Does colchicine reduce mortality in patients with COVID-19 clinical syndrome? An umbrella review of published meta-analyses

Background: Despite significant improvements in both treatment and prevention strategies, as well as multiple commissioned reviews, there remains uncertainty regarding the survival benefit of repurposed drugs such as colchicine in patients with Coronavirus Disease 2019 (COVID-19) clinical syndrome. Methods: In this umbrella review, we carried out a comprehensive search of PubMed, EMBASE, Cochrane Database of Systematic Reviews, Science Citation Index, and the Database of Abstracts of Reviews of Effectiveness between January 1, 2020 and January 31, 2023 for systematic reviews and meta-analyses evaluating the mortality-reducing benefits of colchicine in patients with COVID-19. This was to ascertain the exact relationship between colchicine exposure and mortality outcomes in these cohorts of patients. We utilized A Measurement Tool to Assess systematic Reviews-2 (AMSTAR-2) to conduct an exhaustive methodological quality and risk of bias assessment of the included reviews. Results: We included eighteen meta-analyses (n = 199,932 participants) in this umbrella review. Colchicine exposure was associated with an overall reduction of about 32% in the risk of mortality (odds ratio 0.68, confidence interval [CI] 0.58–0.78; I2 = 94%, p = 0.001). Further examination of pooled estimates of mortality outcomes by the quality effects model (corrected for the methodological quality and risk of bias of the constituent reviews) reported similar point estimates (OR 0.73; CI 0.59 to 0.91; I2 = 94%). Conclusion: In a pooled umbrella evaluation of published meta-analyses of COVID-19 patient cohorts, exposure to colchicine was associated with a reduction in overall mortality. Although it remains uncertain if this effect could potentially be attenuated or augmented by COVID-19 vaccination.