Management of lung cancer.

Objectives: To analyse the prevalence of lifetime recourse to prostitution (LRP) among men in the general population of Switzerland from a trend and cohort perspective. Methods: Using nine repeated representative cross-sectional surveys from 1987 to 2000, age-specific estimates of LRP were computed. Trends and period effect were analysed as the evolution of cross-sectional population estimates within age groups and overall. Cohort analysis relied on cohorts constructed from the 1989 survey and followed in subsequent waves. Age and cohort effects were modelled using logistic regression and non-parametric monotone regression. Results: Whereas prevalence for the younger groups was found to be logically lower, there was no consistent increasing or decreasing trend over the years; there was no significant period effect. For the 17–30 year age group, the mean estimate over 1987–2000 was 11.5% (range 8.3 to 12.7%); for the 31–45 year group, the mean was 21.5% (range over 1989–2000 20.3 to 23.0%). Regarding cohort analysis, the prevalence of LRP was found to increase steeply in the youngest ages before reaching a plateau near the age of 40 years. At the age of 43 years, the prevalence was estimated to be 22.6% (95% CI 21.1% to 24.1%). Conclusions: The steep increase in the cohort-wise prevalence of LRP in younger ages calls for a concentration of prevention activities in young people. If the plateauing at approximately 40 years of age is not followed by a further increase later in life, which is not known, then consumers of paid sex would be repeat buyers only, a fact that should be taken into account by prevention.