Volume 13, Issue 1

Background Pressure pain thresholds (PPTs) in a non-painful body area are known to be affected in some chronic pain states. The aim of this study is to investigate PPTs in a pain-free body part in relation to pain persistence and intensity in patients with musculoskeletal pain. Methods Patients with musculoskeletal pain were divided into three different pain groups: acute pain (pain duration < 3 months, n = 38), regularly recurrent pain (regularly recurrent pain duration > 3 months, n = 56), persistent pain (persistent pain duration >3 months, n = 52) and a healthy control group ( n = 51). PPT measures were conducted over the tibialis anterior muscle on the right leg in all groups. Results The persistent pain group showed significantly lower PPTs over the tibialis anterior muscle compared to controls. No significant differences were found between the acute and regularly recurrent pain groups compared to healthy controls. Significant correlations, albeit small, were found between pain intensity and PPTs. Conclusions Increased deep pain sensitivity was found in patients with persistent musculoskeletal pain, but not in regularly recurrent pain or in acute pain. Yet, a limitation of the study is that it did not have sufficient power to detect small levels of increased deep pain sensitivity among the latter groups when compared to healthy controls. Implications Knowledge about increased general hypersensitivity in persistent musculoskeletal pain could be important in clinical treatment.

Background and aims Patient reported outcomes (PROs) are increasingly being implemented into the care of patients with cancer. The use of a standard set of PROs (e.g., pain) in cancer is becoming established and there is interest in what additional PROs might provide valuable information. The goal of this observational study was to examine how the PROs of self-efficacy for pain and other symptoms assessed at the point of service were associated with pain, symptom severity and distress, and physical and psychosocial functioning in a sample of breast and gastrointestinal patients. We also sought to examine differences in these relationships by cancer type (breast and gastrointestinal) as well as understand differences in self-assessment mode (paper/pencil or electronic tablet). Methods 178 patients with breast ( n = 65) and gastrointestinal cancer ( n = 113) completed the Chronic Pain Self Efficacy Scale, M.D. Anderson Symptom Inventory, and Functional Assessment of Cancer Therapy – General questionnaires. Measures were completed with paper and pencil and electronically using a tablet computer while patients waited for their clinical appointment. Responses from the initial completed questionnaires on both the paper and electronic instruments were analyzed. Results Patients’ self-efficacy scores for pain and other symptoms correlated positively with pain, symptom severity and distress, and physical and psychosocial functioning; patients with lower levels of self-efficacy reported poorer outcomes and functioning overall. The results were independent of cancer type and mode of assessment. No statistically significant differences were found in the PROs when collected by electronic technology versus paper-pencil mode; patients were very satisfied with using the tablet computer to complete the PRO measures. Conclusions and implications Our results suggest that self-efficacy for pain and symptom management may be a beneficial addition to clinic-based PRO assessment batteries for patients with cancer and other chronic diseases. Existing short, validated symptom self-efficacy scales could easily be integrated into clinical practice to help healthcare providers identify patients that might benefit from intervention. Study results also support existing research that suggests electronic approaches are a practical way to collect PRO data, including self-efficacy data, in the clinic. Overall, our data suggest that patients who have particularly low levels of self-efficacy for pain and symptom management may be at risk for higher levels of pain and disability. Thus, if self-efficacy for pain and symptom management were routinely collected at the time of clinical service, psychosocial interventions to improve self-efficacy for pain and symptom management, and in turn overall quality of life, could be implemented in a timely fashion.

Background and aims Recent evidence demonstrated that complex regional pain syndrome (CRPS) is associated with a larger than normal somatosensory (S1) representation of the healthy hand. The most intuitive mechanism for this apparent enlargement is increased, i.e. compensatory, use of the healthy hand. We investigated whether enlargement of the S1 representation of the healthy hand is associated with compensatory use in response to CRPS. Specifically, we were interested in whether the size of the S1 representation of the healthy hand is associated with the severity of functional impairment of the CRPS-affected hand. We were also interested in whether CRPS duration might be positively associated with the size of the representation of the healthy hand in S1. Methods Using functional magnetic resonance imaging (fMRI) data from our previous investigation, the size of the S1 representation of the healthy hand in CRPS patients ( n = 12) was standardised to that of a healthy control sample ( n = 10), according to hand dominance. Responses to questionnaires on hand function, overall function and self-efficacy were used to gather information on hand use in participants. Multiple regression analyses investigated whether the S1 representation was associated with compensatory use. We inferred compensatory use with the interaction between reported use of the CRPS-affected hand and (a) reported overall function, and (b) self-efficacy. We tested the correlation between pain duration and the size of the S1 representation of the healthy hand with Spearman’s rho. Results The relationship between the size of the S1 representation of the healthyh and and the interaction between use of the affected hand and overall function was small and non-significant ( β =-5.488×10 -5 , 95% C.I. –0.001, 0.001). The relationship between the size of the S1 representation of the healthy hand and the interaction between use of the affected hand and self-efficacy was also small and non-significant ( β =-6.027×10 -6 , 95% C.I. –0.001, 0.001). The S1 enlargement of the healthy hand was not associated with pain duration (Spearman’s rho = –0.14, p = 0.67). Conclusion Our exploration did not yield evidence of any relationship between the size of the healthy hand representation in S1 and the severity of functional impairment of the CRPS-affected hand, relative to overall hand use or to self-efficacy. There was also no evidence of an association between the size of the healthy hand representation in S1 and pain duration. The enlarged S1 representation of the healthy hand does not relate to self-reported function and impairment in CRPS. Implications While this study had a hypothesis-generating nature and the sample was small, there were no trends to suggest compensatory use as the mechanism underlying the apparent enlargement of the healthy hand in S1. Further studies are needed to investigate the possibility that inter-hemispheric differences seen in S1 in CRPS may be present prior to the development of the disorder.

