[Vasectomy in Quebec: 1977-1997].

Vasectomy is recognized as an efficient method of contraception. However, some recent findings have suggested that vasectomy may raise a potential health risk, notably related to prostate cancer. The goal of the present study is to evaluate the spatial and temporal evolution of this surgical practice in Québec (Canada). Using the registry of the Régie de l'assurance-maladie du Québec, we describe the course of vasectomy practice during the past 21 years. We also estimate the frequency of vasectomy procedures on the regional scale. Observed and expected rates of vasectomy and a synthetic index of vasectomy allow us to evaluate its spatial and temporal evolution. The results show a similar annual growth rate of this practice during the last 10 years. The mean age at the time of vasectomy of the study subjects (N = 332,000) is 35 years old. However recently, this mean age seems to be more representative because of the lower proportions of younger (< 25 years old) and older (> 50 years old) patients at the time of vasectomy. In addition, we observe some clear differences concerning the vasectomy rates between specific geographical sectors; the rates being significantly lower (p < 0.01) in urban and some rural areas. The highest rates are found in the suburbs of Montréal and Québec City. There are also some local variations of the practice, which are difficult to interpret. In this article, we compare our results to those for the rest of Canada and the United States. We note that the rates are generally similar to those for the Province of Québec. Besides, we discuss about the reasons for strong spatial variations of the surgery.