Telephone surveys as an alternative for estimating prevalence of mental disorders and service utilization: a Montreal catchment area study.

BACKGROUND Large-scale mental health surveys have provided invaluable information regarding the prevalence of specific mental disorders and service use for mental health reasons. Unfortunately, because vast surveys conducted face to face are very costly, many countries and provinces do not embark upon this path of research, thus depriving themselves of a rich source of data useful for service planning. METHOD As an alternative, the authors undertook a telephone survey with a sample of 893 residents from a Montreal catchment area. Mental disorders were assessed by the Composite International Diagnostic Interview Simplified (CIDIS), an instrument especially designed to be used in mail or telephone surveys. Service utilization was measured by an instrument similar to those used in recent large Canadian or American surveys. RESULTS The prevalence rate for any mental disorder was lower in this study than in some large-scale epidemiological surveys reviewed. This could be explained by methodological differences, such as number of disorders covered and period of reference. With regard to specific mental disorders, results appeared very similar to those of other studies. Concerning service utilization, rates tended to be higher than in other studies, and this finding could reflect real differences between Quebec and other Canadian provinces or the United States. CONCLUSIONS Aside from being lower in cost, telephone surveys can yield results comparable to those obtained in large-scale epidemiological surveys conducted by means of face-to-face interviews.