Increase in recreational drug use between 2008 and 2018: results from a prospective cohort study among HIV-negative men who have sex with men

Aims
To test whether recreational drug use (RDU) and sexualized drug use (SDU) changed in the Amsterdam area between 2008 and 2018 and quantify associations of SDU with condomless anal sex (CAS), recent human immunodeficiency virus (HIV) or sexually transmitted infections (STI) among human immunodeficiency virus (HIV)-negative men who have sex with men (MSM).

Design
Open prospective cohort study.

Setting
Public Health Service of Amsterdam, the Netherlands.

Participants
A total of 976 HIV-negative MSM, aged ≥ 18 years.

Measurements
Self-reported RDU and sexual behaviour in the past 6 months. Laboratory-confirmed HIV and STI (chlamydia, gonorrhoea and syphilis). We studied: any RDU; any SDU (i.e. any RDU during sex); specific SDU (i.e. use of mephedrone, methamphetamine, gamma-hydroxybutyric acid/gamma-butyrolactone, ketamine, amphetamine, cocaine and/or ecstasy during sex); use of individual drugs; and use of individual drugs during sex. We evaluated changes over calendar years in the proportion of individuals with these end-points [using logistic regression with generalized estimating equations (GEE)] and number of drugs (using negative binomial regression with GEE), adjusted for current age, country of birth and education level.

Findings
Median age of participants in 2008 was 33.2 years (interquartile range = 27.8–40.1); 83.1% were born in the Netherlands. The proportion of any RDU increased from 67.2% in 2008 to 69.5% in 2018 [adjusted odds ratio (aOR) = 1.25; 95% confidence interval (CI) = 1.03–1.51]. Any SDU increased from 53.8% in 2008 to 59.8% in 2013 (aOR = 1.23; 95% CI = 1.07–1.42) and remained stable afterwards. Specific SDU increased from 25.0% in 2008 to 36.1% in 2018 (aOR = 2.10; 95% CI = 1.71–2.58). The average number of drugs used increased for those reporting any RDU, any SDU and specific SDU (all P < 0.05. Among those engaging in sex, any SDU was associated with CAS (aOR = 1.36; 95% CI = 1.19–1.55), HIV (aOR = 5.86; 95% CI = 2.39–14.4) and STI (aOR = 2.31; 95% CI = 1.95–2.73). Specific SDU was associated with CAS (aOR = 1.58; 95% CI = 1.37–1.81), HIV (aOR = 6.30; 95% CI = 3.28–12.1) and STI (aOR = 2.15; 95% CI = 1.81–2.55).

Conclusions
Among human immunodeficiency virus (HIV)-negative men who have sex with men in Amsterdam, recreational drug use, including sexualized drug use, increased between 2008 and 2018. Sexualized drug use was strongly associated with condomless anal sex, HIV and sexually transmitted infections.