Evaluating a household survey measure of psychic distress

This paper describes a study to assess the validity of a brief household survey measure of psychic distress (PSYDIS). The measure classifies persons according to their pattern of scores on four dimensions, including anxiety and depression. Study subjects were interviewed first as respondents from the general population in a cross-sectional household survey. Then, according to their ratings on PSYDIS, subsamples were selected for psychiatric evaluation in a clinic a few weeks later. The survey ratings of 287 persons were compared with evaluations of the same persons by experienced psychiatrists. Overall levels of concordance ranged from 76% to 80%, depending on the psychiatric criterion used. Concordance was very high for women; it was lower for men and for persons classified as High on PSYDIS. We than applied two analytic strategies for increasing agreement between the clinical judgements and the clinical ratings. Strategy number I augmented the symptom checklist data with additional survey data on the subject's history of episodes of distress. Strategy II revised procedures for constructing the PSYDIS typology by (1) using more rigorous cutting point scores on the component scales, and (2) using a non-typological method of classification. The first strategy improved agreement between the clinic and survey measures; the second did not. The paper also compares PSYDIS with other brief symptom checklist measures.