Risk Factors of the Spread of COVID-19 in Prisoners: A Systematic Review and Meta-Analysis.

OBJECTIVES: This systematic review and meta-analysis aimed to identify and synthesize evidence on risk factors for COVID-19 in incarcerated populations. METHODS: A systematic search of PubMed, Scopus, and Google Scholar was conducted for English articles until October 2025. Study quality was assessed using the PRISMA checklist and NOS tool. Meta-analysis was performed in Stata 17 using a random-effects model, with odds ratios as the primary effect measure and statistical significance set at P < 0.05. Heterogeneity was evaluated via I2 statistics. RESULTS: Twelve articles were ultimately included in the study. For the meta-analysis, only 5 articles were considered, which evaluated sex, age, and vaccination status as the risk factors of COVID-19. The total sample size was 176169, consisting of 169117 males and 7,726 females. In most studies, the average age was reported to be around 40 years. Fully vaccinated prisoners were less likely to contract COVID-19 than unvaccinated ones (OR: 0.38; 95% CI: 0.22, 0.67; P = 0.001), while no significant relationships were found regarding sex and age. CONCLUSIONS: Our findings confirm that full vaccination significantly protects against COVID-19 in prisons. Prioritizing vaccination campaigns, along with measures like mask use and hand hygiene, is essential to protect incarcerated individuals and the wider community.