Characteristics of the recent visitors of the Amsterdam Cohort Studies who participated in an STI screening (N = 197) between 2010–2011 and all visitors (N = 1658) at baseline between December 1985 and 2011.

CSW, commercial sex worker; IQR, interquartile range; STI, sexually transmitted infection.aSupervised: living in a hotel/pension, institutional care, lodging.bPartner type: per individual more than 1 partner type possible.cUnprotected sex: Inconsistent condom use.dIncludes injecting and noninjecting drug use; per individual more than 1 type of drug use possible.eHeroin and cocaine together.fIncludes benzodiazepines, amphetamines and barbiturates.#Questions on sexual risk behaviour were available from 1991 onwards.*Questions on partner types and cannabis use were only available from 2009 onwards.