CASE-FINDING INSTRUMENTS FOR DEPRESSION - 2 QUESTIONS ARE AS GOOD AS MANY

OBJECTIVE: To determine the validity of a two-question case-finding in strument for depression as compared with six previously validated inst ruments. DESIGN: The test characteristics of a two-question case-findi ng instrument that asks about depressed mood and anhedonia were compar ed with six common case-finding instruments, using the Quick Diagnosti c Interview Schedule as a criterion standard for the diagnosis of majo r depression. SETTING: Urgent care clinic at the San Francisco Departm ent of Veterans Affairs Medical Center. PARTICIPANTS: Five hundred thi rty-six consecutive adult patients without mania or schizophrenia. MEA SUREMENTS AND MAIN RESULTS: Measurements were two questions from the P rimary Care Evaluation of Mental Disorders patient questionnaire, both the long and short forms of the Center for Epidemiologic Studies Depr ession Scale, both the long and short forms of the Beck Depression Inv entory, the Symptom-Driven Diagnostic System for Primary Care, the Med ical Outcomes Study depression measure, and the Quick Diagnostic Inter view Schedule. The prevalence of depression, as determined by the stan dardized interview, was 18% (97 of 536). Overall, the case-finding ins truments had sensitivities of 89% to 96% and specificities of 51% to 7 2% for diagnosing major depression. A positive response to the two-ite m instrument had a sensitivity of 96% (95% confidence interval [CI], 9 0-99%) and a specificity of 57% (95% CI 53-62%). Areas under the recei ver operating characteristic curves were similar for all of the instru ments, with a range of 0.82 to 0.89. CONCLUSIONS: The two-question cas e-finding instrument is a useful measure for detecting depression in p rimary care. It has similar test characteristics to other case-finding instruments and is less time-consuming.