The association between alcohol consumption and osteoarthritis: a meta-analysis and meta-regression of observational studies

To K, Mak C, Zhang C, Zhou Y, Filbay S, Khan W · Rheumatology International

A worked example of an association dissolving under adjustment. Pooled across all studies, any alcohol consumption was associated with less osteoarthritis (OR 0.79, 95% CI 0.68-0.93), and weekly-or-more with the same (0.79, 0.65-0.97), holding for radiographic (0.83), hand (0.80) and knee OA (0.85). But in unadjusted data the OR was 0.70 (0.55-0.89), and in studies adjusted for any covariate it was 0.93 (0.78-1.10) — no association. The authors' own conclusion is that the analysis dispels the notion that alcohol protects against osteoarthritis.

Population

29 observational studies including 25,192 people with osteoarthritis

Intervention

Any alcohol consumption, and weekly or more frequent consumption

Comparator

Non-drinkers

Limitations

Observational studies only, mostly cross-sectional, with the exposure self-reported and the reference group of non-drinkers contaminated by people who stopped drinking because they were unwell. Risk of bias assessed on the Newcastle-Ottawa Scale; publication bias examined by funnel and Galbraith plots.