OBJECTIVES: There is growing interest in using patient-reported outcome (PRO) measures, which can complement clinical measures, to improve the quality of health care.  The amount of PRO data being captured by health care databases, however, is unknown.  To help identify data sources that capture PRO measures and the types of PRO data they collect, a systematic review was conducted in B.R.I.D.G.E. TO DATA® (www.bridgetodata.org), an online resource of population healthcare database profiles worldwide.  METHODS: PRO data were categorized into 9 dimensions of health status (Fitzpatrick et al., 1998): physical function, symptoms, self-judgments of health, psychological well-being, social well-being, cognitive function, role activities, personal constructs, and satisfaction with care.  To identify data sources collecting PRO data, 154 database profiles in www.bridgetodata.org were individually reviewed.  The PRO category and specific data subcategory (e.g., symptoms-appetite) were also extracted.  RESULTS: A review of 154 database profiles resulted in the identification of 34 databases that collect data on: physical function (22), symptoms (19), psychological well-being (15), social well-being (11), cognitive function (9), role activities (6), personal constructs (4), satisfaction with care (2), and self-judgments of health (1).  Three additional databases (from UK, Netherlands, and Canada) collect PRO-related data upon request.  The majority of databases found to report PRO data are longitudinal and/or cross-sectional, particularly survey data in populations of <200,000.  US, Canadian, and UK databases commonly report PRO data.  Database characteristics vary among PRO categories, including cognitive function, where population type primarily comprises of people from specialty institutions.  CONCLUSIONS: Within 154 database profiles that were reviewed, symptoms and physical function are the most frequently collected PRO data types, while patient satisfaction with care and self-judgments of health are least likely to be found.  Reporting PRO data has become increasingly important for health care; however, this study shows that less than 25% of databases collect any PRO data.