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.