Howren A, et al. - In order to define the use of administrative health databases to examine depression and anxiety in patients with rheumatic diseases and to synthesize the case definitions that have been used, researchers undertook this systematic review. They analyzed 36 studies identified from Medline, Embase, CINAHL, Cochrane Database of Systematic Reviews, and PsychINFO, which reported depression and anxiety in people with rheumatic diseases, used administrative health data, and mentioned case definitions for depression and anxiety using ICD codes. Operational definitions were described by 24 studies, and claims from more than one type of administrative data source (eg, inpatient, outpatient) were integrated by 19 (79.2%) of these studies. Six (16.7%) studies utilized validated case definitions, with sensitivity estimates for depression and anxiety case definitions ranging from 33%-74% and 42%-76%, respectively. Many case definitions employed to assess depression and anxiety in people with rheumatic diseases, within administrative health databases, were found in this study. Case definitions with shown validity should be used and case definitions within multiple data sources should be operationalized.