ON LONGITUDINAL CARIES INDEX DATA - A COMPARISON STUDY BETWEEN COHORTAND CROSS-SECTIONAL ATTEMPTS

The aim of the present study was to compare registered data of caries prevalence and incidence from cross-sectional studies of specified age groups with the corresponding caries data from cohorts of individuals receiving dental health service from the same dental clinic during th e years studied. The study covered two 15-19-year groups, who had been offered complete dental care from three years of age in the City of G oteborg for the time periods 1986/7-1990/1. When compared, the longitu dinal cohort attempts often gave statistically significant different v alues to those of the cross-sectional year classes, which should be co nsidered when presenting caries index mean values in dental health rev iews. It is not indifferent to choose between longitudinal cohort and cross-sectional year class attempts when searching for dental health t reatment effects. Due to the advantages of using longitudinal cohort s tudy methods, and with regard to the differences of the study design u sed, as pointed out in the study, the use of longitudinal cohort patie nt material, extracted from cross-sectional epidemiological data bases , could favour analysis of the effects of different preventive dental care programs.