Screening for depression in primary care with two verbally asked questions: Cross sectional study

Abstract

Objective: To determine the diagnostic accuracy of two verbally asked questions for screening for depression. Design: Cross sectional criterion standard validation study. Setting: 15 general practices in New Zealand. Participants: 421 consecutive patients not taking psychotropic drugs. Main outcome measures: Sensitivity, specificity, and likelihood ratios of the two questions compared with the computerised composite international diagnostic interview. Results: The two screening questions showed a sensitivity and specificity of 97% (95% confidence interval, 83% to 99%) and 67% (62% to 72%), respectively. The likelihood ratio for a positive test was 2.9 (2.5 to 3.4) and the likelihood ratio for a negative test was 0.05 (0.01 to 0.35). Overall, 37% (157/421) of the patients screened positive for depression. Conclusion: Two verbally asked questions for screening for depression would detect most cases of depression in general practice. The questions have the advantage of brevity. As treatment is more likely when doctors make the diagnosis, these questions may have even greater utility.