Search in Google Scholar

[9] Wilson KG, Kowal J, Ferguson EJ. Clinically important change in insomnia severity after chronic pain rehabilitation. Clin J Pain 2015, http://dx.doi.org/10.1097/AJP.0000000000000325.Search in Google Scholar

[10] Gerbershagen HU. [Pain treatment yesterday - development of organized pain management]. Anasthesiol Intensivmed Notfallmed Schmerzther 2003;38:303–11.Search in Google Scholar

[11] Scascighini L, Toma V, Dober-Spielmann S, Sprott H. Multidisciplinary treatment for chronic pain: a systematic review of interventions and outcomes. Rheumatology (Oxford) 2008;47:670–8.Search in Google Scholar

[12] SBU. [Rehabilitation of patients with chronic pain conditions.A systematic review.Report No 198]. Stockholm: SBU, The SwedishCouncil on Health Technology Assessment; 2010.Search in Google Scholar

[13] Scholten PM, Harden RN. Assessing and treating patient swith neuropathic pain. PM R 2015;7:S257-69.Search in Google Scholar

[14] Lofgren M, Norrbrink C. But I know what works - patients’ experience of spinal cord injury neuropathic pain management. Disabil Rehabil 2012;34: 2139-47.Search in Google Scholar

[15] Merrick D [Doctoral thesis] A follow-up of patients with chronic musculoskeletal pain, focusing on multimodal rehabilitation. Umea, Sweden: Umea university; 2012. ISBN: 978-91-7459-425-6.Search in Google Scholar

[16] Nyberg V (Doctoral thesis) Pain rehabilitation in Sweden: a quality registry study. Umea, Sweden: Department of Community Medicine and Rehabilitation, Rehabilitation Medicine, UmeaUniversity; 2011. ISBN: 978-91-7459-210-8.Search in Google Scholar

[17] SBU. [Methods oftreating chronic pain.Asystematic review. Report No177/1]. Stockholm: SBU - The Swedish Council on Health Technology Assessment; 2006.Search in Google Scholar

[18] Breivik H, Borchgrevink PC, Allen SM, Rosseland LA, Romundstad L, Hals EK, Kvarstein G, Stubhaug A. Assessment of pain. BrJ Anaesth 2008;101:17–24.Search in Google Scholar

[19] Becker N, Sjogren P, Bech P, Olsen AK, Eriksen J. Treatment outcome of chronic non-malignant pain patients managed in a Danish multidisciplinary pain centre compared to general practice: a randomised controlle trial. Pain 2000;84:203–11.Search in Google Scholar

[20] Heiskanen T, Roine RP, Kalso E. Multidisciplinary pain treatment - which patients do benefit? Scand J Pain 2012;3:201–7.Search in Google Scholar

[21] Meineche-Schmidt V, Jensen NH, Sjøgren P. Long-term outcome of multidisciplinary intervention of chronic non-cancer pain patients in a private setting. Scand J Pain 2012;3:99–105.Search in Google Scholar

[22] Becker N, Sjogren P, Bech P, Olsen AK, Eriksen J. Pain characteristics and demographics of patients attending a university-affiliated pain clinic in Toronto, Ontario. Pain Res Manag 2007;12:93–9.Search in Google Scholar

[23] Jensen HI, Plesner K, Kvorning N, Lundahl Krogh B, Kimper-Karl A. Associations between demographics and health-related quality of life for chronic non-malignant pain patients treated at a multidisciplinary paincentre: acohort study. Int J Qual Health Care 2016;28:86–91.Search in Google Scholar

[24] Lemming D. Multimodal Rehabilitation Programs (MMRP) for patients with longstanding complex pain conditions: the need for quality control with follow-up studies of patient outcomes. Scand J Pain 2016;10:104–5.Search in Google Scholar

[25] Gladwell PW, Badlan K, Cramp F, Palmer S. Direct and indirect benefits reported by users of transcutaneous electrical nerve stimulation for chronic musculoskeletal pain: qualitative exploration using patient interviews. Phys Ther 2015;95:1518–28.Search in Google Scholar