Background Spine surgery candidates are commonly treated with long-term opioid analgesia. However, chronic opioid analgesia is associated with poor pain control, psychological distress, decreased functional status and operative complications. Therefore, our medical centre piloted an outpatient biopsychosocial interdisciplinary opioid reduction program for spine surgery candidates on chronic opioid analgesia. Methods Our case series reviews the outcomes of the first 5 interdisciplinary program completers. Data was collected on admission to the program, preoperatively at completion of the program, and 1 month postoperatively. We recorded changes in pain interference scores, physical functioning, and symptoms of depression and anxiety as captured by the Patient-Reported Outcome Measurement Information System (PROMIS-29) Profile. Results The mean duration of the preoperative opioid reduction program was 6–7 weeks. The mean morphine equivalent daily dose (SD) decreased from 238.2 (226.9) mg on admission to 157.1 (161.0) mg preoperatively and 139.1 (84.0) mg one month postoperatively. Similarly, the mean pain interference score (SD) decreased from 72.4 (5.1) on admission to 66.5 (6.9) preoperatively and 67.7 (5.4) one month postoperatively. The preoperative opioid dose and pain interference scores decreased in all 5 patients, but one month postoperatively increased in one patient related to a surgical complication. Pre- and postoperative depression, anxiety and fatigue improved in all patients. Satisfaction with participation in social roles, sleep disturbances, and physical functioning improved in most patients. Conclusions Pre- and post-operative pain improved despite the opioid dose being tapered. These preliminary data suggest that a short-term outpatient preoperative interdisciplinary biopsychosocial opioid reduction program is safe, feasible, and improves patient-centred outcomes. Implications Our preliminary data support the rationale for expansion of the opioid reduction program; opioid use and pain should be evaluated in all surgical candidates. These findings need to be replicated in larger studies.

Background Pain is one of the most common symptoms treated in emergency department (ED). Pain may cause suffering and disability for the patient. Inadequate pain management may be associated with increased risk of complications such as sleep disturbance, delirium and depression. Previous studies conclude that pain management in ED is insufficient and inadequate. Yet, little is known about patients’ own experience regarding pain management in ED. Objective The aim of this study was to explore the satisfaction of pain management in patients having acute musculoskeletal injuries before and after implementation of mandatory documentation regarding pain assessment in the ED. Method An observational pre-post intervention study design was used. The study was conducted on patients having acute musculoskeletal injuries such as soft tissue injury, back pain or wrist/arm/leg/foot fractures in a 24-h adult (>15 years) ED at a public urban teaching hospital in Stockholm, Sweden. Data was collected by an interview based on a questionnaire. Results A total of 160 patients answered the questionnaire. In the pre- ( n = 80) and post-intervention ( n = 80) groups, 91/95% experienced pain in the ED. A significant difference ( p < 0.003) was found during the post-intervention period, with more patients receiving analgesics compared to the pre-intervention group. A significant decline (p < 0.03) in patients’ own reported pain intensity at discharge was found between the groups. Patients’ reported satisfaction on pain management in the ED increased in the post-intervention group, but the difference was not statistically significantly. Conclusion Patients’ satisfaction with pain management increased, but not statistically significantly. However, both percentages of patients receiving analgesic drugs increased and pain intensity decrease at discharge were statistically significant after the intervention that made nurses obliged to register pain. Implication According to the findings of this study, mandatory pain documentation facilitates pain management in the ED, but there is still room for improvement. Additional actions are needed to improve patients’ satisfaction on pain management in the ED. Mandatory pain documentation in combination with person-centred care could be a way of improving patients’ satisfaction on pain management. Effective pain management is an important quality measure, and should be focused on in acute care in the ED. By routinely asking patients to report the pain intensity at discharge, the ED personnel can have direct feedback about the factual pain management. RNs may also be encouraged to use intravenous analgesics in higher extent when the patients have very severe pain.

