A flow diagram to facilitate selection of interventions and research for health care.

Decisions about health care should be informed by systematic review of valid research evidence on the effects of interventions on health outcomes that matter. If systematic review suggests it is likely that a health care intervention does more good than harm in some settings, questions must be addressed about the local applicability of the intervention, its cost-effectiveness, and feasibility of implementation. If systematic review suggests that it is unlikely that an intervention does more good than harm in any setting, its use should be discouraged, while existing interventions are improved or alternative interventions developed. If it is uncertain whether an intervention does more good than harm, further analysis of existing data or new controlled trials are required. The article contains a flow diagram, which provides a structure for making such decisions.