[26] Bennett MI, Hughes N, Johnson MJ. Methodological quality in randomised controlled trials oftranscutaneous electric nerve stimulation for pain: low fidelity may explain negative findings Pain 2011;152:1226–32.Search in Google Scholar

[27] Veehof MM, Trompetter HR, Bohlmeijer ET, Schreurs KMG. Acceptance- and mindfulness-based interventions for the treatment of chronic pain: a meta- analytic review. Cogn BehavTher 2016;45:5–31.Search in Google Scholar

[28] Pfeiffer E. A short portable mental status questionnaire for the assessment of organic brain deficit in elderly patients. J Am GeriatrSoc 1975;23:433–41.Search in Google Scholar

[29] Hallstam A, Lofgren M, Svensen C, Stalnacke BM. Patients with chronic pain: one-year follow-up of a multimodal rehabilitation programme at a pain clinic. Scand JPain 2016;10:36–42.Search in Google Scholar

[30] Swedish Quality Registry for Pain Rehabilitation: http://www.ucr.uu.se/nrsSearch in Google Scholar

[31] The EuroQol Group. EuroQol - a new facility for the measurement of health- related qualityoflife. Health Policy 1990;16:199–208.Search in Google Scholar

[32] Dolan P. Modeling valuations for EuroQol health states. Med Care 1997;35:1095–108.Search in Google Scholar

[33] Rabin R, Charro F. EQ-5D: a measure ofhealth status from the EuroQol Group. Ann Med 2001;33:337–43.Search in Google Scholar

[34] Walters S, Brazier J. Comparison of the minimally important difference for two health state utility measures: EQ-5D and SF-6D. Qual Life Res 2005;14:1523–32.Search in Google Scholar

[35] Woodforde JM, Merskey H. Some relationships between subjective measures of Pain. J Psychosom Res 1972;16:173–8.Search in Google Scholar

[36] Boonstra AM, Schihorst Preuber HR, Balk GA, Stewart RE. Cut-off points formild, moderate, and severe painon the visual analogue scale for pain in patients with chronic musculoskeletal pain. Pain 2014;155:2545–50.Search in Google Scholar

[37] Bastien CH, Vallieres A, Morin CM. Validation of the Insomnia Severity Index as an outcome measure for insomnia research. Sleep Med 2001;2:297–307.Search in Google Scholar

[38] Tait RC, Chibnall JT, Krause S. The Pain Disability Index: psychometric properties. Pain 1990;40:171–82.Search in Google Scholar

[39] Soer R, Reneman MF, Vroomen PC, Stegeman P, Coppes MH. Responsiveness and minimal clinically important change of the Pain Disability Index in patients with chronic back pain. Spine (Phila Pa 1976) 2012;37:711–5.Search in Google Scholar

[40] Zigmond AS, Snaith RP. The hospital anxiety and depression scale. Acta Psyc- hiatrScand 1983;67:361–70.Search in Google Scholar

[41] Lisspers J, Nygren A, Soderman E. Hospital Anxiety and Depression Scale (HAD): some psychometric data for a Swedish sample. Acta Psychiatr Scand 1997;96:281–6.Search in Google Scholar

[42] Antonovsky A. Unravelingthe Mystery of Health. Jossey-Bass, Inc. Publishers; 1987.Search in Google Scholar

[43] Bunketorp L, Carlsson J, Kowalski J, Stener-Victorin E. Evaluatingthe reliability of multi-item scales: a non-parametric approach to the ordered categorical structure of data collected with the Swedish version of the Tampa Scale for Kinesiophobia and the Self-Efficacy Scale. J Rehabil Med 2005;37: 330-4.Search in Google Scholar

[44] Luning Bergsten C, Lundberg M, Lindberg P, Elfving B. Change in kinesiophobia and its relation to activity limitation after multidisciplinary rehabilitation in patients with chronic back pain. Disabil Rehabil 2012;34:852–8.Search in Google Scholar

[45] Hagg O, Fritzell P, Nordwall A. The clinical importance of changes in outcome scores after treatment for chronic low back pain. Eur Spine J 2003;12: 12-20.Search in Google Scholar

