Comparison between the use of oral contraceptives and the incidence of surgically confirmed gallstone disease.

A causal relationship between the use of oral contraceptives and gallstone disease has been proposed. If this is true, it is reasonable that the incidence of cholecystectomy in women of exposed ages should increase. In the present study a statistical analysis of the change in the incidence of cholecystectomy in women between 1961, i.e. 4 years before, and 1971, i.e. 6 years after, the introduction of oral contraceptives in Sweden was performed. To delimit uncontrolled factors, such as diet and attitude towards surgery, the change in incidence of cholecystectomy in women was compared with the corresponding change in men during these years. The results indicate an increased incidence of cholecystectomy in women in age groups exposed to oral contraceptives. These findings support a causal relationship between the use of oral contraceptives and the incidence of gallstones in the population.