Objective: To analyse the psychometric properties of the Whooley questions and the 21-item Beck Depression Inventory (BDI-21) in older adults with depression and chronic health problems.
Design: A population-based study.
Setting: Community.
Subjects: 474 adults, aged 72-73 years, living in the city of Oulu, Finland.
Main outcome measures: The screening parameters of the Whooley questions and the BDI-21 for detecting major depression.
Results: The prevalence of major depression according to the DSM-IV was 5.3% (single or recurrent episode) obtained by the Mini Neuropsychiatric Interview (MINI). The BDI-21 was best able to identify a current episode of major depression with a cut-off point of 11. The sensitivity and specificity of this cut-off point were 88.0% (95% confidence interval (95% CI) 68.8-97.5) and 81.7% (95% CI 77.8-85.2), respectively. The area under the receiver operating characteristics (ROC) curve was 0.89 (95% CI 0.83-0.96). The two Whooley screening questions had a sensitivity of 62.5% (95% CI 40.6-81.2) and either screening question plus the help question had a sensitivity of 66.7% (44.7-84.4).
Conclusions: The Beck Depression Inventory is a valid instrument for the diagnosis of depression in older adults. As a screening measure, the optimal cut-off score should be 11 or higher. Our results indicate that the sensitivity of the Whooley questions is not high enough to be used as a screening scale among the elderly.