OBJECTIVES: To analyse the impact of placebo effects on outcome in trials of selected minimally invasive procedures and to assess reported adverse events in both trial arms.
DESIGN: A systematic review and meta-analysis.
DATA SOURCES AND STUDY SELECTION: We searched MEDLINE and Cochrane library to identify systematic reviews of musculoskeletal, neurological and cardiac conditions published between January 2009 and January 2014 comparing selected minimally invasive with placebo (sham) procedures. We searched MEDLINE for additional randomised controlled trials published between January 2000 and January 2014.
DATA SYNTHESIS: Effect sizes (ES) in the active and placebo arms in the trials' primary and pooled secondary end points were calculated. Linear regression was used to analyse the association between end points in the active and sham groups. Reported adverse events in both trial arms were registered.
RESULTS: We included 21 trials involving 2519 adult participants. For primary end points, there was a large clinical effect (ES≥0.8) after active treatment in 12 trials and after sham procedures in 11 trials. For secondary end points, 7 and 5 trials showed a large clinical effect. Three trials showed a moderate difference in ES between active treatment and sham on primary end points (ES ≥0.5) but no trials reported a large difference. No trials showed large or moderate differences in ES on pooled secondary end points. Regression analysis of end points in active treatment and sham arms estimated an R(2) of 0.78 for primary and 0.84 for secondary end points. Adverse events after sham were in most cases minor and of short duration.
CONCLUSIONS: The generally small differences in ES between active treatment and sham suggest that non-specific mechanisms, including placebo, are major predictors of the observed effects. Adverse events related to sham procedures were mainly minor and short-lived. Ethical arguments frequently raised against sham-controlled trials were generally not substantiated.
BACKGROUND: Radiofrequency (RF) denervation, an invasive treatment for chronic low back pain (CLBP), is used most often for pain suspected to arise from facet joints, sacroiliac (SI) joints or discs. Many (uncontrolled) studies have shown substantial variation in its use between countries and continued uncertainty regarding its effectiveness.
OBJECTIVES: The objective of this review is to assess the effectiveness of RF denervation procedures for the treatment of patients with CLBP. The current review is an update of the review conducted in 2003.
SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, three other databases, two clinical trials registries and the reference lists of included studies from inception to May 2014 for randomised controlled trials (RCTs) fulfilling the inclusion criteria. We updated this search in June 2015, but we have not yet incorporated these results.
SELECTION CRITERIA: We included RCTs of RF denervation for patients with CLBP who had a positive response to a diagnostic block or discography. We applied no language or date restrictions.
DATA COLLECTION AND ANALYSIS: Pairs of review authors independently selected RCTs, extracted data and assessed risk of bias (RoB) and clinical relevance using standardised forms. We performed meta-analyses with clinically homogeneous studies and assessed the quality of evidence for each outcome using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach.
MAIN RESULTS: In total, we included 23 RCTs (N = 1309), 13 of which (56%) had low RoB. We included both men and women with a mean age of 50.6 years. We assessed the overall quality of the evidence as very low to moderate. Twelve studies examined suspected facet joint pain, five studies disc pain, two studies SI joint pain, two studies radicular CLBP, one study suspected radiating low back pain and one study CLBP with or without suspected radiation. Overall, moderate evidence suggests that facet joint RF denervation has a greater effect on pain compared with placebo over the short term (mean difference (MD) -1.47, 95% confidence interval (CI) -2.28 to -0.67). Low-quality evidence indicates that facet joint RF denervation is more effective than placebo for function over the short term (MD -5.53, 95% CI -8.66 to -2.40) and over the long term (MD -3.70, 95% CI -6.94 to -0.47). Evidence of very low to low quality shows that facet joint RF denervation is more effective for pain than steroid injections over the short (MD -2.23, 95% CI -2.38 to -2.08), intermediate (MD -2.13, 95% CI -3.45 to -0.81), and long term (MD -2.65, 95% CI -3.43 to -1.88). RF denervation used for disc pain produces conflicting results, with no effects for RF denervation compared with placebo over the short and intermediate term, and small effects for RF denervation over the long term for pain relief (MD -1.63, 95% CI -2.58 to -0.68) and improved function (MD -6.75, 95% CI -13.42 to -0.09). Lack of evidence of short-term effectiveness undermines the clinical plausibility of intermediate-term or long-term effectiveness. When RF denervation is used for SI joint pain, low-quality evidence reveals no differences from placebo in effects on pain (MD -2.12, 95% CI -5.45 to 1.21) and function (MD -14.06, 95% CI -30.42 to 2.30) over the short term, and one study shows a small effect on both pain and function over the intermediate term. RF denervation is an invasive procedure that can cause a variety of complications. The quality and size of original studies were inadequate to permit assessment of how often complications occur.
