S E Birnie | PubMed Health

PubMed1994

The geographic variation of cancer incidence in Ontario.

OBJECTIVES: Our objectives were (1) to describe an analysis of the spatial pattern of cancer incidence in Ontario and (2) to discuss the quality of data in the Ontario Cancer Registry with respect to the accuracy of local cancer rates. METHODS: Cancer incidence rates were calculated for 22 cancer sites in 49 counties of Ontario during 1976 to 1986. Capture-recapture methods were used to estimate completeness of case registration, and completeness of residence information was also assessed. Spatial autocorrelation was used in measuring the geographic pattern of incidence rates. Comparisons were also made between sexes and with earlier data from 1966 to 1975. RESULTS: The quality of the geographic data in the registry appeared good, and corrections for incomplete or inaccurate registration had little impact. About one third of the sex-site combinations showed some evidence of spatial patterning in the cancer rate. Particularly strong regional variation was noted for cancers of the stomach, lung, uterus, and prostate. CONCLUSIONS: The analysis revealed a number of cancers with significant spatial patterning of risk. Further work is needed to relate the cancer data to other information on potential life-style and environmental factors.

Female↗

PubMed1991

Mapping mortality and morbidity patterns: an international comparison.

A set of 49 national, intranational and international health atlases was surveyed to characterize their mapping methodology with respect to the populations covered, the diseases represented, the mapping techniques, and statistical methods. Little consistency was found concerning the choice of data function to be mapped, minimum event frequency requirements, method of age standardization, or map colour systems. Many atlases did not include basic epidemiological information; for instance, approximately half the atlases did not quote population denominators. There was a tendency to emphasize statistical significance over rate values, and to focus on high rather than low risk. Very few atlases included supplemental information on environmental factors. Most adopted a descriptive stance, and attempted no aetiological interpretation. We conclude that inter-atlas comparisons are made very difficult by methodological differences, and that even regional comparisons within atlases should be made cautiously. We propose a set of methodological guidelines for consideration in future atlases.

Epidemiology↗