Home Osteoarthritis patients with pain improvement are highly likely to also have improved quality of life and functioning. A post hoc analysis of a clinical trial
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Osteoarthritis patients with pain improvement are highly likely to also have improved quality of life and functioning. A post hoc analysis of a clinical trial

  • Paul M. Peloso , R. Andrew Moore , Wen-Jer Chen , Hsiao-Yi Lin , Davis F. Gates , Walter L. Straus and Zoran Popmihajlov EMAIL logo
Published/Copyright: October 1, 2016
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Scandinavian Journal of Pain
From the journal Scandinavian Journal of Pain Volume 13 Issue 1

Abstract

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.

Keywords: Osteoarthritis; Pain; Patient-reported outcome; Function; Quality of life

1 Introduction

Pain and stiffness are the main concerns of patients with osteoarthritis, with pain reduction and improved functioning as major treatment goals [1]. There are two competing views on understanding response in osteoarthritis patients. Some argue that since pain is primary, the treatment should be targeted towards moderate to substantial pain reductions [2, 3]. Others maintain that response in osteoarthritis is multifactorial, making it necessary to consider several outcomes such as pain, function, and patient global assessment [4]. If response could be assessed with a single pain question that was known to reflect improvements in function and quality of life, it would simplify the clinical management of osteoarthritis.

Mean responses in a clinical trial setting do not translate well to individual patients in the clinic. Patients are not ‘average’, which may explain why many patients do not achieve the pain relief they desire [3]. The use of average response from clinical trials may also address why real-world pain treatment decisions lack clear guideposts [5, 6]. Clinical trial evidence translation issues exist not only for pain, but across many patient-reported outcomes measures [7]. Research in low back pain for instance, has shown that a single recall rating of average pain over 24h demonstrated treatment effects as well as a composite score taken from nine pain ratings [8], suggesting simplicity is achievable.

Clinically meaningful pain response has been defined by the IMMPACT Group [9]; minimal improvement is defined as 15% change from baseline, moderate improvement is defined as 30% change from baseline, and substantial improvement is defined as 50% change from baseline [10]. Achieving a symptom state acceptable to patients was codified in the quote attributed to Professor Maxime Dougados, “It is good to feel better, but it is better to feel good.” The Patient Acceptable Symptom State defines a pain state that is acceptable to patients for an extended period of time, and values from 32.0 to 35.0 out of 100 represent acceptable state for osteoarthritis patients. [7]. Recently Moore et al. advocated for adopting a simple “no worse than mild pain” outcome, defined as pain ≤3/10 as a straightforward, universal treatment target. [11]. The comprehensive review by Moore and colleagues showed that the final state of pain ≤3/10 is preferred by both acute and chronic pain patients, is associated with greater levels of satisfaction with treatment, and once achieved tends to be stable over time and also lead to less rescue medication use.

Evidence from painful non-osteoarthritis conditions suggests that well-controlled pain has benefits on quality of life, functional, and associated economic benefits. [2, 12, 13, 14]. Conversely, inadequate pain relief has been shown to predict patient preference for total knee replacement [15].

This secondary analysis tested the hypothesis that patients with osteoarthritis who experienced the greatest improvement in pain would also experience the greatest improvements in function and quality of life [16]. The relationship between pain improvements and improvements in function on the WOMAC function subscale and the BPI pain interference instrument as well as improvements in quality of life on the SF-36 was also evaluated. We extended these relationships to consider: (1) whether there was a response gradient for function and quality of life improvements when increasingly stricter definitions of pain response were used, ≥15%, 30%, 50% and 70% improvement from baseline or a final pain state of ≤3/10; and (2) whether the choice of pain questions influenced the relationship between pain improvements and function and quality of life gains.

