Revista de Saúde Pública
On-line version ISSN 1518-8787
Print version ISSN 0034-8910
SANTOS, JL et al. Incidence rate and spatio-temporal clustering of type 1 diabetes in Santiago, Chile, from 1997 to 1998. Rev. Saúde Pública [online]. 2001, vol.35, n.1, pp.96-100. ISSN 1518-8787. http://dx.doi.org/10.1590/S0034-89102001000100014.
OBJECTIVE: To estimate the incidence rate of type 1 diabetes in the urban area of Santiago, Chile, from March 21, 1997 to March 20, 1998, and to assess the spatio-temporal clustering of cases during that period. METHODS: All sixty-one incident cases were located temporally (day of diagnosis) and spatially (place of residence) in the area of study. Knox's method was used to assess spatio-temporal clustering of incident cases. RESULTS: The overall incidence rate of type 1 diabetes was 4.11 cases per 100,000 children aged less than 15 years per year (95% confidence interval: 3.06¾5.14). The incidence rate seems to have increased since the last estimate of the incidence calculated for the years 1986¾1992 in the metropolitan region of Santiago. Different combinations of space-time intervals have been evaluated to assess spatio-temporal clustering. The smallest p-value was found for the combination of critical distances of 750 meters and 60 days (uncorrected p-value = 0.048). CONCLUSIONS: Although these are preliminary results regarding space-time clustering in Santiago, exploratory analysis of the data method would suggest a possible aggregation of incident cases in space-time coordinates.
Keywords : Diabetes mellitus, insulin-dependent [epidemiology]; Space-time clustering; Incidence; Child; Adolescence; Urban zones.