On the incidence and sex ratio of transsexualism in Sweden, 1972-2002.

The purpose of this study was to investigate whether the incidence of transsexualism in Sweden has been stable over the period of the three decades sex reassignment has been permitted by law in Sweden and whether there has been a change over time in the sex ratio of those requesting sex reassignment surgery (SRS). The incidence and sex ratio of transsexualism were calculated on the basis of the total number of applications for sex reassignment submitted to the National Board of Health and Welfare between July 1972 and June 2002. The frequency data were then analyzed in relation to the number of SRSs performed, age at the time SRS was requested, and the proportion of applicants of foreign origin. The results showed that the incidence of transsexualism was not stable during the study period of three decades. The sex ratio changed from almost 1:1 in the late 1960s to almost 2:1 in favor of male-to-female (MF) transsexuals in the 1990s. The number of SRSs performed rose considerably after the mid- 1980s. On average, MF transsexuals are now 6 years older than female-to-male (FM) transsexuals when they apply for SRS, and MF transsexuals are currently about 8 years older at the time of application than they were 20 years ago. The proportion of applications from applicants of foreign origin increased during the 1990s.