2 Methods

2.1 Study design and patient population

A secondary analysis was conducted using data from a multicenter, prospective, open-label single-arm study of etoricoxib in patients (n = 500) with osteoarthritis who had inadequate pain relief with prior treatments [16]. The patient population included 419 patients who completed the questionnaire at baseline and week 4. The study was conducted in 16 hospitals in Taiwan from November 15, 2007 to December 2, 2008. The study protocol and procedures were approved by the respective Ethics Review Boards. Men and women 20 years or older with a confirmed diagnosis of osteoarthritis of the knee or hip requiring symptomatic treatment were eligible. Patients were required to have been taking a nonsteroidal anti-inflammatory, cyclooxygenase-2 inhibitor, or an opioid on the majority of days during the 4 weeks prior to enrollment, but having either: (1) inadequate pain relief on current therapy, defined as physician-rated pain score ≥40 mm on a 100 mm visual analog scale (VAS); or (2) intolerance to their current treatment due to gastrointestinal events. Exclusion criteria for the study included: current gastrointestinal ulcer with active bleeding; history of stroke, myocardial infarction or transient ischemic attack within the previous 2 years; advanced renal insufficiency (calculated creatinine clearance <30 mL/min); active hepatic disease (Child-Pugh score >9). Eligible patients were switched from their existing analgesic medication (without an intervening washout period) to open-label etoricoxib 60 mg daily for 4 weeks.

To assess functional improvement, the WOMAC function subscale (a summary of 17 individual items) and the Pain Interference questions on the BPI were used. The BPI Pain Interference questions include 7 items assessing work, walking, general activities, mood, sleep, relations with others, and enjoyment of life with each item considered separately [17, 18, 19, 20]. The SF-36 was summarized into Physical Component Summary (PCS) and the Mental Component Summary (MCS) scales, reflecting physical and mental elements of quality of life, respectively.

We explored whether a gradient for pain improvement with functional and quality of life gains existed (i.e. higher pain responses had greater improvements in function and quality of life), by using different levels of pain improvement as ≥15%, ≥30%, ≥50%, ≥70% change from baseline; or achievement of a final pain state of ≤3/10 (also known as “no worse than mild pain”).

Our analysis considered five different pain instruments validated in osteoarthritis; four pain questions from the Brief Pain Inventory (BPI) that address “worst pain, least pain, average pain, and pain right now” on a 0–10 numerical rating scale and the WOMAC pain subscale. The WOMAC pain subscale incorporates five questions about osteoarthritis pain, which are summarized as a single score.

2.2 Statistical analysis

Participants were identified as responders or non-responders based on pain response from baseline to week 4 using different thresholds described above. The four pain questions on the BPI were used as reported on the 0–10 numerical rating scale. The 5 questions comprising the WOMAC pain subscale were each scored from 0 to 100 and then summed into a single score [17]. This score from 0–500 was transformed to a 0–10 format to facilitate comparisons with the four BPI pain questions. Analysis of covariance was performed based on whether the patient was a pain responder or a non-responder, and the relationship of pain response to the changes on other health status outcomes was assessed.

Function was assessed by the WOMAC function subscale scores calculated as a sum of 17 questions each scored from 0 to 100. This summed score varied between 0–1700 and was divided by 17 and reported on a 0–100 scale. Function was also assessed across each of the 7 items on the BPI Pain Interference questions individually. Quality of life was evaluated by the SF-36 PCS (physical) and SF-36 MCS (mental) as subscale measures. The mean change from baseline in function or quality of life was contrasted for pain responders versus pain non-responders. The difference in means between responders and non-responders is presented along with the 95% confidence limits around this difference.

3 Results

Patients (n = 500) considered for this analysis were predominantly women (73%) with osteoarthritis of the knee (93.2%), and a mean age of 67 years (Table 1). Patients enrolled in the trial had received an average of 23±9.4 days of analgesic therapy prior to randomization; celecoxib, meloxicam, acetaminophen, and diclofenac were the most commonly used. Of these 500 patients, 419 (84%) completed the 4 weeks and contributed to this analysis. The most common reasons for discontinuation included withdrawal of consent (n = 37), lost to follow-up (n = 19), adverse event (n = 15) and lack of efficacy (n = 10) (16).

