Handwashing and risk of respiratory infections: a quantitative systematic review.

An evaluation of 8 eligible studies (from a primary list of 410 articles) showed that handwashing lowered risks of respiratory infection, with risk reductions ranging from 6% to 44% [pooled value 24% (95% CI 6–40%)]. Pooling the results of only the seven homogenous studies gave a relative risk of 1.19 (95% CI 1.12%–1.26%), implying that hand cleansing can cut the risk of respiratory infection by 16% (95% CI 11–21%). However, studies were of poor quality, none related to developing countries, and only one to severe disease. Tropical Medicine and International Health, 2006; 11 258-267.