Steven J. Kamper

Global Rating of Change Scales: A Review of Strengths and Weaknesses and Considerations for Design

Abstract Most clinicians ask their patients to rate whether their health condition has improved or deteriorated over time and then use this information to guide management decisions. Many studies also use patient-rated change as an outcome measure to determine the efficacy of a particular treatment. Global rating of change (GRC) scales provide a method of obtaining this information in a manner that is quick, flexible, and efficient. As with any outcome measure, however, meaningful interpretation of results can only be undertaken with due consideration of the clinimetric properties, strengths, and weaknesses of the instrument. The purpose of this article is to summarize this information to assist appropriate interpretation of the GRC results and to provide evidence-informed advice to guide design and administration of GRC scales. These considerations are relevant and applicable to the use of GRC scales both in the clinic and in research.

Course and prognostic factors of whiplash: a systematic review and meta-analysis.

&NA; We conducted a systematic review and meta‐analysis of prospective cohort studies of subjects with acute whiplash injuries. The aim was to describe the course of recovery, pain and disability symptoms and also to assess the influence of different prognostic factors on outcome. Studies were selected for inclusion if they enrolled subjects with neck pain within six weeks of a car accident and measured pain and/or disability outcomes. Studies were located via a sensitive search of electronic databases; Medline, Embase, CINAHL, Cochrane database, ACP Journal club, DARE and Psychinfo and through hand‐searches of relevant previous reviews. Methodological quality of all studies was assessed using a six item checklist. Sixty‐seven articles, describing 38 separate cohorts were included. Recovery rates were extremely variable across studies but homogeneity was improved when only data from studies of more robust methodological quality were considered. These data suggest that recovery occurs for a substantial proportion of subjects in the initial 3 months after the accident but after this time recovery rates level off. Pain and disability symptoms also reduce rapidly in the initial months after the accident but show little improvement after 3 months have elapsed. Data regarding the prognostic factors associated with poor recovery were difficult to interpret due to heterogeneity of the techniques used to assess such associations and the way in which they are reported. There was also wide variation in the measurement of outcome and the use of validated measures would improve interpretability and comparability of future studies.

Global Perceived Effect scales provided reliable assessments of health transition in people with musculoskeletal disorders, but ratings are strongly influenced by current status

OBJECTIVE The study investigated the test-retest reliability and construct validity of the Global Perceived Effect (GPE) scale in patients with musculoskeletal disorders. STUDY DESIGN AND SETTING Data from seven clinical studies including 861 subjects were used for the analyses. Repeat measures taken at the same attendance and from attendances separated by 24 hours were compared to estimate test-retest reliability. Construct validity was evaluated by examining relationships between pre, post, and change scores in pain and disability measures with GPE measures. RESULTS Intraclass correlation coefficient values of 0.90-0.99 indicate excellent reproducibility of the GPE scale. In all but one data set, change scores on pain and disability measures correlated well (r=0.40-0.74) with GPE; however, post scores nearly always correlated even more strongly (r=0.58-0.84), and pre scores showed much weaker association (r=0.00-0.28). Pre scores accounted for only a small amount of additional R(2) when added to regression models including post score. CONCLUSIONS Test-retest reliability of the GPE is excellent. GPE ratings are strongly influenced by current status, with the effect more obvious as transition time lengthens. This result questions whether transition ratings truly reflect change, or rather just current state. This finding also has implications for the use of GPE ratings as an external criterion of change in clinimetric studies.

Multidisciplinary biopsychosocial rehabilitation for chronic low back pain: Cochrane systematic review and meta-analysis.