Table 1

Patient characteristics.[a]

Characteristic (n = 500) Mean ± SD or %
Female 73%
Age (years) 66.6 ± 10
Weight (kg) 64.8 ± 10.6
Body mass index (kg/m2) 26.1 ± 3.7
Co-morbidities
 None 28.2%
 Hypertension 39.1%
 Osteoporosis 20.0%
 Diabetes 10.7%
 Peptic ulcer 6.3%
 Cardiovascular disease 2.8%
Primary osteoarthritis location
 Knee 93.2%
 Hip 1.8%
 Spine 3.8%
 Hand 0.8%
Prior analgesic used (>1%)
 Celecoxib 20.6%
 Meloxicam 16.4%
 Acetaminophen 12.6%
 Diclofenac 11.6%
 Etodolac 7.2%
 Ultracet 5.8%
 Tiaprofenic acid 2.8%
 Naproxen 1.4%
 Nabumetone 1.0%
Baseline Pain Scores
 WOMAC pain (mean &(SD))/100 38.5 (22.9)
 BPI pain right now (mean)/10 4.4
 BPI worst pain (mean)/10 6.4
 BPI least pain (mean)/10 3.2
 BPI average pain (mean)/10 4.9

Fig. 1 shows the relationship between the BPI Average Pain responder status against the SF-36 PCS and MCS subscales and the WOMAC Function Subscale, across different definitions of pain responders. Fig. 2 shows the relationship between WOMAC pain responder status and the WOMAC function subscale, using different definitions of pain responders. Collectively Figs. 1 and 2 show that differences in the least squares mean change in function and quality of life were greater for pain responders versus pain nonresponders. They also confirm a response gradient, where in deeper levels of pain response were also associated with greater gains in function and quality of life. Pain responders with improvements of ≥70% from baseline had the largest function and quality of life gains. The difference in means for function and quality of life were highly statistically significant (p-values <0.001) when comparing pain responders to non-responders.

Fig. 1 Effect of different BPI pain response definitions on SF-36 PCS, SF-36 MCS, and WOMAC function. A comparison of the influence of different pain response definitions using BPI average pain questions across several pain response definition cut-points of ≥15%, ≥30%, ≥50%, ≥70% change from baseline and final pain state ≤3/10 across quality of life and function outcomes. (A) SF-36 physical function component score (SF-36 PCS), (B) SF-36 mental function component score (SF-36 MCS), and (C) WOMAC function.
Fig. 1

Effect of different BPI pain response definitions on SF-36 PCS, SF-36 MCS, and WOMAC function. A comparison of the influence of different pain response definitions using BPI average pain questions across several pain response definition cut-points of ≥15%, ≥30%, ≥50%, ≥70% change from baseline and final pain state ≤3/10 across quality of life and function outcomes. (A) SF-36 physical function component score (SF-36 PCS), (B) SF-36 mental function component score (SF-36 MCS), and (C) WOMAC function.

Fig. 2 Effect ofdifferent WOMAC pain response definitions on SF-36 PCS, SF-36 MCS, and WOMAC function. A comparison of the influence of different pain response definition cut-points using the WOMAC Pain Subscale for pain response definitions of ≥15%, ≥30%, ≥50%, ≥70% change from baseline and final pain ≤3/10 across quality of life and function: (A) SF-36 physical function component score (SF-36 PCS), (B) SF-36 mental function component score (SF-36 MCS), and (C) WOMAC function.
Fig. 2

Effect ofdifferent WOMAC pain response definitions on SF-36 PCS, SF-36 MCS, and WOMAC function. A comparison of the influence of different pain response definition cut-points using the WOMAC Pain Subscale for pain response definitions of ≥15%, ≥30%, ≥50%, ≥70% change from baseline and final pain ≤3/10 across quality of life and function: (A) SF-36 physical function component score (SF-36 PCS), (B) SF-36 mental function component score (SF-36 MCS), and (C) WOMAC function.

Fig. 3 further explored the influence of the 5 different methods to assess pain response, using with the WOMAC pain subscale and the four BPI pain measures (worst pain, least pain, average pain and pain right now). To simplify this presentation, pain responders were defined as a 50% change from baseline only and the mean differences (95% CI) between responders and non-responders are shown plotted against the seven BPI pain interference measures. Across all BPI interference assessments, pain responders had greater gains than non-responders, with 95% CI around this difference excluding zero. These findings held for different pain response definitions, beyond the 50% improvement from baseline and final pain ≦3/10 that are shown in Table 2.