Background and aims Single-shot spinal with bupivacaine plus fentanyl or sufentanil is commonly used as analgesia during labour, but the short duration limits the clinical feasibility. Different drugs have been added to prolong the analgesic duration. The additional effect of intra-thecal morphine has been studied during labour pain as well as after surgery. We assessed whether adding morphine to intra-thecal bupivacaine + fentanyl or sufentanil prolongs pain relief during labour. Methods Meta-analysis of placebo-controlled randomized clinical trials of analgesia prolongation after single-shot intrathecal morphine ≤250µg during labour when given in combination with bupivacaine + fentanyl or sufentanil. After identifying 461 references, 24 eligible studies were evaluated after excluding duplicate publications, case reports, studies of analgesia after caesarean delivery, and epidural labour analgesia. Mean duration in minutes was the primary outcome measure and was included in the calculation of the standardized mean difference. Duration was defined as the time between a single shot spinal until patient request of rescue analgesia. All reported side effects were registered. Results of individual trials were combined using a random effect model. Cochrane tool was used to assess risk of bias. Results Five randomized placebo-controlled clinical trials (286 patients) were included in the metaanalysis. A dose of 50–250µg intrathecal morphine prolonged labour analgesia by a mean of 60.6 min (range 3–155 min). Adding morphine demonstrated a medium beneficial effect as we found a pooled effect of standardized mean difference = 0.57 (95% CI: –0.10 to 1.24) with high heterogeneity ( I 2 =88.1%). However, the beneficial effect was statistically non-significant ( z =1.66, p = 0.096). The lower-bias trials showed a small statistically non-significant beneficial effect with lower heterogeneity. In influential analysis, that excluded one study at a time from the meta-analysis, the effect size appears unstable and the results indicate no robustness of effect. Omitting the study with highest effects size reduces the pooled effect markedly and that study suffers from inadequate concealment of treatment allocation and blinding. Trial quality was generally low, and there were too few trials to explore sources of heterogeneity in meta-regression and stratified analyses. In general, performing meta-analyses on a small number of trials are possible and may be helpful if one is aware of the limitations. As few as one more placebo-controlled trial would increase the reliability greatly. Conclusions Evidence from this systematic review suggests a possible beneficial prolonging effect of adding morphine to spinal analgesia with bupivacaine + fentanyl or +sufentanil during labour. The study quality was low and heterogeneity high. No severe side effects were reported. More adequately-powered randomized trials with low bias are needed to determine the benefits and harms of adding morphine to spinal local anaesthetic analgesia during labour. Implications Epidural analgesia is documented as the most effective method for providing pain relief during labour, but from a global perspective most women in labour have no access to epidural analgesia. Adding morphine to single shot spinal injection of low dose bupivacaine, fentanyl or sufentanil may be efficacious but needs to be investigated.

Background The fear-avoidance model of chronic pain has established avoidance as a predictor of negative outcomes in chronic pain patients. Avoidance, or deliberate attempts to suppress or prevent unwanted experiences (e.g., pain), has been studied extensively, with multiple reviews implicating this behavior as a predictor of disability, physical disuse, and depression. Despite hundreds of studies examining the associations between different components of this model (i.e., catastrophizing, fear, avoidance, depression), the association between fear-avoidance and pain intensity has remained unclear. The present study seeks to clarify this association across samples. Method The present analyses synthesize the literature (articles from PsycInfo, PubMed, and ProQuest) to determine if fear-avoidance and pain intensity are consistently correlated across studies, samples, and measures. Eligible studies measured pain intensity and fear-avoidance cross-sectionally in chronic pain patients. The search resulted in 118 studies eligible for inclusion. A random-effects model was used to estimate the weighted mean effect size. Comprehensive Meta-Analysis software was used for all analyses. Moderation analyses elucidate the variables that affect the strength of this association. Meta-regression and meta-ANOVA analyses were conducted to examine moderating variables. Moderator variables include demographic characteristics, pain characteristics, study characteristics, and national cultural characteristics (using Hofstede’s cultural dimensions). Publication bias was examined using the funnel plot and the p-curve. Results Results indicate a small-to-moderate positive association between fear-avoidance and pain intensity. The results were stable across characteristics of the sample, including mean age, gender distribution, marital status, and duration of pain. Moderation analyses indicate that the measures utilized and cultural differences affect the strength of this association. Weaker effect sizes were observed for studies that utilized measures of experiential avoidance when compared to studies that utilized pain-specific fear-avoidance measures. Studies that utilized multiple measures of fear-avoidance had stronger effect sizes than studies that utilized a single measure of fear-avoidance. Three of Hofstede’s cultural dimensions moderated the association, including Power Distance Index, Individualism versus Collectivism, and Indulgence versus Restraint. Conclusions The present meta-analysis synthesizes the results from studies examining the association between fear-avoidance and pain intensity among individuals with chronic pain. The positive association indicates that those with increased fear-avoidance have higher pain intensity, and those with higher pain intensity have increased fear-avoidance. Findings indicate that cultural differences and measurement instruments are important to consider in understanding the variables that affect this association. The significant cultural variations may indicate that it is important to consider the function of avoidance behavior in different cultures in an effort to better understand each patient’s cultural beliefs, as well as how these beliefs are related to pain and associated coping strategies. Implications The results from the current meta-analysis can be used to inform interventions for patients with chronic pain. In particular, those with more intense pain or increased fear-avoidance should be targeted for prevention and intervention work. Within the intervention itself, avoidance should be undermined and established as an ineffective strategy to manage pain in an effort to prevent disability, depression, and physical deconditioning.