[46] Yang M, Morin CM, Schaefer K, Wallenstein G. Interpreting score differences in the Insomnia Severity Index: using health-related outcomes to define the minimally important difference. Curr Med Res Opin 2009;25:2487–94.Search in Google Scholar

[47] Lillefjell M, Jakobsen K, Ernstsen L. The impact of a sense of coherence in employees with chronic pain. Work 2015;50:313–22.Search in Google Scholar

[48] Morin CM, Belleville G, Belanger L, Ivers H. The Insomnia Severity Index: psychometric indicators to detect insomnia cases and evaluate treatment response. Sleep 2011;34:601–8.Search in Google Scholar

[49] Stenberg G, Lundquist A, Fjellman-Wiklund A, Ahlgren C. Patterns of reported problems in women and men with back and neck pain: similarities and differences. J Rehabil Med 2014;46:668–75.Search in Google Scholar

[50] Torrance N, Lawson KD, Afolabi E, Bennett MI, Serpell MG, Dunn KM, Smith BH. Estimating the burden of disease in chronic pain with and without neuropathic characteristics: does the choice between the EQ-5D and SF-6D matter? Pain 2014;155:1996–2004.Search in Google Scholar

[51] Burstrom K, Johannesson M, Diderichsen F. Swedish population health-related qualityoflife results using the EQ-5D. Qual Life Res 2001;10:621–35.Search in Google Scholar

[52] Swedish Quality Registry for Pain Rehabilitation. [Report 2016: 2, Annual Report 2015 part 2] http://www.ucr.uu.se/nrs/index.php/arsrapporter [cited 0.08.16].Search in Google Scholar

[53] Merrick D, Sundelin G, Stalnacke BM. One-year follow-up of two different rehabilitation strategies for patients with chronic pain. J Rehabil Med 2012;44:764–73.Search in Google Scholar

[54] Soer R, Koke AJ, Speijer BL, Vroomen PC, Smeets RJ, Coppes MH, Reneman MF, Gross DP. Reference values of the pain disability index in patients with painful musculoskeletal and spinal disorders: a cross-national study. Spine (Phila Pa 1976) 2015;40:E545-51.Search in Google Scholar

[55] Scascighini L, Litschi M, Walti M, Sprott H. Effect of an interdisciplinary outpatient pain management program (IOPP) for chronic pain patients with and without migration background: aprospective, observational clinical study. Pain Med 2011;12:706–16.Search in Google Scholar

[56] Coretti S, Ruggeri M, McNamee P. The minimum clinically important difference for EQ-5D index: a critical review. Expert Rev Pharmacoecon Outcomes Res 2014;14:221–33.Search in Google Scholar

[57] Turk D, Dworkin RH, Revicki D, Harding G, Burke LB, Cella D, Cleeland CS, Cowan P, Farrar JT, Hertz S, Max MB, Rappaport BA. Identifying important outcome domains for chronic pain clinical trials: an IMMPACT survey of people with pain. Pain 2008;137:276–85.Search in Google Scholar

[58] Turk DC, Dworkin RH, Allen RR, Bellamy N, Brandenburg N, Carr DB, Cleeland C, Dionne R, Farrar JT, Galer BS, Hewitt DJ, Jadad AR, Katz NP, Kramer LD, Manning DC, McCormick CG, McDermott MP, McGrath P, Quessy S, Rappaport BA, Robinson JP, Royal MA, Simon L, Stauffer JW, Stein W, Tollett J, Witter J. Core outcome domains forchronic pain clinical trials: IMMPACT recommendations. Pain 2003;106:337–45.Search in Google Scholar

[59] Dragioti E, Wiklund T, Alf5ldi P, Gerdle P. The Swedish version of the Insomnia Severity Index: factor structure analysis and psychometric properties inchronic pain patients. Scand J Pain 2015;9:22–7.Search in Google Scholar