Table 2

All BPI pain questions showed larger pain responses were accompanied by greater function and quality of life gains. Sub-legend: The influence of BPI pain questions (average pain, worst pain, least pain and pain right now) showed the same trend for quality of life and function using the SF-36 PCS, SF-36 MCS and WOMAC function with pain response cut-points of ≥50% and ≤3/10.

BPI pain question and cut-point SF-36 Physical Component Scale SF-36 Mental Component Scale WOMAC Function
Responder Non-responder Difference (95% CI) Responder Non-responder Difference (95% CI) Responder Non-responder Difference (95% CI)
Pain response as ≥50%
BPI worst pain ≥50% (n = 98)[a] 19.7 (n = 316)[a] 6.0 13.7 (10.0, 17.4) (n = 98) 14.4 (n = 316) 3.9 10.5 (7.1, 13.9) (n = 98) 19.0 (n = 313) 4.7 14.3 (10.5, 18.2)
BPI least pain ≥50% (n = 139) 18.5 (n = 239) 4.1 14.4 (11.1, 17.7) (n = 139) 12.8 (n = 239) 2.8 10.1 (7.0, 13.2) (n = 138) 16.3 (n = 237) 3.4 12.9 (9.5, 16.3)
BPI average pain ≥50% (n = 101) 20.5 (n = 311) 5.7 14.8 (11.2, 18.4) (n = 101) 15.2 (n = 311) 3.7 11.5 (8.1, 14.8) (n = 101) 18.5 (n = 308) 4.8 13.7 (9.9, 17.5)
BPI pain right now ≥50% (n = 163) 16.3 (n = 228) 3.7 12.6 (9.4, 15.9) (n = 163) 12.1 (n = 228) 2.2 9.9 (6.9, 12.9) (n = 162) 16.1 (n = 226) 2.1 14.0 (10.5, 17.4)
Pain response as ≤3/10
BPI worst pain ≤3/10 (n = 121) 18.9 (n = 297) 5.1 13.8 (10.3, 17.3) (n = 121) 13.6 (n = 297) 3.1 10.5 (7.3, 13.8) (n = 121) 17.5 (n = 294) 4.1 13.3 (9.6, 17.1)
BPI least pain ≤3/10 (n = 301) 12.9 (n = 117) −0.6 13.5 (10.0, 17.1) (n = 301) 9.4 (n = 117) −2.1 11.5 (8.2, 14.7) (n = 300) 11.4 (n = 115) −1.0 12.4 (8.5, 16.2)
BPI average pain ≤3/10 (n = 193) 17.0 (n = 226) 2.5 14.5 (11.4, 17.6) (n = 193) 11.8 (n = 226) 1.4 10.4 (7.5, 13.3) (n = 193) 16.2 (n = 223) 0.9 15.4 (12.0, 18.7)
BPI pain right now ≤3/10 (n = 249) 14.9 (n = 167) 0.5 14.4 (11.2, 17.6) (n = 249) 10.4 (n = 167) −0.4 10.8 (7.8, 13.7) (n = 248) 15.0 (n = 165) −2.6 17.5 (14.1, 20.9)

  1. The BPI short form was used for this study and questions 3 through 6 (worst pain, least pain, average pain and pain right now) were used in this analysis.

    BPI Q3, worst pain assessed as “Please rate your pain by circling the one number that best describes your pain at its worst in the last week.”

    BPI Q4, least pain assessed as “Please rate your pain by circling the one number that best describes your pain at its least in the last week.”

    BPI Q5, average Pain assessed as “Please rate your pain by circling the one number that best describes your pain on the average.”

    BPI Q6, pain right now assessed as “Please rate your pain by circling the one number that tells how much pain you have right now.”

Fig. 3 Influence of the choice of pain questionnaire on the seven BPI pain interference items. A comparison of the influence of different pain questionnaires (WOMAC pain, BPI worst pain, BPI least pain, BPI average pain and BPI pain right now) using a responder cut-point definition of ≥50% change from baseline across the seven BPI pain interference questions related to enjoyment of life, relationships with others, sleep, mood, general activity, walking ability and work.
Fig. 3

Influence of the choice of pain questionnaire on the seven BPI pain interference items. A comparison of the influence of different pain questionnaires (WOMAC pain, BPI worst pain, BPI least pain, BPI average pain and BPI pain right now) using a responder cut-point definition of ≥50% change from baseline across the seven BPI pain interference questions related to enjoyment of life, relationships with others, sleep, mood, general activity, walking ability and work.