Background This is a secondary publication of a PhD thesis. Local infiltration analgesia (LIA) is a new multimodal wound infiltration method for treating postoperative pain after knee and hip arthroplasty. This method is based on systematic infiltration of a mixture of ropivacaine, a long acting local anaesthetic, ketorolac, a cyclooxygenase inhibitor (NSAID), and adrenalin around all structures subject to surgical trauma in knee and hip arthroplasty. Aims Paper I: to assess whether pain relief after LIA in total knee arthroplasty (TKA) is as effective as femoral block. Paper II: to assess whether the plasma concentration of ropivacaine and ketorolac after LIA in TKA reaches levels linked to toxicity. Paper III: to assess whether the plasma concentration of unbound ropivacaine after LIA in THA reaches levels linked to toxicity and if it is higher in THA as compared to TKA. Paper IV: to assess whether the plasma concentration of ketorolac after LIA in THA reaches levels linked to toxicity, and whether administration of ketorolac in LIA is safer as compared to the intramuscular route. Methods Two patient cohorts of 40 patients scheduled for elective total knee arthroplasty (TKA) and 15 patients scheduled for total hip arthroplasty (THA) contributed to this work. In a randomized trial the efficacy of LIA in TKA with regard to pain at rest and upon movement was compared to femoral block. Results Both methods result in a high quality pain relief and similar morphine consumption during the 24 h monitoring period. In the same patient cohort the maximal total plasma concentration of ropivacaine was below the established toxic threshold for most patients. All patients in the THA cohort were subjected to the routine LIA protocol. In these patients both the total and unbound plasma concentration of ropivacaine was determined. The concentration was below the established toxic threshold. As ropivacaine binds to α–1 acid glycoprotein (AAG) we assessed the possibility that increased AAG may decrease the unbound concentration of ropivacaine. A 40% increase in AAG was detected during the first 24 h after surgery, however the fraction of unbound ropivacaine remained the same. There was a trend towards increased C max of ropivacaine with increasing age and decreasing creatinine clearance but the statistical power was too low to draw any conclusion. Administration of 30 mg ketorolac according to the LIA protocol both in TKA and THA resulted in a similar C max as previously reported after 10 mg intramuscular ketorolac. Neither age, nor body weight or BMI, nor creatinine clearance, correlates to maximal ketorolac plasma concentration or total exposure to ketorolac (AUC). Conclusion LIA provides good postoperative analgesia which is similar to femoral block after total knee arthroplasty. The plasma concentration of ropivacaine seems to be below toxic levels in most TKA patients. The unbound plasma concentration of ropivacaine in THA seems to be below the toxic level. Implication The use of ketorolac in LIA may not be safer than other routes of administration, and similar restrictions should be applied in patients at risk of developing side effects.

Background and aims The Visual Analogue Scale (VAS) is a popular tool for the measurement of pain. A variety of statistical methods are employed for its analysis as an outcome measure, not all of them optimal or appropriate. An issue which has attracted much discussion in the literature is whether VAS is at a ratio or ordinal level of measurement. This decision has an influence on the appropriate method of analysis. The aim of this article is to provide an overview of current practice in the analysis of VAS scores, to propose a method of analysis which avoids the shortcomings of more traditional approaches, and to provide best practice recommendations for the analysis of VAS scores. Methods We report on the current usage of statistical methods, which fall broadly into two categories: those that assume a probability distribution for VAS, and those that do not. We give an overview of these methods, and propose continuous ordinal regression, an extension of current ordinal regression methodology, which is appropriate for VAS at an ordinal level of measurement. We demonstrate the analysis of a published data set using a variety of methods, and use simulation to compare the power of the various methods to detect treatment differences, in differing pain situations. Results We demonstrate that continuous ordinal regression provides the most powerful statistical analysis under a variety of conditions. Conclusions and Implications We recommend that in the situation in which no covariates besides treatment group are included in the analysis, distribution-free methods (Wilcoxon, Mann–Whitney) be used, as their power is indistinguishable from that of the proposed method. In the situation in which there are covariates which affect VAS, the proposed method is optimal. However, in this case, if the VAS scores are not concentrated around either extreme of the scale, normal-distribution methods ( t -test, linear regression) are almost as powerful, and are recommended as a pragmatic choice. In the case of small sample size and VAS skewed to either extreme of the scale, the proposed method has vastly superior power to other methods.

