RT Journal A1 Sarrazin M, Rosenthal GE T1 LImitations of administrative databases—reply JF JAMA JO JAMA YR 2012 FD June 27 VO 307 IS 24 SP 2589 OP 2590 DO 10.1001/jama.2012.6636 UL http://dx.doi.org/10.1001/jama.2012.6636 AB Administrative data are a source of information regarding real-world clinical practices across geographic regions, hospitals, and important patient subgroups (eg, race, payer) and have variations that are difficult to assess using data from randomized clinical trials, surveys, or other primary data sources. Thus, creative approaches to enhancing administrative data are needed. As Haut et al note, the lack of complete clinical information in administrative data can be addressed, in part by supplementing administrative data with information available through electronic health records or existing registries, such as the SEER cancer registry. Often the administrative data can be significantly improved with only 1 or 2 additional variables. For example, Hannan et al1 showed that the inclusion of 3 additional variables obtained from a clinical registry (ejection fraction, reoperation, and >90% narrowing of the left main coronary artery) significantly improved the discrimination of coronary bypass surgery risk-adjustment models based on administrative data. As another example, Pine et al2 showed that the predictive validity of risk adjustment models for 6 common diagnoses derived from administrative data and electronically available laboratory data were similar to models derived from data painstakingly abstracted from patients' medical records.