Fig. 3 suggests that items directed towards physical abilities (e.g., walking, general activity and work outside the house) appeared to show greater improvements function and quality of life with pain response as compared to items directed more towards mood (e.g., relations with others, mood, and enjoyment of life), since there appears to be a trend towards larger improvements for items assessing physical function. However the 95% confidence intervals around the differences in means for responders and nonresponders were largely overlapping for all 7 BPI interference items and this should not be over-interpreted.

Of related interest, Table 2 suggests the largest differences between pain responders and non-responders are for WOMAC function, followed by SF-36 Physical Component Score followed by the SF-36 Mental Component Score suggesting functional outcomes may be more sensitive to improvements in pain than those directed to mental health. Importantly all measures of function and quality of life showed that higher levels of pain responses were accompanied by greater gains in function or quality of life. Significant correlations (p <0.0001) were observed between the individual magnitude of pain response and function and quality of life endpoints (not shown) and there was a response gradient for higher levels of pain response leading to greater gains in function and quality of life.

4 Discussion

In this analysis of patients with osteoarthritis, better pain response was associated with better function and quality of life outcomes. This finding was robust as this relationship was true across all definitions of pain response tested (e.g., ≥15%, ≥30%, ≥50%, and ≥70% change from baseline and final pain state as pain ≤3/10) as well as across all function and quality of life measures. There was evidence of a pain response gradient, with higher levels of pain response leading to greater function and quality of life gains. Collectively, these observations confirm our hypothesis that patients with osteoarthritis who have the greatest improvement in pain response also get the largest gains in function and quality of life.

While there was a trend for physical function related outcomes to improve more than mental health related outcomes, our analyses did not show that physical and mental outcomes were statistically different.

This analysis also showed that 5 valid osteoarthritis pain instruments; the WOMAC pain subscale and 4 pain questions from the BPI (i.e., worst pain, least pain, average pain, and pain right now) all led to the same conclusions. Regardless of the pain assessment, responders had the greatest gains in function and quality of life and higher levels of pain response had greater gains, suggesting our results are likely generalizable across all valid pain measures in osteoarthritis.

Studies in rheumatoid arthritis [21] and fibromyalgia [2] are consistent with our findings that good pain control tracks with improvement in other health outcomes. Conversely, inadequate pain relief was found to be both common among adults with knee osteoarthritis, and associated with worse quality of life and functional outcomes [22]. A systematic review of 13 studies of pain conditions other than osteoarthritis concluded that improvements in pain were correlated with improvement in at least one other important quality of life or functional improvement [23]. Our study extends these observations to osteoarthritis and adds to the literature by demonstrating that this relationship holds for functional assessments as well as physical and mental aspects of quality of life. We also show that higher levels of pain response are associated with greater gains in functional and quality of life. Further we show that this relationship holds true across 5 validated osteoarthritis pain measures.

It is important to note this study’s limitations. The data were taken from a single trial in a single country, although it was a multicenter study. This was not a placebo-controlled trial, so we cannot estimate how much of the improvements in quality of life and function may have been related to placebo responses. However, etoricoxib 60 mg has been well established to separate from placebo very efficiently in osteoarthritis, performing similarly to other nonsteroidal anti-inflammatories such as naproxen and better than agents such as acetaminophen [6, 24]. The instruments used (e.g., WOMAC function, BPI pain interference, SF36) may or may not be fully representative of any individuals’ key osteoarthritis limitations or goals for therapy [25]. A single pain question may not capture all of the components of response important to an individual patient, but pain is usually the single most important issue. Only day 0 and week 4 data were considered even though it is recognized that osteoarthritis is a chronic condition. Muscle weakness, joint instability and difficulties with proprioception that contribute to perpetuation of pain were not tested; such conditions may require physical therapist-based therapies to maximize the functional benefit from medicinal therapies. In our analyses, mean responses were grouped by responder status, a post-randomization covariate which some might suggest is not optimal for inferential testing (i.e., computation of p-values). However, if it is assumed that the subjects were predisposed to their respective responder status prior to randomization, the validity of descriptive analysis (i.e., 95% confidence intervals of response status differences) is sufficient to support our conclusions.

