Prevalence of Illegal Drug Use in Belgium

"The most recent published results of the BHIS on psychoactive substance use date from 2008 (Gisle, L., 2010; Gisle, L., 2010;Van der Heyden et al., 2010; Van der Heyden et al., 2010). The results of this national general population survey (N= 11,026 for the drugs section; 15-64y) are described in detail in the 2011 Belgian Annual Report (Deprez et al., 2012). In 2013, the Surveys, Lifestyle and Chronic Diseases (SLCD) research group of the Scientific Institute of Public Health (WIV-ISP) performed the data collection of a new BHIS. Different from previous waves, the 2013 BHIS used the computer-assisted personal interviewing (CAPI) method for the face-to-face part of the questionnaire, although drug use is still surveyed by the use of a self-completion part. The researchers maintained the same substance-related items of the 2008 survey, being the lifetime, last year and last month cannabis use; frequency of last month cannabis use; the age of first time cannabis use and the last year use of cocaine, amphetamines, ecstasy, LSD, heroin, methadone and buprenorphine. New for the 2013 BHIS is the inclusion of information on ‘legal highs’. Results for the 2013 BHIS are expected by the end of 2014.
"However, it is worth noting that the prevalence for illicit substance use (15-64 years old persons) found in general surveys, such as the BHIS, are probably underestimated, especially for drugs other than cannabis. Marginalized people (homeless, prisoners, institutionalized persons) are excluded from the sample because invitations to participate to this study are sent only to households after a prior phone contact. The self-completion questionnaire related to substance use is only filled out after having received the visit of the interviewer (Van der Heyden et al., 2010;Van der Heyden et al., 2010). It is highly likely that "hard" or “severe” users do not accept to receive the interviewer at home and/or do not take the time to complete the questionnaire (Demarest et al., 2012)."