Objective To assess the long term effects of multidisciplinary biopsychosocial rehabilitation for patients with chronic low back pain. Design Systematic review and random effects meta-analysis of randomised controlled trials. Data sources Electronic searches of Cochrane Back Review Group Trials Register, CENTRAL, Medline, Embase, PsycINFO, and CINAHL databases up to February 2014, supplemented by hand searching of reference lists and forward citation tracking of included trials. Study selection criteria Trials published in full; participants with low back pain for more than three months; multidisciplinary rehabilitation involved a physical component and one or both of a psychological component or a social or work targeted component; multidisciplinary rehabilitation was delivered by healthcare professionals from at least two different professional backgrounds; multidisciplinary rehabilitation was compared with a non- multidisciplinary intervention. Results Forty one trials included a total of 6858 participants with a mean duration of pain of more than one year who often had failed previous treatment. Sixteen trials provided moderate quality evidence that multidisciplinary rehabilitation decreased pain (standardised mean difference 0.21, 95% confidence interval 0.04 to 0.37; equivalent to 0.5 points in a 10 point pain scale) and disability (0.23, 0.06 to 0.40; equivalent to 1.5 points in a 24 point Roland-Morris index) compared with usual care. Nineteen trials provided low quality evidence that multidisciplinary rehabilitation decreased pain (standardised mean difference 0.51, −0.01 to 1.04) and disability (0.68, 0.16 to 1.19) compared with physical treatments, but significant statistical heterogeneity across trials was present. Eight trials provided moderate quality evidence that multidisciplinary rehabilitation improves the odds of being at work one year after intervention (odds ratio 1.87, 95% confidence interval 1.39 to 2.53) compared with physical treatments. Seven trials provided moderate quality evidence that multidisciplinary rehabilitation does not improve the odds of being at work (odds ratio 1.04, 0.73 to 1.47) compared with usual care. Two trials that compared multidisciplinary rehabilitation with surgery found little difference in outcomes and an increased risk of adverse events with surgery. Conclusions Multidisciplinary biopsychosocial rehabilitation interventions were more effective than usual care (moderate quality evidence) and physical treatments (low quality evidence) in decreasing pain and disability in people with chronic low back pain. For work outcomes, multidisciplinary rehabilitation seems to be more effective than physical treatment but not more effective than usual care.

Analgesic effects of treatments for non-specific low back pain: a meta-analysis of placebo-controlled randomized trials

OBJECTIVE Estimates of treatment effects reported in placebo-controlled randomized trials are less subject to bias than those estimates provided by other study designs. The objective of this meta-analysis was to estimate the analgesic effects of treatments for non-specific low back pain reported in placebo-controlled randomized trials. METHODS Medline, Embase, Cinahl, PsychInfo and Cochrane Central Register of Controlled Trials databases were searched for eligible trials from earliest records to November 2006. Continuous pain outcomes were converted to a common 0-100 scale and pooled using a random effects model. RESULTS A total of 76 trials reporting on 34 treatments were included. Fifty percent of the investigated treatments had statistically significant effects, but for most the effects were small or moderate: 47% had point estimates of effects of <10 points on the 100-point scale, 38% had point estimates from 10 to 20 points and 15% had point estimates of >20 points. Treatments reported to have large effects (>20 points) had been investigated only in a single trial. CONCLUSIONS This meta-analysis revealed that the analgesic effects of many treatments for non-specific low back pain are small and that they do not differ in populations with acute or chronic symptoms.

Treatment-based subgroups of low back pain: A guide to appraisal of research studies and a summary of current evidence

There has been a recent increase in research evaluating treatment-based subgroups of non-specific low back pain. The aim of these sub-classification schemes is to identify subgroups of patients who will respond preferentially to one treatment as opposed to another. Our article provides accessible guidance on to how to interpret this research and determine its implications for clinical practice. We propose that studies evaluating treatment-based subgroups can be interpreted in the context of a three-stage process: (1) hypothesis generation-proposal of clinical features to define subgroups; (2) hypothesis testing-a randomised controlled trial (RCT) to test that subgroup membership modifies the effect of a treatment; and (3) replication-another RCT to confirm the results of stage 2 and ensure that findings hold beyond the specific original conditions. At this point, the bulk of research evidence in defining subgroups of patients with low back pain is in the hypothesis generation stage; no classification system is supported by sufficient evidence to recommend implementation into clinical practice.

How does pain lead to disability? A systematic review and meta-analysis of mediation studies in people with back and neck pain

Abstract Disability is an important outcome from a clinical and public health perspective. However, it is unclear how disability develops in people with low back pain or neck pain. More specifically, the mechanisms by which pain leads to disability are not well understood. Mediation analysis is a way of investigating these mechanisms by examining the extent to which an intermediate variable explains the effect of an exposure on an outcome. This systematic review and meta-analysis aimed to identify and examine the extent to which putative mediators explain the effect of pain on disability in people with low back pain or neck pain. Five electronic databases were searched. We found 12 studies (N = 2961) that examined how pain leads to disability with mediation analysis. Standardized regression coefficients (&bgr;) of the indirect and total paths were pooled. We found evidence to show that self-efficacy (&bgr; = 0.23, 95% confidence interval [CI] = 0.10 to 0.34), psychological distress (&bgr; = 0.10, 95% CI = 0.01 to 0.18), and fear (&bgr; = 0.08, 95% CI = 0.01 to 0.14) mediated the relationship between pain and disability, but catastrophizing did not (&bgr; = 0.07, 95% CI = −0.06 to 0.19). The methodological quality of these studies was low, and we highlight potential areas for development. Nonetheless, the results suggest that there are significant mediating effects of self-efficacy, psychological distress, and fear, which underpins the direct targeting of these constructs in treatment.

