OBJECTIVES: To investigate how best to encourage health professionals to promote, and for people with asthma to use, asthma action plans. METHODS: Systematic review. Randomised controlled trials published between 1960 and 2006 were searched using multiple electronic databases. Unpublished and ongoing studies were identified by contacting asthma experts internationally. Included trials reported outcome data for the promotion of action plans including issue of plans by health professionals, and patient ownership and use. RESULTS: 14 trials satisfied our study inclusion criteria. Of these, only four studies reported data for action plan use. Interventions included: education of doctors and people with asthma; telephone reinforcement; partially...