Background and Aims Chronic pain is a potentially disabling condition affecting one in three people through impaired physical function and quality of life. While the psychosocial impact of chronic pain is already well established, little is known about the potential biological consequences. Chronic pain may be associated with an increased prevalence of cardiovascular disease, an effect that has been demonstrated across a spectrum of chronic pain conditions including low back pain, pelvic pain, neuropathic pain and fibromyalgia. The aim of this study was to review and summarize the evidence for a link between chronic pain and cardiovascular disease. We sought to clarify the nature of the relationship by examining the basis for a dose-response gradient (whereby increasing pain severity would result in greater cardiovascular disease), and by evaluating the extent to which potentially confounding variables may contribute to this association. Methods Major electronic databases MEDLINE, EMBASE, Psychinfo, Cochrane, ProQuest and Web of Science were searched for articles reporting strengths of association between chronic pain (pain in one or more body regions, present for three months or longer) and cardiovascular outcomes (cardiovascular mortality, cardiac disease, and cerebrovascular disease). Meta-analysis was used to pool data analysing the association between chronic pain and the three principal cardiovascular outcomes. The impact of pain severity, and the role of potentially confounding variables were explored narratively. Results The searches generated 11,141 studies, of which 25 matched our inclusion criteria and were included in the review. Meta-analysis (of unadjusted study outcomes) demonstrated statistically significant associations between chronic pain and mortality from cardiovascular diseases: pooled odds ratio 1.20, (95% confidence intervals 1.05–1.36); chronic pain and cardiac disease: pooled odds ratio 1.73 (95% confidence intervals 1.42–2.04); and chronic pain and cerebrovascular disease: pooled odds ratio 1.81 (95% confidence intervals 1.51–2.10). The systematic review also found evidence supporting a dose-response relationship, with greater pain intensity and distribution producing a stronger association with cardiovascular outcomes. All of the included studies were based on observational data with considerable variation in chronic pain taxonomy, methodology and study populations. The studies took an inconsistent and incomplete approach in their adjustment for potentially confounding variables, making it impossible to pool data after adjustments for confounding variables, so it cannot be concluded that these associations are causal. Conclusions Our review supports a possible dose-response type of association between chronic pain and cardiovascular disease, supported by a range of observational studies originating from different countries. Such research has so far failed to satisfactorily rule out that the association is due to confounding variables. What is now needed are further population based longitudinal studies that are designed to allow more robust exploration of a cause and effect relationship. Implications Given the high prevalence of chronic pain in developed and developing countries our results highlight a significant, but underpublicized, public health concern. Greater acknowledgement of the potentially harmful biological consequences of chronic pain may help to support regional, national and global initiatives aimed at reducing the burden of chronic pain.

Background Musculoskeletal pain in the distal upper limb is common and is a cause of disability and healthcare consultation. At the time of presentation individuals reporting similar pain severities may report different levels of related disability. The biopsychosocial model proposes that health beliefs may help explain this difference. The aim of this cross-sectional study was to identify underlying constructs of health belief in those referred to physiotherapy with pain in the distal upper limb and investigate whether these constructs moderated the relationship between pain severity and extent of disability. Method Health beliefs were assessed using an instrument included in a questionnaire completed before randomisation to the Arm Pain Trial (ISRCTN79085082). Ordinal responses to statements about health beliefs were used to generate a polychoric correlation matrix. The output from this matrix was then used for Exploratory Factor Analysis to determine underlying constructs. The moderating influence of the identified health belief constructs was then tested using interaction terms in linear regression models. Results 476 trial participants contributed data, age range 18–85 (mean 48.8, SD 13.7), 54% female. Five health belief constructs were identified: beliefs about hereditary factors, beliefs about movement and pain, beliefs about locus of control, beliefs about the role of lifecourse/lifestyle factors, and beliefs about prognosis. The only health belief construct found to moderate the pain-disability relationship was beliefs about prognosis, with greater pessimism resulting in higher levels of disability at mild-to-moderate levels of pain severity (B –0.17,95% CI –0.30, –0.036). Conclusion This exploratory cross-sectional study identified five constructs of health belief from responses to a previously used set of statements investigating fear avoidance and illness beliefs in a clinical population with pain in the distal upper limb. Of these constructs, beliefs about prognosis were found to moderate the relationship between pain and disability. Implications At the time of referral to physiotherapy it may be beneficial to assess patients’ perception of prognosis. For those with higher than expected disability for the presenting level of pain, and pessimism about prognosis, focused reassurance may play an important part in initial consultation. Longitudinal study is required to support the findings from this study and investigate whether a causal relationship exists. Future investigations should confirm the health belief constructs proposed.

Background and aim There is evidence that clinicians’ pain attitudes and beliefs are associated with the pain beliefs and illness perceptions of their patients and furthermore influence their recommendations for activity and work to patients with back pain. The Pain Attitudes and Beliefs Scale (PABS) is a questionnaire designed to differentiate between biomedical and biopsychosocial pain attitudes among health care providers regarding common low back pain. The original version had 36 items, and several shorter versions have been developed. Concern has been raised over the PABS’ internal construct validity because of low internal consistency and low explained variance. The aim of this study was to examine and improve the scale’s measurement properties and item performance. Methods A convenience sample of 667 Norwegian physiotherapists provided data for Rasch analysis. The biomedical and biopsychosocial subscales of the PABS were examined for unidimensionality, local response independency, invariance, response category function and targeting of persons and items. Reliability was measured with the person separation index (PSI). Items originally excluded by the developers of the scale because of skewness were re-introduced in a second analysis. Results Our analysis suggested that both subscales required removal of several psychometrically redundant and misfitting items to satisfy the requirements of the Rasch measurement model. Most biopsychosocial items needed revision of their scoring structure. Furthermore, we identified two items originally excluded because of skewness that improved the reliability of the subscales after reintroduction. The ultimate result was two strictly unidimensional subscales, each consisting of seven items, with invariant item ordering and free from any form of misfit. The unidimensionality implies that summation of items to valid total scores is justified. Transformation tables are provided to convert raw ordinal scores to unbiased interval-level scores. Both subscales were adequately targeted at the ability level of our physiotherapist population. Reliability of the biomedical subscale as measured with the PSI was 0.69. A low PSI of 0.64 for the biopsychosocial subscale indicated limitations with regard to its discriminative ability. Conclusions Rasch analysis produced an improved Norwegian version of the PABS which represents true (fundamental) measurement of clinicians’ biomedical and biopsychosocial treatment orientation. However, researchers should be aware of the low discriminative ability of the biopsychosocial subscale when analyzing differences and effect changes. Implications The study presents a revised PABS that provides interval-level measurement of clinicians’ pain beliefs. The revision allows for confident use of parametric statistical analysis. Further examination of discriminative validity is required.

