Applying thematic synthesis to interpretation and commentary in epidemiological studies: identifying what contributes to successful interventions to promote hand hygiene in patient care.

The analytical themes help to explain the original authors' perceptions of the degree to which interventions were effective and suggested new directions for research: exploring ways to avoid the Hawthorne effect; exploring the impact of components of multimodal interventions; the use of theoretical frameworks for behaviour change; potential to embed interventions into wider patient safety initiatives; adaptations to demonstrate sustainability; and the development of systematic approaches to implementation. Our findings corroborate studies exploring the success or failure of other clinical interventions: context and leadership are important.