[60] Norrefalk JR, Littwold-Poljo A, Ryhle L, Jansen GB. Effect on work ability after team evaluation of functioning regarding pain, self-rated disability, and work ability assessment. J Multidiscip Healthc 2010;3:155–9.Search in Google Scholar
Received: 2016-05-18
Revised: 2016-08-08
Accepted: 2016-08-15
Published Online: 2017-10-01
Published in Print: 2017-10-01

© 2016 Scandinavian Association for the Study of Pain

Articles in the same Issue

  1. Observational study
  2. Perceived sleep deficit is a strong predictor of RLS in multisite pain – A population based study in middle aged females
  3. Clinical pain research
  4. Prospective, double blind, randomized, controlled trial comparing vapocoolant spray versus placebo spray in adults undergoing intravenous cannulation
  5. Clinical pain research
  6. The Functional Barometer — An analysis of a self-assessment questionnaire with ICF-coding regarding functional/activity limitations and quality of life due to pain — Differences in age gender and origin of pain
  7. Clinical pain research
  8. Clinical outcome following anterior arthrodesis in patients with presumed sacroiliac joint pain
  9. Observational study
  10. Chronic disruptive pain in emerging adults with and without chronic health conditions and the moderating role of psychiatric disorders: Evidence from a population-based cross-sectional survey in Canada
  11. Educational case report
  12. Management of patients with pain and severe side effects while on intrathecal morphine therapy: A case study
  13. Clinical pain research
  14. Behavioral inhibition, maladaptive pain cognitions, and function in patients with chronic pain
  15. Observational study
  16. Comparison of patients diagnosed with “complex pain” and “somatoform pain”
  17. Original experimental
  18. Patient perspectives on wait times and the impact on their life: A waiting room survey in a chronic pain clinic
  19. Topical review
  20. New evidence for a pain personality? A critical review of the last 120 years of pain and personality
  21. Clinical pain research
  22. A multi-facet pain survey of psychosocial complaints among patients with long-standing non-malignant pain
  23. Clinical pain research
  24. Pain patients’ experiences of validation and invalidation from physicians before and after multimodal pain rehabilitation: Associations with pain, negative affectivity, and treatment outcome
  25. Observational study
  26. Long-term treatment in chronic noncancer pain: Results of an observational study comparing opioid and nonopioid therapy
  27. Clinical pain research
  28. COMBAT study – Computer based assessment and treatment – A clinical trial evaluating impact of a computerized clinical decision support tool on pain in cancer patients
  29. Original experimental
  30. Quantitative sensory tests fairly reflect immediate effects of oxycodone in chronic low-back pain
  31. Editorial comment
  32. Spatial summation of pain and its meaning to patients
  33. Original experimental
  34. Effects of validating communication on recall during a pain-task in healthy participants
  35. Original experimental
  36. Comparison of spatial summation properties at different body sites
  37. Editorial comment
  38. Behavioural inhibition in the context of pain: Measurement and conceptual issues
  39. Clinical pain research
  40. A randomized study to evaluate the analgesic efficacy of a single dose of the TRPV1 antagonist mavatrep in patients with osteoarthritis
  41. Editorial comment
  42. Quantitative sensory tests (QST) are promising tests for clinical relevance of anti–nociceptive effects of new analgesic treatments
  43. Educational case report
  44. Pregabalin as adjunct in a multimodal pain therapy after traumatic foot amputation — A case report of a 4-year-old girl