Pain response in osteoarthritis tracks with broader positive outcomes in function and quality of life. Pain assessment is a simple, efficient outcome for understanding patient response in osteoarthritis and could simplify discussions in the clinic. Based on these results, patients without moderate or substantial pain reduction by 4 weeks are unlikely to experience meaningful benefits in function or quality of life and should discontinue treatment in favor of alternate therapies that may provide better health outcomes.

Highlights

  • Better functional responses were more likely in patients with better pain response.

  • Better QoL improvements were more likely in patients with better pain response.

  • 5 pain measures consistently showed that better pain response lead to better health.

  • Pain assessment is a simple, efficient outcome for predicting OA patient responses.

DOI of refers to article: http://dx.doi.org/10.1016/j.sjpain.2016.09.003.

Merck & Co., Inc., RY34-A470, Rahway, NJ 07065, USA. Tel.: +1 732 594 4551; fax: +1 732 594 3178.

  1. Disclosures: This work was supported by Merck & Co., Inc., Kenilworth, NJ, USA.

  2. Conflict of interest: Relationships relevant to this manuscript: P.M. Peloso, D. F. Gates, W. L. Straus, Z. Popmihajlov are currently or were employees of Merck & Co., Inc. and may own stock/stock options in Merck & Co., Inc. W-J Chen, H-Y Lin were investigators for the study, which was sponsored by Merck & Co., Inc. R.A. Moore has no competing interests related to this work.

  3. Author contributions: All authors discussed the results and commented on the results and manuscript. P.M. Peloso, W-J Chen, H-Y Lin, D.F. Gates, W.L. Straus, Z. Popmihajlov and R.A. Moore made substantial contributions to: (1) study conception and design and analysis and interpretation of data; (2) drafting the article and revising it critically for important intellectual content; and (3) final approval of the version to be published.

  4. Ethical issues: The study was conducted in 16 hospitals in Taiwan and the protocol was not registered. The study protocol and procedures were approved by the respective Ethics Review Boards. Written consent was obtained prior to subjects undergoing any study procedures (16).

Acknowledgments

Wendy Horn, PhD, provided editorial assistance that was supported by Merck & Co., Inc., Kenilworth, NJ, USA.

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Abbreviations

BPI

Brief Pain Inventory

IMMPACT

Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials

OMERACT-OARSI

Outcomes Measures in Osteoarthritis and Osteoarthritis Research Society International

PCS

Physical Component Summary

MCS

Mental Component Summary

SF-36

Short Form (36)

WOMAC

Western Ontario and McMaster Universities Arthritis Index
Received: 2015-12-15
Revised: 2016-07-20
Accepted: 2016-07-21
Published Online: 2016-10-01
Published in Print: 2016-10-01

