Hand washing: a ritual revisited.

This article summarizes a critical analysis of 18 studies that examined the link between hand washing and infection. Although several factors made it difficult to evaluate the effect of hand washing, the authors conclude that (1) hand washing can add incremental value to infection-control strategies in acute care settings, (2) patient hand hygiene may influence infection rates, and (3) the effect of "ideal" hand washing on nosocomial infection rates is unlikely to be quantifiable.