  45. Editorial comment
  46. Severe side effects from intrathecal morphine for chronic pain after repeated failed spinal operations
  47. Editorial comment
  48. Opioids in chronic pain – Primum non nocere
  49. Editorial comment
  50. Finally a promising analgesic signal in a long-awaited new class of drugs: TRPV1 antagonist mavatrep in patients with osteoarthritis (OA)
  51. Observational study
  52. The relationship between chronic musculoskeletal pain, anxiety and mindfulness: Adjustments to the Fear-Avoidance Model of Chronic Pain
  53. Clinical pain research
  54. Opioid tapering in patients with prescription opioid use disorder: A retrospective study
  55. Editorial comment
  56. Sleep, widespread pain and restless legs — What is the connection?
  57. Editorial comment
  58. Broadening the fear-avoidance model of chronic pain?
  59. Observational study
  60. Identifying characteristics of the most severely impaired chronic pain patients treated at a specialized inpatient pain clinic
  61. Editorial comment
  62. The burden of central anticholinergic drugs increases pain and cognitive dysfunction. More knowledge about drug-interactions needed
  63. Editorial comment
  64. A case-history illustrates importance of knowledge of drug-interactions when pain-patients are prescribed non-pain drugs for co-morbidities
  65. Editorial comment
  66. Why can multimodal, multidisciplinary pain clinics not help all chronic pain patients?
  67. Topical review
  68. Individual variability in clinical effect and tolerability of opioid analgesics – Importance of drug interactions and pharmacogenetics
  69. Editorial comment
  70. A new treatable chronic pain diagnosis? Flank pain caused by entrapment of posterior cutaneous branch of intercostal nerves, lateral ACNES coined LACNES
  71. Clinical pain research
  72. PhKv a toxin isolated from the spider venom induces antinociception by inhibition of cholinesterase activating cholinergic system
  73. Clinical pain research
  74. Lateral Cutaneous Nerve Entrapment Syndrome (LACNES): A previously unrecognized cause of intractable flank pain
  75. Editorial comment
  76. Towards a structured examination of contextual flexibility in persistent pain
  77. Clinical pain research
  78. Context sensitive regulation of pain and emotion: Development and initial validation of a scale for context insensitive avoidance
  79. Editorial comment
  80. Is the search for a “pain personality” of added value to the Fear-Avoidance-Model (FAM) of chronic pain?
  81. Editorial comment
  82. Importance for patients of feeling accepted and understood by physicians before and after multimodal pain rehabilitation
  83. Editorial comment
  84. A glimpse into a neglected population – Emerging adults
  85. Observational study
  86. Assessment and treatment at a pain clinic: A one-year follow-up of patients with chronic pain
  87. Clinical pain research
  88. Randomized, double-blind, placebo-controlled, dose-escalation study: Investigation of the safety, pharmacokinetics, and antihyperalgesic activity of L-4-chlorokynurenine in healthy volunteers
  89. Clinical pain research
  90. Prevalence and characteristics of chronic pain: Experience of Niger
  91. Observational study
  92. The use of rapid onset fentanyl in children and young people for breakthrough cancer pain
  93. Original experimental
  94. Acid-induced experimental muscle pain and hyperalgesia with single and repeated infusion in human forearm
  95. Original experimental
  96. Swearing as a response to pain: A cross-cultural comparison of British and Japanese participants
  97. Clinical pain research
  98. The cognitive impact of chronic low back pain: Positive effect of multidisciplinary pain therapy
  99. Clinical pain research
