A perspective on studies of anaesthesia morbidity and mortality.

Adverse outcomes arising from the delivery of healthcare have been the focus of extensive study in recent years. Overall, the incidence of anaesthesia complications has declined over several decades. However, the ability to interpret outcome data can be extremely difficult, as studies differ considerably with respect to the country of origin, the population examined, and the methodology employed. This review examines the importance of study design and country of origin in interpreting morbidity and mortality studies, and provides some guidelines for future studies to help overcome the problems of mortality and morbidity data comparison.