© 2016 Scandinavian Association for the Study of Pain

Articles in the same Issue

  2. Scandinavian Journal of Pain
  3. Editorial comment
  4. Increased deep pain sensitivity in persistent musculoskeletal pain but not in other musculoskeletal pain states
  5. Clinical pain research
  6. Increased deep pain sensitivity in persistent musculoskeletal pain but not in other musculoskeletal pain states
  7. Editorial comment
  8. Patient Reported Outcomes (PROs) are sensitive outcome-variables in patients with chronic pain: Importance of self-efficacy
  9. Observational study
  10. Using patient reported outcomes in oncology clinical practice
  11. Editorial comment
  12. Cortical reorganization of the healthy hand in upper-limb complex regional pain syndrome(CRPS): Is reorganizations of common beliefs about CRPS necessary?
  13. Original experimental
  14. An exploration into the cortical reorganisation of the healthy hand inupper-limb complex regional pain syndrome
  15. Editorial comment
  16. Is there hope for the most complicated chronic pain patients facing back surgery?
  17. Educational case report
  18. A preoperative interdisciplinary biopsychosocial opioid reduction program in patients on chronic opioid analgesia prior to spine surgery: A preliminary report and case series
  19. Editorial comment
  20. Pain management in the Emergency Department – Still a long way to go?
  21. Clinical pain research
  22. Mandatory documentation of pain in the emergency department increases analgesic administration but does not improve patients’ satisfaction of pain management
  23. Editorial comment
  24. Pain relief during childbirth: Efficacy and safety of prolonging labour-analgesia with morphine directly into the lumbar cerebro-spinal-fluid (CSF)
  25. Systematic review
  26. Prolonging the duration of single-shot intrathecal labour analgesia with morphine: A systematic review
  27. Editorial comment
  28. The intricate relationship amongst pain intensity, fear and avoidance
  29. Systematic review
  30. A meta-analysis of fear-avoidance and pain intensity: The paradox of chronic pain
  31. Editorial comment
  32. Local infiltration analgesia(LIA), risk of local anaesthetic systemic toxicity (LAST) and kidney failure from NSAID in elderly patients
  33. Topical review
  34. Local infiltration analgesia in knee and hip arthroplasty efficacy and safety
  35. Editorial comment
  36. Analysis of pain-intensity measurements
  37. Topical review
  38. How to analyze the Visual Analogue Scale: Myths, truths and clinical relevance
  39. Editorial comment
  40. The relationship between chronic pain and cardiovascular disease: Squaring the circle?
  41. Systematic review
  42. Assessing the relationship between chronic pain and cardiovasculardisease: A systematic review and meta-analysis
  43. Editorial comment
  44. Optimists fare better when chronic pain strikes – Or does pain related disability make us pessimists?
  45. Observational study
  46. Constructs of health belief and disabling distal upper limb pain
  47. Editorial comment
  48. Attitude and belief of pain-therapists are important when trying to help chronic pain patients: The Norwegian version of the Pain Attitudes and Beliefs Scale (PABS) improved by Rasch analysis
  49. Observational study
  50. Rasch analysis resulted in an improved Norwegian version of the Pain Attitudes and Beliefs Scale(PABS)
  51. Editorial comment
  52. Anxiety could play a larger role than depression in migraine headache
  53. Clinical pain research
  54. The relative importance of anxiety and depression in pain impact in individuals with migraine headaches
  55. Editorial comment
  56. Bringing the lab to the people: Experimental pain testing in the general population
  57. Clinical pain research
  58. Pressure and cold pain threshold reference values in a large, young adult, pain-free population
  59. Editorial comment
  60. Improving pain treatment in children
  61. Clinical pain research
  62. A randomized controlled trial of amitriptyline versus gabapentin for complex regional pain syndrome type I and neuropathic pain in children
  63. Editorial comment
  64. Gut gateway to generalized pain
  65. Original experimental
  66. A low fermentable oligo-di-mono saccharides and polyols(FODMAP) diet reduced pain and improve ddaily life in fibromyalgia patients
  67. Editorial comment
  68. Measuring outcomes of pain management
  69. Clinical pain research
  70. Osteoarthritis patients with pain improvement are highly likely to also have improved quality of life and functioning. A post hoc analysis of a clinical trial
  71. Clinical pain research
  72. Construct validity and reliability of Finnish version of Örebro Musculoskeletal Pain Screening Questionnaire
  73. Observational study
  74. Total sleep deprivation and pain perception during cold noxious stimuli in humans
  75. Corrigendum
  76. Corrigendum to ‘Reliability of pressure pain threshold testing in healthy pain free young adults’ [Scand. J. Pain 9 (2015) 38–41]
https://doi.org/10.1016/j.sjpain.2016.07.002
Keywords for this article
Osteoarthritis; Pain; Patient-reported outcome; Function; Quality of life