  100. Central sensitization associated with low fetal hemoglobin levels in adults with sickle cell anemia
  101. Topical review
  102. Targeting cytokines for treatment of neuropathic pain
  103. Original experimental
  104. What constitutes back pain flare? A cross sectional survey of individuals with low back pain
  105. Original experimental
  106. Coping with pain in intimate situations: Applying the avoidance-endurance model to women with vulvovaginal pain
  107. Clinical pain research
  108. Chronic low back pain and the transdiagnostic process: How do cognitive and emotional dysregulations contribute to the intensity of risk factors and pain?
  109. Original experimental
  110. The impact of the Standard American Diet in rats: Effects on behavior, physiology and recovery from inflammatory injury
  111. Educational case report
  112. Erector spinae plane (ESP) block in the management of post thoracotomy pain syndrome: A case series
  113. Original experimental
  114. Hyperbaric oxygenation alleviates chronic constriction injury (CCI)-induced neuropathic pain and inhibits GABAergic neuron apoptosis in the spinal cord
  115. Observational study
  116. Predictors of chronic neuropathic pain after scoliosis surgery in children
  117. Clinical pain research
  118. Hospitalization due to acute exacerbation of chronic pain: An intervention study in a university hospital
  119. Clinical pain research
  120. A novel miniature, wireless neurostimulator in the management of chronic craniofacial pain: Preliminary results from a prospective pilot study
  121. Clinical pain research
  122. Implicit evaluations and physiological threat responses in people with persistent low back pain and fear of bending
  123. Original experimental
  124. Unpredictable pain timings lead to greater pain when people are highly intolerant of uncertainty
  125. Original experimental
  126. Initial validation of the exercise chronic pain acceptance questionnaire
  127. Clinical pain research
  128. Exploring patient experiences of a pain management centre: A qualitative study
  129. Clinical pain research
  130. Narratives of life with long-term low back pain: A follow up interview study
  131. Observational study
  132. Pain catastrophizing, perceived injustice, and pain intensity impair life satisfaction through differential patterns of physical and psychological disruption
  133. Clinical pain research
  134. Chronic pain disrupts ability to work by interfering with social function: A cross-sectional study
  135. Original experimental
  136. Evaluation of external vibratory stimulation as a treatment for chronic scrotal pain in adult men: A single center open label pilot study
  137. Observational study
  138. Impact of analgesics on executive function and memory in the Alzheimer’s Disease Neuroimaging Initiative Database
  139. Clinical pain research
  140. Visualization of painful inflammation in patients with pain after traumatic ankle sprain using [11C]-D-deprenyl PET/CT
  141. Original experimental
  142. Developing a model for measuring fear of pain in Norwegian samples: The Fear of Pain Questionnaire Norway
  143. Topical review
  144. Psychoneuroimmunological approach to gastrointestinal related pain
  145. Letter to the Editor
  146. Do we need an updated definition of pain?
  147. Narrative review
  148. Is acetaminophen safe in pregnancy?
  149. Book Review
  150. Physical Diagnosis of Pain
  151. Book Review
  152. Advances in Anesthesia
  153. Book Review
  154. Atlas of Pain Management Injection Techniques
  155. Book Review
  156. Sedation: A Guide to Patient Management
  157. Book Review
  158. Basics of Anesthesia
https://doi.org/10.1016/j.sjpain.2016.08.004
Keywords for this article
Chronic pain; Pain clinic; Longitudinal observational study; Pain treatment; Insomnia

