[Cardiovascular risk factors of visitors to a mass-screening booth]

The attitude towards mass screening of serum cholesterol is controversial. In order to characterize the volunteers of such screenings and to test the representativity of its findings, we compared the data of 1686 adult health-screening participants collected during a trade fair in the city of Basel, Switzerland, with the results of two population-based studies, the Basel City Risk Factor Survey and the MONICA Project in Western Switzerland. Among those screened, there was an over-representation of women and older persons. The age-specific medians of blood cholesterol and proportions of hypercholesterolemic persons were consistently higher in female screenees--and marginally so in males--than in the reference populations, whereas higher proportions of persons with ideal cholesterol level in those screened were also observed, especially in younger males. Higher systolic blood pressure, lower relative body weight and less regular smoking were found consistently among the screenees. This cross-sectional study shows that the participants of such mass screening actions are a selective group of older, more frequently female health-conscious persons with a specific risk-factor pattern. Mass screenings of self-selected volunteers can, therefore, not be used for a reliable prediction of risk-factor distributions in the general population. Moreover, suggested further steps for those screenees with both health-conscious behavior and elevated biological risk-factor levels, such as second measurement, medical consultation and counselling, cannot be assured in the setting of a trade fair. The objectives and intentions of such mass screening activities should be reconsidered and discussed.