Sexual health and behavior of young people in Switzerland

1.1 Introduction
Improving sexual and reproductive health is a public health priority, and the timing of first sexual intercourse and the context in which it occurs both have health implications. Moreover, information and monitoring about sexual behavior is essential to the design and assessment of interventions to improve sexual health. The last survey centered on the sexual and reproductive health of adolescents/young adults in Switzerland was carried out in 1995. Since then, all data on the subject come from general surveys. As contextual factors, the life contexts of youths explain a large amount of the variance in sex related behaviors, and a fair amount of new developments have appeared in the last twenty years that might have had an impact on youth’s sexual behavior: AIDS has gone from a fatal to a chronic condition, there has been a liberalization of the access to emergency contraception, Swiss law changed in 2002 and allowed abortion in the first 12 weeks of pregnancy, the HPV vaccine is recommended as part of the vaccination program (for girls since 2008 and for boys since 2016), sildenafil citrate (e.g. Viagra®) has appeared on the market as a treatment for erectile dysfunction, pornography has become extremely accessible and free, phenomena of online sex and sexting have emerged. These changes might have an impact on adolescent sexual behaviors although we do not know how and to what extent. This survey provides self-reported information from young adults in Switzerland. The primary objective was to obtain current epidemiological data on young people’s sexual and reproductive health and behaviors.
1.2 Methods
The survey comprised three parts: two of them contained questions on socio-demographic characteristics of the participants (part 1) and on their sexual and health behavior (part 3), and one part was a life history calendar (LHC, part 2). In the LHC, participants were asked to identify the period of occurrence of different life events. The aim of the LHC was to facilitate recollection and dating of personal events by referencing each of them to other key events or milestones of their life (e.g. moving to a new residence or obtaining one’s drive licence). The initial sample was provided by the Swiss Federal Office of Statistics, and it was representative of the entire population living in Switzerland in terms of sex, language, and canton of residence. This sample included 49’798 individuals aged between 24 and 26 years old on 30 September 2016 (birthdate between 01 October 1989 and 30 September 1992). Starting on the 8th June 2017, a first invitation letter was sent to 10’000 individuals. To ensure the operation of the server and allow adjustments in case of problems, the remaining letters (39’798) were sent in two different waves (9 June and 30 June). Depending on the canton of residence, the letter was sent either in French and German, or in Italian and German. The initial goal was to obtain 10’000 answers, but it rapidly appeared that respondents were more reluctant than anticipated to participate in the survey. Moreover 2’402 (4.8%) letters were returned by the postal service, 12 (0.02%) e-mails were sent by parents or caregivers to inform that the person was disabled, had gone abroad or did not speak one of the three languages and 16 (0.03%) letters were returned by participants themselves to say that they did not want to participate. In September 2017, it was decided to send a reminder to 10’000 people randomly chosen among the ones having not answered yet and not being part of the returned letters. Data collection ended on 26 November 2017. The final sample included 7’142 people aged between 24 and 26 years and living in Switzerland at the time of the addresses delivery (30 September 2016). This corresponds to a response rate of 15.1%. Among them 5’618 individuals completed the entire questionnaire or a significant part of it (11.9%, or 78.7% of all respondents). After computing the distribution of the main socio-demographic variables available in the survey and for which the true population-level distribution was known, we had to correct the sample distribution using weights for two characteristics: sex and canton of residence because females from the French part of Switzerland were overrepresented in the participants. Weights were computed for those who abandoned during the third part of the questionnaire and those who completed it until the end (even if they omitted some questions).
1.3 Results

1.4 Conclusions
Overall, youth in Switzerland report a healthy sexuality. However, young people being active on online sex need to be further analyzed regarding both the frequency of this practice and the potential risk they incur in. Unfortunately, women continue to be overrepresented in the cases of unwanted sexual experiences and sexual abuse. Contrary to popular belief, sexual dysfunctions are relatively common among young people. There is a sizeable percentage of youth who have exchanged sexual favors for money, goods or services, who have had sexual relationships while intoxicated or group sex. Reliable contraceptive / protective use is the norm in this age group and it varies from first to last intercourse. Male condom and hormonal contraception are the most used by far. Emergency contraception is a clear option in cases when the main contraceptive method failed. However, even if the condom use rate is quite high, even at last intercourse, the reported STI rate of 10% is relatively high compared to other studies and needs further analysis.