Background Psychological factors are thought to impact headache as triggering, maintaining, and exacerbating factors. A better understanding of the role that modifiable factors, such as anxiety or depression, play in the impact of migraine could help identify potential treatment targets in this population. Objectives The objective of this study was to evaluate the relative importance of anxiety and depression as predictors of the impact of migraine on function. Thus, we aim to understand the relative importance that anxiety and depression have on the impact of migraines by assessing both and some life domains. Methods Cross-sectional study involving forty-three individuals, mostly females (93%), with migraine headaches aged between 20 and 60 years old. Participants answered questions about headache pain intensity at the time of data collection and the usual in the past 30 days (0–10 Numerical Rating Scales) as well as other pain characteristics (i.e., duration, frequency, and duration), headache impact (vitality and social, role, and cognitive functioning), anxiety and depression by using the Hospital Anxiety and Depression Scale. Results Anxiety ( r = 0.56, p < .001), but not depression ( r = 0.09, p = .59), was significantly associated with headache impact. Thus showing the relative importance that anxiety has on headache impact. Conclusions The findings support a larger role for anxiety than depression in the impact of migraine headaches on patient function. There are a number of mechanisms by which anxiety could potentially influence the impact of headache on patient function, and this study highlights that anxiety could potentially be a trigger of headache activity. Implications The findings thus suggest the possibility that treatments that focus on anxiety might be potentially more important for individuals with migraine than treatments that focus on depression, at least with respect to having a beneficial impact on the interference of headache with activity. Research is needed to evaluate the beneficial impact of anxiety treatment in individuals with migraine headaches. Clinicians should evaluate and consider treating, as appropriate and necessary, anxiety in patients with migraine.

Background and aims Currently there is a lack of large population studies that have investigated pain sensitivity distributions in healthy pain free people. The aims of this study were: (1) to provide sex-specific reference values of pressure and cold pain thresholds in young pain-free adults; (2) to examine the association of potential correlates of pain sensitivity with pain threshold values. Methods This study investigated sex specific pressure and cold pain threshold estimates for young pain free adults aged 21–24 years. A cross-sectional design was utilised using participants ( n =617) from the Western Australian Pregnancy Cohort (Raine) Study at the 22-year follow-up. The association of site, sex, height, weight, smoking, health related quality oflife, psychological measures and activity with pain threshold values was examined. Pressure pain threshold (lumbar spine, tibialis anterior, neck and dorsal wrist) and cold pain threshold (dorsal wrist) were assessed using standardised quantitative sensory testing protocols. Results Reference values for pressure pain threshold (four body sites) stratified by sex and site, and cold pain threshold (dorsal wrist) stratified by sex are provided. Statistically significant, independent correlates of increased pressure pain sensitivity measures were site (neck, dorsal wrist), sex (female), higher waist-hip ratio and poorer mental health. Statistically significant, independent correlates of increased cold pain sensitivity measures were, sex (female), poorer mental health and smoking. Conclusions These data provide the most comprehensive and robust sex specific reference values for pressure pain threshold specific to four body sites and cold pain threshold at the dorsal wrist for young adults aged 21–24 years. Establishing normative values in this young age group is important given that the transition from adolescence to adulthood is a critical temporal period during which trajectories for persistent pain can be established. Implications These data will provide an important research resource to enable more accurate profiling and interpretation of pain sensitivity in clinical pain disorders in young adults. The robust and comprehensive data can assist interpretation of future clinical pain studies and provide further insight into the complex associations of pain sensitivity that can be used in future research.

