Given the more integrated and comprehensive data infrastructure in hospitals, safety in that setting is potentially seen as more inviting for researchers. Despite these difficulties, a number of highly innovative studies have examined safety in primaiy and ambulatory care. But the lack of consistent data and a range of methods used to measure harm have delivered very wide-ranging results. Systematic reviews suggest that safety lapses occur between 1 and 24 times in every 100 primary/ambulatory care consultations. The hann most commonly stems from diagnostic errors (and subsequent delays in treatment or therapy) and adverse drug events (ADEs).