Articles in the same Issue

  2. Scandinavian Journal of Pain
  3. Editorial comment
  4. Increased deep pain sensitivity in persistent musculoskeletal pain but not in other musculoskeletal pain states
  5. Clinical pain research
  6. Increased deep pain sensitivity in persistent musculoskeletal pain but not in other musculoskeletal pain states
  7. Editorial comment
  8. Patient Reported Outcomes (PROs) are sensitive outcome-variables in patients with chronic pain: Importance of self-efficacy
  9. Observational study
  10. Using patient reported outcomes in oncology clinical practice
  11. Editorial comment
  12. Cortical reorganization of the healthy hand in upper-limb complex regional pain syndrome(CRPS): Is reorganizations of common beliefs about CRPS necessary?
  13. Original experimental
  14. An exploration into the cortical reorganisation of the healthy hand inupper-limb complex regional pain syndrome
  15. Editorial comment
  16. Is there hope for the most complicated chronic pain patients facing back surgery?
  17. Educational case report
  18. A preoperative interdisciplinary biopsychosocial opioid reduction program in patients on chronic opioid analgesia prior to spine surgery: A preliminary report and case series
  19. Editorial comment
  20. Pain management in the Emergency Department – Still a long way to go?
  21. Clinical pain research
  22. Mandatory documentation of pain in the emergency department increases analgesic administration but does not improve patients’ satisfaction of pain management
  23. Editorial comment
  24. Pain relief during childbirth: Efficacy and safety of prolonging labour-analgesia with morphine directly into the lumbar cerebro-spinal-fluid (CSF)
  25. Systematic review
  26. Prolonging the duration of single-shot intrathecal labour analgesia with morphine: A systematic review
  27. Editorial comment
  28. The intricate relationship amongst pain intensity, fear and avoidance
  29. Systematic review
  30. A meta-analysis of fear-avoidance and pain intensity: The paradox of chronic pain
  31. Editorial comment
  32. Local infiltration analgesia(LIA), risk of local anaesthetic systemic toxicity (LAST) and kidney failure from NSAID in elderly patients
  33. Topical review
  34. Local infiltration analgesia in knee and hip arthroplasty efficacy and safety
  35. Editorial comment
  36. Analysis of pain-intensity measurements
  37. Topical review
  38. How to analyze the Visual Analogue Scale: Myths, truths and clinical relevance
  39. Editorial comment
  40. The relationship between chronic pain and cardiovascular disease: Squaring the circle?
  41. Systematic review
  42. Assessing the relationship between chronic pain and cardiovasculardisease: A systematic review and meta-analysis
  43. Editorial comment
  44. Optimists fare better when chronic pain strikes – Or does pain related disability make us pessimists?
  45. Observational study
  46. Constructs of health belief and disabling distal upper limb pain
  47. Editorial comment
  48. Attitude and belief of pain-therapists are important when trying to help chronic pain patients: The Norwegian version of the Pain Attitudes and Beliefs Scale (PABS) improved by Rasch analysis
  49. Observational study
  50. Rasch analysis resulted in an improved Norwegian version of the Pain Attitudes and Beliefs Scale(PABS)
  51. Editorial comment
  52. Anxiety could play a larger role than depression in migraine headache
  53. Clinical pain research
  54. The relative importance of anxiety and depression in pain impact in individuals with migraine headaches
  55. Editorial comment
  56. Bringing the lab to the people: Experimental pain testing in the general population
  57. Clinical pain research
  58. Pressure and cold pain threshold reference values in a large, young adult, pain-free population
  59. Editorial comment
  60. Improving pain treatment in children
  61. Clinical pain research
  62. A randomized controlled trial of amitriptyline versus gabapentin for complex regional pain syndrome type I and neuropathic pain in children
  63. Editorial comment
  64. Gut gateway to generalized pain
  65. Original experimental
  66. A low fermentable oligo-di-mono saccharides and polyols(FODMAP) diet reduced pain and improve ddaily life in fibromyalgia patients
  67. Editorial comment
  68. Measuring outcomes of pain management
  69. Clinical pain research
  70. Osteoarthritis patients with pain improvement are highly likely to also have improved quality of life and functioning. A post hoc analysis of a clinical trial
  71. Clinical pain research
  72. Construct validity and reliability of Finnish version of Örebro Musculoskeletal Pain Screening Questionnaire
  73. Observational study
  74. Total sleep deprivation and pain perception during cold noxious stimuli in humans
  75. Corrigendum
  76. Corrigendum to ‘Reliability of pressure pain threshold testing in healthy pain free young adults’ [Scand. J. Pain 9 (2015) 38–41]
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