Background Treatment of neuropathic pain in children is challenging, and requires a multimodal approach of pharmacologic, physical, and psychological therapies; however there is little evidence to guide practice. Amitriptyline and gabapentin are first-line drugs for treating neuropathic pain in adults, yet no studies have examined their efficacy, or compared them directly, to determine which might be better for pain relief and sleep disturbance in children. Methods After informed consent was obtained, 34 patients aged 7–18 years diagnosed with complex regional pain syndrome type I (CRPS I) or a neuropathic pain condition were randomly allocated to receive either amitriptyline or gabapentin. Patients were followed for 6 weeks and assessed for pain intensity, sleep quality and adverse events. We blinded study personnel, including health-care providers, participants, parents, the research coordinator and the data analyst. Patients then completed quantitative sensory testing (QST) and a psychosocial pain assessment with the team psychologist, within 1–3 days of the start of the trial. Results At the end of the 6-week trial, patients on both drugs had important reductions in pain, having surpassed the minimally important difference (MID) of 1. The difference between the groups however was not statistically significant. For the secondary outcomes, we found no statistically significant difference between the two drugs in sleep score or adverse events suggesting that both drugs improve sleep score to a similar degree and are equally safe. Conclusions Amitriptyline and gabapentin significantly decreased pain intensity scores and improved sleep. There were no significant differences between the two drugs in their effects on pain reduction or sleep disability. Implications Although larger, multi-centred trials are needed to confirm our findings, including longterm follow-up, both drugs appear to be safe and effective in treating paediatric patients in the first-line treatment of CRPS I and neuropathic pain over 6-weeks.

Background and aims Fibromyalgia (FM) is a chronic, rheumatic disease characterized by widespread myofascial pain, of unknown aetiology, having a major impact on quality of life (QOL). Available pharmacotherapy for FM is marginally effective. FM is associated with co-morbidities of gastrointestinal (GI) disorders and Irritable Bowel Syndrome (IBS). There is growing evidence that diets low in FODMAPs, “fermentable oligo-, di- or mono-saccharides and polyols” [Low FODMAP Diet (LFD)], are effective in treating IBS. The aim of this pilot study was to examine the effects of LFDs on symptoms of FM, especially with regard to pain, QOL and GI disorders. Methods A longitudinal study using LFD intervention was performed on 38, 51±10 year-old, female patients diagnosed with FM for an average of 10 years, based on ACR (American College of Rheumatology) 2010 criteria. The study was conducted from January through May, 2015, using a four-week, repeated-assessment model, as follows: Moment 0 – introduction of the protocol to participants; Moment 1 – first assessment and delivery of individual LFD dietary plans; Moment 2 – second assessment and reintroduction of FODMAPs; Moment 3 – last assessment and final nutritional counselling. Assessment tools used were the following: RFIQ (Revised Fibromyalgia Impact Questionnaire), FSQ (Fibromyalgia Survey Questionnaire), IBS-SSS (Severity Score System), EQ-5D (Euro-QOL quality of life instrument), and VAS (Visual Analogue Scale). Daily consumption of FODMAPs was quantified based on published food content analyses. Statistical analyses included ANOVA, non-parametric Friedman, t -student and Chi-square tests, using SPSS 22 software. Results The mean scores of the 38 participants at the beginning of the study were: FSQ (severity of FM, 0–31) – 22±4.4; RFIQ (0–100) – 65±17; IBS-SSS (0–500) – 275± 101; and EQ-5D (0–100) – 48± 19. Mean adherence to dietary regimens was 86%, confirmed by significant difference in FODMAP intakes (25 g/day vs. 2.5 g/day; p < 0.01). Comparisons between the three moments of assessment showed significant ( p < 0.01) declines in scores in VAS, FSQ, and RFIQ scores, in all domains measured. An important improvement was observed with a reduction in the severity of GI symptoms, with 50% reduction in IBS scores to 138±117, following LFD therapy. A significant correlation ( r = 0.36; p < 0.05) was found between improvements in FM impact (declined scores) and gastrointestinal scores. There was also a significant correlation ( r = 0.65; p < 0.01) between “satisfaction with improvement” after introduction of LFDs and “diet adherence”, with satisfaction of the diet achieving 77% among participants. A significant difference was observed between patients who improved as compared to those that did not improve (Chi-square χ 2 = 6.16; p < .05), showing that the probability of improvement, depends on the severity of the RFIQ score. Conclusions Implementation of diet therapy involving FODMAP restrictions, in this cohort of FM patients, resulted in a significant reduction in GI disorders and FM symptoms, including pain scores. These results need to be extended in future larger studies on dietary therapy for treatment of FM. Implications According to current scientific knowledge, these are the first relevant results found in an intervention with LFD therapy in FM and must be reproduced looking for a future dietetic approach in FM.

