Yield and costs of direct and stepped screening for depressive symptoms in subjects aged 75 years and over in general practice

Abstract

To examine yield and costs of two screening methods for depressive symptoms in subjects ≥75 years in general practice. In 73 general practices of 12.144 registered subjects ≥75 years 10.681 could be invited for screening. In the first 31 practices we invited 3797 subjects for direct screening which implied an invitation by letter followed by a home visit to administer the 15-item Geriatric Depression Scale (GDS-15). In the remaining 42 practices 6884 subjects were invited for stepped screening which implied that the GDS-15 was sent by post, followed by a home visit only if the self-administered GDS-15-score was ≥4 points. Being screen-positive for depressive symptoms was defined as an interviewer-administered GDS-15-score ≥5 points. Screening costs were estimated based on results in this study. Of all registered subjects 707 (5.8%) were already being treated for depression. The yield of direct screening was higher than of stepped screening (2.6% versus 1.9%, p = 0.009), with similar yields for subjects aged 75-79 years and for subjects aged ≥80 years. In a standard GP-practice with 160 subjects ≥75 years estimated total screening costs are about twice as high for direct screening than for stepped screening. Estimated costs per screen positive subject are €350 for direct screening and €250 for stepped screening. Direct screening has a higher yield, but is also more time consuming and more expensive. Whether the extra yield is clinically relevant and worth the extra costs, will depend on the subsequent treatment effect. www.controlled-trials.com/ISRCTN 71142851