OBJECTIVE: The Zurich study is a longitudinal study in psychiatric epidemiology that started in the late 1970s. The sixth interview in 1999 provides the basis to investigate and update the participation and drop-out patterns of the Zurich subjects. METHOD: Aside from descriptive analyses, particular attention was paid to the Symptom Checklist 90-R (SCL-90-R), used initially to stratify the Zurich sample. RESULTS: The initial proportions of high-scorers vs. low-scorers (two-thirds vs. one-third) have not changed significantly in the 367 subjects who participated in the 1999 interview. More detailed analyses indicate a selective and changing dependence of participation/drop-out on health status as measured by the SCL-90 R. In recent interviews drop-out has become more likely in subjects with extremely high SCL scores and in subjects with low SCL scores. CONCLUSION: Drop-out in the Zurich Study is associated with extreme SCL scores.
OBJECTIVE: The Zurich study is a longitudinal study in psychiatric epidemiology that started in the late 1970s. The sixth interview in 1999 provides the basis to investigate and update the participation and drop-out patterns of the Zurich subjects. METHOD: Aside from descriptive analyses, particular attention was paid to the Symptom Checklist 90-R (SCL-90-R), used initially to stratify the Zurich sample. RESULTS: The initial proportions of high-scorers vs. low-scorers (two-thirds vs. one-third) have not changed significantly in the 367 subjects who participated in the 1999 interview. More detailed analyses indicate a selective and changing dependence of participation/drop-out on health status as measured by the SCL-90 R. In recent interviews drop-out has become more likely in subjects with extremely high SCL scores and in subjects with low SCL scores. CONCLUSION: Drop-out in the Zurich Study is associated with extreme SCL scores.
Authors: Gregor Hasler; Peter J Gergen; David G Kleinbaum; Vladeta Ajdacic; Alex Gamma; Dominique Eich; Wulf Rössler; Jules Angst Journal: Am J Respir Crit Care Med Date: 2005-03-11 Impact factor: 21.405