Articles in the same Issue

  1. Observational study
  2. Perceived sleep deficit is a strong predictor of RLS in multisite pain – A population based study in middle aged females
  3. Clinical pain research
  4. Prospective, double blind, randomized, controlled trial comparing vapocoolant spray versus placebo spray in adults undergoing intravenous cannulation
  5. Clinical pain research
  6. The Functional Barometer — An analysis of a self-assessment questionnaire with ICF-coding regarding functional/activity limitations and quality of life due to pain — Differences in age gender and origin of pain
  7. Clinical pain research
  8. Clinical outcome following anterior arthrodesis in patients with presumed sacroiliac joint pain
  9. Observational study
  10. Chronic disruptive pain in emerging adults with and without chronic health conditions and the moderating role of psychiatric disorders: Evidence from a population-based cross-sectional survey in Canada
  11. Educational case report
  12. Management of patients with pain and severe side effects while on intrathecal morphine therapy: A case study
  13. Clinical pain research
  14. Behavioral inhibition, maladaptive pain cognitions, and function in patients with chronic pain
  15. Observational study
  16. Comparison of patients diagnosed with “complex pain” and “somatoform pain”
  17. Original experimental
  18. Patient perspectives on wait times and the impact on their life: A waiting room survey in a chronic pain clinic
  19. Topical review
  20. New evidence for a pain personality? A critical review of the last 120 years of pain and personality
  21. Clinical pain research
  22. A multi-facet pain survey of psychosocial complaints among patients with long-standing non-malignant pain
  23. Clinical pain research
  24. Pain patients’ experiences of validation and invalidation from physicians before and after multimodal pain rehabilitation: Associations with pain, negative affectivity, and treatment outcome
  25. Observational study
  26. Long-term treatment in chronic noncancer pain: Results of an observational study comparing opioid and nonopioid therapy
  27. Clinical pain research
  28. COMBAT study – Computer based assessment and treatment – A clinical trial evaluating impact of a computerized clinical decision support tool on pain in cancer patients
  29. Original experimental
  30. Quantitative sensory tests fairly reflect immediate effects of oxycodone in chronic low-back pain
  31. Editorial comment
  32. Spatial summation of pain and its meaning to patients
  33. Original experimental
  34. Effects of validating communication on recall during a pain-task in healthy participants
  35. Original experimental
  36. Comparison of spatial summation properties at different body sites
  37. Editorial comment
  38. Behavioural inhibition in the context of pain: Measurement and conceptual issues
  39. Clinical pain research
  40. A randomized study to evaluate the analgesic efficacy of a single dose of the TRPV1 antagonist mavatrep in patients with osteoarthritis
  41. Editorial comment
  42. Quantitative sensory tests (QST) are promising tests for clinical relevance of anti–nociceptive effects of new analgesic treatments
  43. Educational case report
  44. Pregabalin as adjunct in a multimodal pain therapy after traumatic foot amputation — A case report of a 4-year-old girl
  45. Editorial comment
  46. Severe side effects from intrathecal morphine for chronic pain after repeated failed spinal operations
  47. Editorial comment
  48. Opioids in chronic pain – Primum non nocere
  49. Editorial comment
  50. Finally a promising analgesic signal in a long-awaited new class of drugs: TRPV1 antagonist mavatrep in patients with osteoarthritis (OA)
  51. Observational study
  52. The relationship between chronic musculoskeletal pain, anxiety and mindfulness: Adjustments to the Fear-Avoidance Model of Chronic Pain
  53. Clinical pain research
  54. Opioid tapering in patients with prescription opioid use disorder: A retrospective study
  55. Editorial comment
  56. Sleep, widespread pain and restless legs — What is the connection?
  57. Editorial comment
  58. Broadening the fear-avoidance model of chronic pain?
  59. Observational study
  60. Identifying characteristics of the most severely impaired chronic pain patients treated at a specialized inpatient pain clinic
  61. Editorial comment
  62. The burden of central anticholinergic drugs increases pain and cognitive dysfunction. More knowledge about drug-interactions needed
  63. Editorial comment
  64. A case-history illustrates importance of knowledge of drug-interactions when pain-patients are prescribed non-pain drugs for co-morbidities
  65. Editorial comment
  66. Why can multimodal, multidisciplinary pain clinics not help all chronic pain patients?
  67. Topical review
  68. Individual variability in clinical effect and tolerability of opioid analgesics – Importance of drug interactions and pharmacogenetics
  69. Editorial comment
  70. A new treatable chronic pain diagnosis? Flank pain caused by entrapment of posterior cutaneous branch of intercostal nerves, lateral ACNES coined LACNES
  71. Clinical pain research
  72. PhKv a toxin isolated from the spider venom induces antinociception by inhibition of cholinesterase activating cholinergic system
  73. Clinical pain research
  74. Lateral Cutaneous Nerve Entrapment Syndrome (LACNES): A previously unrecognized cause of intractable flank pain
  75. Editorial comment
