Physical interventions to interrupt or reduce the spread of respiratory viruses. Part 2 - Hand hygiene and other hygiene measures: systematic review and meta-analysis.

Lubna A Al-Ansary; Ghada A Bawazeer; Elaine Beller; Justin Clark; John Conly; Chris Del Mar; Elizabeth Dooley; Eliana Ferroni; Paul Glasziou; Tammy Hoffman; Tom Jefferson; Sarah Thorning; Mieke van Driel; Mark Jones

Though the studies reviewed make it clear that hand hygiene has a modest effect, several questions remain unanswered. First, the high heterogeneity means there may be substantial differences in the effect of different interventions. The poor reporting limited our ability to extract the information needed to assess any "dose response" relationship. Second, the sustainability of hand washing is unclear: some programmes achieved 5 to 10 hand washings per day, but compliance may diminish with time, as motivation decreases or because of adverse effects from frequent hand washing. Third, there is still little information on combinations of hand washing with other interventions, and how those are best introduced and sustained. Finally, and perhaps most importantly, most interventions were intensive within small organisations, and the ability to scale these up to national-level interventions is unclear.