Background: Outcomes research involves the secondary analysis of data collected routinely by clinical services, in order to judge the effectiveness of interventions and policy initiatives. It permits the study of large databases of patients who are representative of 'real world' practice. However, there are potential problems with this observational design.
Aims: To establish the strengths and limitations of outcomes research when applied in mental health.
Method: A systematic review was made of the application of outcomes research in mental health services research.
Results: Nine examples of outcomes research in mental health services were found. Those that used insurance claims data have information on large numbers of patients but use surrogate outcomes that are of questionable value to clinicians and patients. Problems arise when attempting to adjust for important confounding variables using routinely collected claims data, making results difficult to interpret.
Conclusions: Outcomes research is unlikely to be a quick or cheap means of establishing evidence for the effectiveness of mental health practice and policy.