The following is a summary of “Comparative effectiveness of different placebos and comparator groups for hand osteoarthritis exploring the impact of contextual factors: A systematic review and meta-analysis of randomized trials,” published in the July 2024 issue of Rheumatology by Balsby et al.

To investigate the efficacy of various comparators (placebos and untreated control groups) in alleviating pain among participants in hand osteoarthritis trials while examining the influence of contextual factors.

PubMed, EMBASE, and CENTRAL databases were systematically searched from inception to December 26, 2021. Randomized controlled trials involving individuals with hand osteoarthritis that utilized either a placebo or an untreated control group were included. The risk of bias was assessed using the Cochrane Risk-of-Bias tool version 2. Each comparator was contrasted against a null arm assumed to exhibit zero change from baseline, employing the same standard deviation as the comparator. Standardized mean differences were synthesized using random-effects meta-analysis. Meta-regression and stratified analyses explored the impact of contextual factors on pain outcomes.

Quantitative synthesis included 84 trials (7,262 participants), with 76 trials (6,462 participants) eligible for stratified analysis. Placebos demonstrated superior pain relief compared to null-arms, yielding an effect size of −0.51 (95% CI −0.61 to −0.42), whereas untreated control groups did not show significant pain reduction. Across all comparators, studies with blinded designs and a lower risk of bias exhibited greater pain relief than open-label trials and those with some concern or high risk of bias.

In hand osteoarthritis trials, rigorous blinding and lower risk of bias assessments enhanced placebo responses in pain management. Placebos outperformed null arms, whereas untreated control groups did not significantly alleviate pain. These findings underscore the critical importance of employing appropriate comparators in clinical trial designs to evaluate treatment efficacy accurately.

Source: sciencedirect.com/science/article/pii/S1063458424011622