Luciana A. C. Machado

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.

Cost-effectiveness of guideline-endorsed treatments for low back pain: a systematic review

Healthcare costs for low back pain (LBP) are increasing rapidly. Hence, it is important to provide treatments that are effective and cost-effective. The purpose of this systematic review was to investigate the cost-effectiveness of guideline-endorsed treatments for LBP. We searched nine clinical and economic electronic databases and the reference list of relevant systematic reviews and included studies for eligible studies. Economic evaluations conducted alongside randomised controlled trials investigating treatments for LBP endorsed by the guideline of the American College of Physicians and the American Pain Society were included. Two independent reviewers screened search results and extracted data. Data extracted included the type and perspective of the economic evaluation, the treatment comparators, and the relative cost-effectiveness of the treatment comparators. Twenty-six studies were included. Most studies found that interdisciplinary rehabilitation, exercise, acupuncture, spinal manipulation or cognitive-behavioural therapy were cost-effective in people with sub-acute or chronic LBP. Massage alone was unlikely to be cost-effective. There were inconsistent results on the cost-effectiveness of advice, insufficient evidence on spinal manipulation for people with acute LBP, and no evidence on the cost-effectiveness of medications, yoga or relaxation. This review found evidence supporting the cost-effectiveness of the guideline-endorsed treatments of interdisciplinary rehabilitation, exercise, acupuncture, spinal manipulation and cognitive-behavioural therapy for sub-acute or chronic LBP. There is little or inconsistent evidence for other treatments endorsed in the guideline.

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 effectiveness of the McKenzie method in addition to first-line care for acute low back pain: a randomized controlled trial

BackgroundLow back pain is a highly prevalent and disabling condition worldwide. Clinical guidelines for the management of patients with acute low back pain recommend first-line treatment consisting of advice, reassurance and simple analgesics. Exercise is also commonly prescribed to these patients. The primary aim of this study was to evaluate the short-term effect of adding the McKenzie method to the first-line care of patients with acute low back pain.MethodsA multi-centre randomized controlled trial with a 3-month follow-up was conducted between September 2005 and June 2008. Patients seeking care for acute non-specific low back pain from primary care medical practices were screened. Eligible participants were assigned to receive a treatment programme based on the McKenzie method and first-line care (advice, reassurance and time-contingent acetaminophen) or first-line care alone, for 3 weeks. Primary outcome measures included pain (0-10 Numeric Rating Scale) over the first seven days, pain at 1 week, pain at 3 weeks and global perceived effect (-5 to 5 scale) at 3 weeks. Treatment effects were estimated using linear mixed models.ResultsOne hundred and forty-eight participants were randomized into study groups, of whom 138 (93%) completed the last follow-up. The addition of the McKenzie method to first-line care produced statistically significant but small reductions in pain when compared to first-line care alone: mean of -0.4 points (95% confidence interval, -0.8 to -0.1) at 1 week, -0.7 points (95% confidence interval, -1.2 to -0.1) at 3 weeks, and -0.3 points (95% confidence interval, -0.5 to -0.0) over the first 7 days. Patients receiving the McKenzie method did not show additional effects on global perceived effect, disability, function or on the risk of persistent symptoms. These patients sought less additional health care than those receiving only first-line care (P = 0.002).ConclusionsWhen added to the currently recommended first-line care of acute low back pain, a treatment programme based on the McKenzie method does not produce appreciable additional short-term improvements in pain, disability, function or global perceived effect. However, the McKenzie method seems to reduce health utilization although it does not reduce patients risk of developing persistent symptoms.Trial RegistrationAustralian New Zealand Clinical Trials Registry: ACTRN12605000032651

Cost-effectiveness of general practice care for low back pain: a systematic review

Care from a general practitioner (GP) is one of the most frequently utilised healthcare services for people with low back pain and only a small proportion of those with low back pain who seek care from a GP are referred to other services. The aim of this systematic review was to evaluate the evidence on cost-effectiveness of GP care in non-specific low back pain. We searched clinical and economic electronic databases, and the reference list of relevant systematic reviews and included studies to June 2010. Economic evaluations conducted alongside randomised controlled trials with at least one GP care arm were eligible for inclusion. Two reviewers independently screened search results and extracted data. Eleven studies were included; the majority of which conducted a cost-effectiveness or cost-utility analysis. Most studies investigated the cost-effectiveness of usual GP care. Adding advice, education and exercise, or exercise and behavioural counselling, to usual GP care was more cost-effective than usual GP care alone. Clinical rehabilitation and/or occupational intervention, and acupuncture were more cost-effective than usual GP care. One study investigated the cost-effectiveness of guideline-based GP care, and found that adding exercise and/or spinal manipulation was more cost-effective than guideline-based GP care alone. In conclusion, GP care alone did not appear to be the most cost-effective treatment option for low back pain. GPs can improve the cost-effectiveness of their treatment by referring their patients for additional services, such as advice and exercise, or by providing the services themselves.

Imperfect placebos are common in low back pain trials: a systematic review of the literature.

The placebo is an important tool to blind patients to treatment allocation and therefore minimise some sources of bias in clinical trials. However, placebos that are improperly designed or implemented may introduce bias into trials. The purpose of this systematic review was to evaluate the adequacy of placebo interventions used in low back pain trials. Electronic databases were searched systematically for randomised placebo-controlled trials of conservative interventions for low back pain. Trial selection and data extraction were performed by two reviewers independently. A total of 126 trials using over 25 different placebo interventions were included. The strategy most commonly used to enhance blinding was the provision of structurally equivalent placebos. Adequacy of blinding was assessed in only 13% of trials. In 20% of trials the placebo intervention was a potentially genuine treatment. Most trials that assessed patients’ expectations showed that the placebo generated lower expectations than the experimental intervention. Taken together, these results demonstrate that imperfect placebos are common in low back pain trials; a result suggesting that many trials provide potentially biased estimates of treatment efficacy. This finding has implications for the interpretation of published trials and the design of future trials. Implementation of strategies to facilitate blinding and balance expectations in randomised groups need a higher priority in low back pain research.

