Evaluation of the feasibility, reliability and diagnostic value of shortened versions of the geriatric depression scale.
BACKGROUND: Many scales have been developed to assess depression, but they are often too lengthy to be of practical use in general practice consultations. AIM: A study was undertaken to investigate the feasibility, reliability and diagnostic value of the geriatric depression scale and its shorter versions for screening in general practice. METHOD: A total of 586 consecutive consulting patients aged 65 years and over were studied in nine general practices in the west of the Netherlands (13 doctors). The 30-item version of the geriatric depression value was compared with the diagnostic interview schedule as a reference test. RESULTS: The reference test indicated a major depression in six patients while 27 patients had a dysthymic disorder (that is, a chronic mild depression). Five per cent of patients required help for 50% of the questions on the geriatric depression scale. The diagnostic value of the 30-item, 15-item, 10-item and four-item versions did not differ significantly, but the one-item version performed no better than chance. Two items discriminated best between patients who were and who were not depressed (P < 0.05), only one of which was included in a previously proposed four-item version of the scale. The reliability of the proposed four-item version was 0.64, the reliability of the other versions ranging from 0.70 to 0.87. CONCLUSION: The results for the different versions of the geriatric depression scale suggest the use of a 10-item or a four-item version. For practical purposes, the smallest subset would be the most desirable: the four-item version. These scales may be better suited for exclusion rather than inclusion purposes. The feasibility of screening for depression in elderly people in a general practice setting is discussed in the light of the results of the study.