Community-based surveillance of cardiovascular risk factors in Geneva: methods, resulting distributions, and comparisons with other populations.

OBJECTIVES: This paper presents the results of an ongoing community-based surveillance program of cardiovascular risk factors in Geneva, Switzerland, using percentiles with their associated 95% confidence intervals and compares the Genevan results with published data from international surveys reporting percentiles.
METHODS: A random survey of adults ages 35 to 74 years was conducted from 1993 to 1994. Confidence intervals for percentiles based on parametric and non-parametric methods are given.
RESULTS: The distribution of total cholesterol was shifted upward with increasing age. The median reached a maximum at 55-64 years among men (5.7 mmol/L) and at 65-74 years among women (5.9 mmol/L), and remained relatively stable thereafter. In both genders, systolic and, less so, diastolic blood pressure increased progressively with advancing age. The median daily energy intake among men declined from 2,390 kcal at age 35-44 years to 2,169 kcal at age 65-74 years, while among women it remained stable at about 1,900 kcal. In both males and females, the relative intake of saturated fat was stable throughout life (14 to 13%). The median body mass index (BMI) was about 25 kg/m2 across all age groups among men, but increased with age among women, with a peak of 23.6 kg/m2 occurring at ages 65-74 years. Compared with U.S. and western European surveys, Genevan men and women had lower total plasma cholesterol and Genevan women tended to have lower BMIs.
CONCLUSIONS: Percentiles with their associated precision appear particularly well suited for international comparison of surveillance data. They could be used in the future to monitor shifts in distributions resulting from mass prevention strategies.