Background This analysis evaluated whether osteoarthritis patients achieving the greatest pain control and lowest pain states also have the greatest improvement in functioning and quality of life. Methods Patients ( n = 419) who failed prior therapies and who were switched to etoricoxib 60 mg were categorized as pain responders or non-responders at 4 weeks based on responder definitions established by the Initiative on Methods, Measurement, and Pain (IMMPACT) criteria, including changes from baseline of ≥15%, ≥30%, ≥50%, ≥70% and a final pain status of ≤3/10 (no worse than mild pain). Pain was assessed at baseline and 4 weeks using 4 questions from the Brief Pain Inventory (BPI) (worst pain, least pain, average pain, and pain right now), and also using the Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain subscale. We examined the relationship between pain responses with changes from baseline in two functional measures (the BPI Pain Interference questions and the WOMAC Function Subscale) as well as changes from baseline in quality of life (assessed on the SF-36 Physical and Mental Component Summaries). We also sought to understand whether these relationships were influenced by the choice of the pain instrument used to assess response. We contrast the mean difference in improvements in the functional and quality of life instruments based on pain responder status (responder versus non-responder) and the associated 95% confidence limits around this difference. Results Patients with better pain responses were much more likely to have improved functional responses and improved quality of life, with higher mean changes in these outcomes versus pain nonresponders, regardless of the choice of IMMPACT pain response definition (e.g., using any of 15%, 30%, 50%, 70% change from baseline) or the final pain state of ≤3/10. There was an evident gradient, where higher levels of pain response were associated with greater mean improvements in function and quality of life. The finding that greater pain responses led to greater functional improvements and quality of life gains was not dependent on the manner in which pain was evaluated. Five different pain instruments (e.g., the 4 questions on pain from the BPI pain questionnaire and the WOMAC pain subscale) consistently demonstrated that pain responders had statistically significantly greater improvements in function and quality of life compared to pain non-responders. This suggests these results are likely to be generalizable to any validated pain measure for osteoarthritis. Conclusions Pain is an efficient outcome measure for predicting broader patient response in osteoarthritis. Patients who do not achieve timely, acceptable pain states over 4 weeks were less likely to experience functional or quality of life improvements. Implications Good pain improvements in osteoarthritis with a valid pain instrument are a proxy for good improvements in both function and quality of life. Therefore proper osteoarthritis pain assessment can lead to efficient evaluations in the clinic.

Introduction Chronic pain causes suffering for affected individuals and incurs costs to society through work disability. Interventions based on early screening of psychological risk factors for chronic pain using screening tools such as the Örebro Musculoskeletal Pain Screening Questionnaire (ÖMPSQ) have been found to reduce work absenteeism and health care visits and increase perceived health. The aim of the current study was to translate the ÖMPSQ into Finnish and test its validity and reliability in a patient sample. Methods The ÖMPSQ was forward–backward translated and cross-culturally adapted, and applied to our study population ( n = 69), the members of which had been referred to the Department of Physical and Rehabilitation Medicine of Oulu University Hospital from primary health care centres in Northern Finland due to chronic low back pain. The patients answered the ÖMPSQ two weeks before the hospital visit, and the follow-up questionnaire either during the hospital visit, or after by mail. The reliability of the ÖMPSQ was evaluated using intraclass correlation coefficients (ICC). Factor analysis was used to group items of the ÖMPSQ, and internal consistency between the items was determined by calculating Cronbach’s alphas. Results The cross-cultural adaptation revealed only minor semantic and cultural differences. Measurements showed reliability as moderate to nearly perfect for all of the ÖMPSQ items (ICC values ranged from 0.59 to 0.96). Items loaded into five different factors: disability, psychological symptoms, pain, fear avoidance, and work. All except one (work) showed acceptable internal consistency. The ÖMPSQ score was positively associated with both intensity of pain and the Oswestry Disability Index. Conclusions and implications The reliability and construct validity of the Finnish version of the ÖMPSQ were good. The predictive ability of the ÖMPSQ in the Finnish population should be evaluated in further studies.

Background and aims A substantial portion of the population suffers from chronic pain leading to significant health care costs and lost productivity. Loss of sleep duration and quality are widely reported in patients suffering from a variety of acute orchronicpain conditions. Conversely, sleep loss has been known to elevate pain perception; thus a potential bi-directional relationship exists between sleep deprivation and pain. To date, the majority of studies examining the relationship between experimentally induced pain and sleep loss have focused on the measurement of pain threshold . Additionally, despite evidence of sex differences in ratings of perceived pain, previous studies examining pain following sleep loss have not probed for sex differences. We examined the effects of 24-h total sleep deprivation (TSD) on perceived pain during a 2-min cold pressor test (CPT). We hypothesized that TSD would augment perceived pain and that women would demonstrate an elevated pain response compared to men. Methods Testing was carried out in 14 men and 13 women. All subjects reported to be nonsmokers with no history of cardiovascular disease, autonomic dysfunction, asthma, or diabetes. All female subjects were free of oral contraceptive use, and were tested during the early follicular phase of the menstrual cycle. Trial order was randomized and testing sessions (Normal sleep (NS) and TSD) were separated by approximately one month. Subjects immersed their left hand, up to the wrist, in an ice water bath (∼1° C), and perceived pain was recorded every 15 s from a modified Borg scale (6–20 arbitrary units a.u.). Results Perceived pain responses during CPT were augmented following TSD (Δ 1.2 a.u.; time × condition, p < 0.05). The augmented pain response following TSD was noted when perceived pain was expressed as mean (NS Δ 7.0 ± 0.5 vs. TSD Δ 8.2 ± 0.5 a.u.; p < 0.05) or peak (NS Δ 8.9 ± 0.6 vs. TSD Δ 10.2 ± 0.5 a.u.; p < 0.05) perceived pain. The effects of TSD on perceived pain were similar in both men and women (condition × time × sex, p > 0.05). Conclusions and implications We conclude that TSD significantly augments perceived pain during CPT, but this response was not sex dependent. These findings support emerging evidence that adequate sleep represents a relevant, and cost effective, preventative/therapeutic strategy to reduce self-perceived pain in both men and women.