AUTHORS' CONCLUSIONS: The review authors found no high-quality evidence suggesting that RF denervation provides pain relief for patients with CLBP. Similarly, we identified no convincing evidence to show that this treatment improves function. Overall, the current evidence for RF denervation for CLBP is very low to moderate in quality; high-quality evidence is lacking. High-quality RCTs with larger patient samples are needed, as are data on long-term effects.
BACKGROUND: Radiofrequency ablation (RFA), a procedure using heat to interrupt pain signals in spinal nerves, is an emerging treatment option for chronic low back pain. Its clinical efficacy has not yet been established.
OBJECTIVE: To determine the efficacy of RFA for chronic low back pain associated with lumbar facet joints, sacroiliac joints, discogenic low back pain and the coccyx.
METHODS: A systematic review was conducted. Medline, EMBASE, PubMed, SPORTDiscus, CINAHL and the Cochrane Library were searched up to August 2013. Abstracts and full-text articles were reviewed in duplicate. Included articles were sham-controlled randomized controlled trials (RCTs), assessed the efficacy of RFA, reported at least one month of follow-up and included participants who had experienced back pain for at least three months. Data were extracted in duplicate and quality was assessed using the Cochrane Risk of Bias tool. Due to heterogeneity, as well as a lack of reported mean differences and SDs, meta-analysis was not possible using these data.
RESULTS: The present systematic review retrieved 1063 abstracts. Eleven sham-controlled RCTs were included: three studies involving discogenic back pain; six studies involving lumbar facet joint pain; and two studies involving sacroiliac joint pain. No studies were identified assessing the coccyx. The evidence supports RFA as an efficacious treatment for lumbar facet joint and sacroiliac joint pain, with five of six and both of the RCTs demonstrating statistically significant pain reductions, respectively. The evidence supporting RFA for the treatment of discogenic pain is mixed.
CONCLUSIONS: While the majority of the studies focusing on lumbar facet joints and sacroiliac joints suggest that RFA significantly reduces pain in short-term follow-up, the evidence base for discogenic low back pain is mixed. There is no RCT evidence for RFA for the coccyx. Future studies should examine the clinical significance of the achieved pain reduction and the long-term efficacy of RFA.
Journal»European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society
To analyse the impact of placebo effects on outcome in trials of selected minimally invasive procedures and to assess reported adverse events in both trial arms.
DESIGN:
A systematic review and meta-analysis.
DATA SOURCES AND STUDY SELECTION:
We searched MEDLINE and Cochrane library to identify systematic reviews of musculoskeletal, neurological and cardiac conditions published between January 2009 and January 2014 comparing selected minimally invasive with placebo (sham) procedures. We searched MEDLINE for additional randomised controlled trials published between January 2000 and January 2014.
DATA SYNTHESIS:
Effect sizes (ES) in the active and placebo arms in the trials' primary and pooled secondary end points were calculated. Linear regression was used to analyse the association between end points in the active and sham groups. Reported adverse events in both trial arms were registered.
RESULTS:
We included 21 trials involving 2519 adult participants. For primary end points, there was a large clinical effect (ES≥0.8) after active treatment in 12 trials and after sham procedures in 11 trials. For secondary end points, 7 and 5 trials showed a large clinical effect. Three trials showed a moderate difference in ES between active treatment and sham on primary end points (ES ≥0.5) but no trials reported a large difference. No trials showed large or moderate differences in ES on pooled secondary end points. Regression analysis of end points in active treatment and sham arms estimated an R(2) of 0.78 for primary and 0.84 for secondary end points. Adverse events after sham were in most cases minor and of short duration.
CONCLUSIONS:
The generally small differences in ES between active treatment and sham suggest that non-specific mechanisms, including placebo, are major predictors of the observed effects. Adverse events related to sham procedures were mainly minor and short-lived. Ethical arguments frequently raised against sham-controlled trials were generally not substantiated.