Symptoms of depression and stress mediate the effect of pain on disability

&NA; The mechanism or mechanisms involved in the development of pain‐related disability in people with low back pain is unclear. Psychological distress has been identified as one potential pathway by which an episode of pain influences the development of persistent disabling symptoms; however, the relationship has not been formally investigated. This study investigated the causal relationship between pain and disability via psychological distress (and its components depression, stress, and anxiety) by using mediation path analysis. The study sample included 231 participants with subacute low back pain (6 to 12 weeks’ pain duration) who had been recruited for an exercise‐based randomised, controlled trial. All participants completed self‐report assessments of pain (0–10 numerical rating scale), disability (Roland Morris Disability Questionnaire), and psychological distress (Depression Anxiety and Stress Scale) at baseline and again at 2 follow‐up time points (6 and 12 weeks after baseline). The results of the mediation analysis suggest that approximately 30% of the relationship between subacute pain and later disability is dependent on the level of patients’ psychological distress. The finding that psychological distress only partially (30%) mediated the pain‐disability relationship indicates that other factors should also be explored. Further analysis into the components of psychological distress revealed that the symptoms of depression and stress, but not anxiety, are responsible for mediation of the pain‐disability relationship. These findings provide an opportunity to decrease the risk of long‐term disability through early identification and management of depressive and stress symptoms. Psychological distress symptoms at 6 weeks in patients with low back pain influences future disability. Symptoms of depression and stress, but not anxiety, are responsible for mediation of the pain‐disability relationship

Can We Explain Heterogeneity Among Randomized Clinical Trials of Exercise for Chronic Back Pain? A Meta-Regression Analysis of Randomized Controlled Trials

Background Exercise programs may vary in terms of duration, frequency, and dosage; whether they are supervised; and whether they include a home-based program. Uncritical pooling of heterogeneous exercise trials may result in misleading conclusions regarding the effects of exercise on chronic low back pain (CLBP). Purpose The purpose of this study was to establish the effect of exercise on pain and disability in patients with CLBP, with a major aim of explaining between-trial heterogeneity. Data Sources Six databases were searched up to August 2008 using a computerized search strategy. Study Selection Eligible studies needed to be randomized clinical trials evaluating the effects of exercise for nonspecific CLBP. Outcomes of interest were pain and disability measured on a continuous scale. Data Extraction Baseline demographic data, exercise features, and outcome data were extracted from all included trials. Data Synthesis Univariate meta-regressions were conducted to assess the associations between exercise effect sizes and 8 study-level variables: baseline severity of symptoms, number of exercise hours and sessions, supervision, individual tailoring, cognitive-behavioral component, intention-to-treat analysis, and concealment of allocation. Limitations Only study-level characteristics were included in the meta-regression analyses. Therefore, the implications of the findings should not be used to differentiate the likelihood of the effect of exercise based on patient characteristics. Conclusions The results show that, in general, when all types of exercise are analyzed, small but significant reductions in pain and disability are observed compared with minimal care or no treatment. Despite many possible sources of heterogeneity in exercise trials, only dosage was found to be significantly associated with effect sizes.

The Epidemiology and Economic Consequences of Pain

Pain is considered a major clinical, social, and economic problem in communities around the world. In this review, we describe the incidence, prevalence, and economic burden of pain conditions in children, adolescents, and adults based on an electronic search of the MEDLINE and EMBASE databases for articles published from January 1, 2000, through August 1, 2014, using the keywords pain, epidemiology, burden, prevalence, and incidence. The impact of pain on individuals and potential risk factors are also discussed. Differences in the methodology and conduct of epidemiological studies make it difficult to provide precise estimates of prevalence and incidence; however, the burden of pain is unquestionably large. Improved concepts and methods are needed in order to study pain from a population perspective and further the development of pain prevention and management strategies.