Can routine information improve case finding of depression among 65 to 74 year olds in primary care?

The identification of groups with higher prevalence of major depression allows for more cost-effective investigation and treatment.

The aim of this study was to examine whether the identification of patient groups with a higher prevalence of depression through information routinely available in primary care can increase the efficiency of active case finding.

A cross-sectional two-stage survey was carried out of 2633 community residents between the age of 65 and 74 consisting of a structured interview with concurrent audit of general practice records. The 15-item geriatric depression scale (GDS-15) was used as a screening tool for depression. Individuals scoring > or =4 on the GDS-15 were offered a clinical interview using the Schedules for Clinical Assessment in Neuropsychiatry (SCAN).

There were 1912 (72.6%) participants in the first stage interview, of whom 134 had GDS-15 scores > or =4 and were invited to take part in the second stage. Of these, 90 participants (67.2%) agreed to the clinical interview. To detect one case of major depression, the number needing to be assessed was 63 for the whole sample. The number needing to be assessed was lower among those receiving antidepressants (nine), frequent GP attenders (12) and those living alone (32).

Although depression is more common among various subgroups, our data show that the investigation of each high prevalence subgroup would detect only a minority of all cases in the total population. It is not possible to rely on active case finding in high prevalence subgroups for a high detection rate of depression in a practice population.