Measuring handwashing performance in health service audits and research studies.

Handwashing is regarded as the most effective way of controlling healthcare-associated infection. A search of the literature identified 42 intervention studies seeking to increase compliance in which the data were collected by directly observing practice. The methods used to undertake observation were so poorly described in most studies that it is difficult to accept the findings as reliable or as valid indicators of health worker behaviour. Most studies were limited in scope, assessing the frequency of handwashing in critical care units. The ethical implications of watching health workers during close patient contact were not considered, especially when observation was covert or health workers were misinformed about the purpose of the study. Future studies should take place in a range of clinical settings to increase the generalizability of findings. Observation should be timed to capture a complete picture of 24h activity and should include all health workers in contact with patients because all have the potential to contribute to cross-infection. Reported details of observation should include: vantage of data collectors; inter-rater reliability when more than one individual is involved; and attempts to overcome the impact of observation on usual health worker behaviour. Ideally an additional data collection method should be used to corroborate or refute the findings of observation, but no well-validated method is presently available.