  76. Towards a structured examination of contextual flexibility in persistent pain
  77. Clinical pain research
  78. Context sensitive regulation of pain and emotion: Development and initial validation of a scale for context insensitive avoidance
  79. Editorial comment
  80. Is the search for a “pain personality” of added value to the Fear-Avoidance-Model (FAM) of chronic pain?
  81. Editorial comment
  82. Importance for patients of feeling accepted and understood by physicians before and after multimodal pain rehabilitation
  83. Editorial comment
  84. A glimpse into a neglected population – Emerging adults
  85. Observational study
  86. Assessment and treatment at a pain clinic: A one-year follow-up of patients with chronic pain
  87. Clinical pain research
  88. Randomized, double-blind, placebo-controlled, dose-escalation study: Investigation of the safety, pharmacokinetics, and antihyperalgesic activity of L-4-chlorokynurenine in healthy volunteers
  89. Clinical pain research
  90. Prevalence and characteristics of chronic pain: Experience of Niger
  91. Observational study
  92. The use of rapid onset fentanyl in children and young people for breakthrough cancer pain
  93. Original experimental
  94. Acid-induced experimental muscle pain and hyperalgesia with single and repeated infusion in human forearm
  95. Original experimental
  96. Swearing as a response to pain: A cross-cultural comparison of British and Japanese participants
  97. Clinical pain research
  98. The cognitive impact of chronic low back pain: Positive effect of multidisciplinary pain therapy
  99. Clinical pain research
  100. Central sensitization associated with low fetal hemoglobin levels in adults with sickle cell anemia
  101. Topical review
  102. Targeting cytokines for treatment of neuropathic pain
  103. Original experimental
  104. What constitutes back pain flare? A cross sectional survey of individuals with low back pain
  105. Original experimental
  106. Coping with pain in intimate situations: Applying the avoidance-endurance model to women with vulvovaginal pain
  107. Clinical pain research
  108. Chronic low back pain and the transdiagnostic process: How do cognitive and emotional dysregulations contribute to the intensity of risk factors and pain?
  109. Original experimental
  110. The impact of the Standard American Diet in rats: Effects on behavior, physiology and recovery from inflammatory injury
  111. Educational case report
  112. Erector spinae plane (ESP) block in the management of post thoracotomy pain syndrome: A case series
  113. Original experimental
  114. Hyperbaric oxygenation alleviates chronic constriction injury (CCI)-induced neuropathic pain and inhibits GABAergic neuron apoptosis in the spinal cord
  115. Observational study
  116. Predictors of chronic neuropathic pain after scoliosis surgery in children
  117. Clinical pain research
  118. Hospitalization due to acute exacerbation of chronic pain: An intervention study in a university hospital
  119. Clinical pain research
  120. A novel miniature, wireless neurostimulator in the management of chronic craniofacial pain: Preliminary results from a prospective pilot study
  121. Clinical pain research
  122. Implicit evaluations and physiological threat responses in people with persistent low back pain and fear of bending
  123. Original experimental
  124. Unpredictable pain timings lead to greater pain when people are highly intolerant of uncertainty
  125. Original experimental
  126. Initial validation of the exercise chronic pain acceptance questionnaire
  127. Clinical pain research
  128. Exploring patient experiences of a pain management centre: A qualitative study
  129. Clinical pain research
  130. Narratives of life with long-term low back pain: A follow up interview study
  131. Observational study
  132. Pain catastrophizing, perceived injustice, and pain intensity impair life satisfaction through differential patterns of physical and psychological disruption
  133. Clinical pain research
  134. Chronic pain disrupts ability to work by interfering with social function: A cross-sectional study
  135. Original experimental
  136. Evaluation of external vibratory stimulation as a treatment for chronic scrotal pain in adult men: A single center open label pilot study
  137. Observational study
  138. Impact of analgesics on executive function and memory in the Alzheimer’s Disease Neuroimaging Initiative Database
  139. Clinical pain research
  140. Visualization of painful inflammation in patients with pain after traumatic ankle sprain using [11C]-D-deprenyl PET/CT
  141. Original experimental
  142. Developing a model for measuring fear of pain in Norwegian samples: The Fear of Pain Questionnaire Norway
  143. Topical review
  144. Psychoneuroimmunological approach to gastrointestinal related pain
  145. Letter to the Editor
  146. Do we need an updated definition of pain?
  147. Narrative review
  148. Is acetaminophen safe in pregnancy?
  149. Book Review
  150. Physical Diagnosis of Pain
  151. Book Review
  152. Advances in Anesthesia
  153. Book Review
  154. Atlas of Pain Management Injection Techniques
  155. Book Review
  156. Sedation: A Guide to Patient Management
  157. Book Review
  158. Basics of Anesthesia
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Have an idea on how to improve our website?
Please write us.
© 2025 De Gruyter Brill
Downloaded on 29.12.2025 from https://www.degruyterbrill.com/document/doi/10.1016/j.sjpain.2016.08.004/html
Scroll to top button