Prevalence of chronic musculoskeletal disorders in elderly Brazilians: a systematic review of the literature

BackgroundPopulation ageing is a worldwide phenomenon that has recently challenged public healthcare systems. The knowledge of the burden of chronic musculoskeletal disorders in elders is still limited, particularly in the developing world. This systematic review aimed to investigate the prevalence of chronic musculoskeletal disorders in elderly Brazilians.MethodsA comprehensive literature search was performed in five electronic databases (from inception to January 2012) and completed by additional searches in reference lists. Two review authors independently selected the eligible studies and extracted data on participants’ characteristics and rates of chronic musculoskeletal disorders. One review author extracted methodological quality data. We performed a critical synthesis of the results, which were grouped into the diagnoses “chronic musculoskeletal pain” or “specific musculoskeletal diagnoses”.ResultsTwenty five studies reporting on a total of 116,091 elderly Brazilians were included. Eight studies (32%) were of high methodological quality. There was a large variation in the measure of prevalence used by individual studies and in their definition of chronic pain. Prevalence estimates reached 86% for chronic musculoskeletal pain in any location. Studies investigating multiple pain sites found the lower limb and the spine to be the most prevalent complaints (50% each). Arthritis and rheumatism (including osteoarthritis) were the most prevalent specific musculoskeletal diagnoses (9% to 40%), followed by herniated disc (6% to 27%).ConclusionsDespite the growth of the elderly population worldwide, high-quality research on the burden of chronic musculoskeletal disorders in the elderly is still scarce. Future healthcare research focusing on this age group should be a priority in developing countries since their public healthcare systems are not yet fully prepared to accommodate the needs of an aging population.

Responsiveness of the 24-, 18- and 11-item versions of the Roland Morris Disability Questionnaire.

Several versions of the 24-item Roland Morris Disability Questionnaire (RMDQ) have been proposed; however, their responsiveness has not been extensively explored. The objective of this study was to compare the responsiveness of four versions of the RMDQ. Perceived disability was measured using the 24-item, two 18-item and an 11-item RMDQ on 1,069 low back pain patients from six randomised controlled trials. Responsiveness was calculated using effect size, Guyatt’s responsiveness index (GRI) and receiver operating characteristics (ROC) curves. Effect size analyses showed that both 18-item versions of the RMDQ were superior to the 24- and 11-item versions of the RMDQ. GRI showed that the 24- and 18-item versions of the RMDQ were similar but more responsive than the 11-item. ROC curves revealed that the 11-item was less responsive than the other three versions, which had similar responsiveness. The results of this study demonstrate that the 24-item and both 18-item versions of the RMDQ have similar responsiveness with all having superior responsiveness to the 11-item.

Trial methodology and patient characteristics did not influence the size of placebo effects on pain

OBJECTIVE To determine whether trial-design, patient-type, or placebo-type factors influence the size of the placebo analgesic effect in clinical trials. STUDY DESIGN AND SETTING Trials that measured pain outcomes in Hróbjartsson and Gøtzsches meta-analysis were retrieved and coded for eight factors potentially predictive of placebo effect size. Random effects meta-regression was used to explore the predictive power of each factor on placebo effect size. The factors investigated aspects of trial design (nonstandardized co-analgesia, co-intervention), patients (pain type, patient group, residual pain score), and placebo (placebo type, indistinguishability, structural equivalence). The meta-analysis undertaken in the original study was also repeated to confirm the results. RESULTS The pooled effect of placebo was 3.2 points on a 100-point scale (95% confidence interval [CI]=1.6-4.7). None of the selected factors influenced the size of placebo effect: the effect of all factors was close to zero, all CIs spanned 0, and P-values ranged from 0.13 to 0.90. CONCLUSION This study confirms the findings of previous researchers that, at present, the evidence for large placebo analgesic effects in clinical trials is lacking. Importantly, this analysis also establishes that larger placebo effects are not associated with particular aspects of the trial methodology, patient, or placebo type.

The McKenzie Method for the management of acute non-specific low back pain: design of a randomised controlled trial [ACTRN012605000032651].

BackgroundLow back pain (LBP) is a major health problem. Effective treatment of acute LBP is important because it prevents patients from developing chronic LBP, the stage of LBP that requires costly and more complex treatment.Physiotherapists commonly use a system of diagnosis and exercise prescription called the McKenzie Method to manage patients with LBP. However, there is insufficient evidence to support the use of the McKenzie Method for these patients. We have designed a randomised controlled trial to evaluate whether the addition of the McKenzie Method to general practitioner care results in better outcomes than general practitioner care alone for patients with acute LBP.Methods/designThis paper describes the protocol for a trial examining the effects of the McKenzie Method in the treatment of acute non-specific LBP. One hundred and forty eight participants who present to general medical practitioners with a new episode of acute non-specific LBP will be randomised to receive general practitioner care or general practitioner care plus a program of care based on the McKenzie Method. The primary outcomes are average pain during week 1, pain at week 1 and 3 and global perceived effect at week 3.DiscussionThis trial will provide the first rigorous test of the effectiveness of the McKenzie Method for acute non-specific LBP.