**4.3 Patterns of alcohol use and other substance use**

Alcohol use in previous months (average number of units per week day [Monday– Thursday] and average number of units per weekend day [Friday–Sunday]), regular drinking places (parents' home, adolescents' own home, friends' home, on the street, work place, at [a] school [party], public place [sports bar/canteen], commercial place [hotel and catering industry/bar/pub/discotheque], holiday, other), regular (illicit) substance use (none, cannabis, cocaine, amphetamines/speed, magic mushrooms, Ecstasy [3,4 methylenedioxymethamphetamine, or MDMA], other), regular tobacco use (no, yes; if possible, estimated number of cigarettes per week), prescribed medication use (no, yes; if yes, what type of medication/name], and parental knowledge of alcohol use (parents know exactly, parents know approximately, parents believe their adolescent child consumes more or less), age of first alcoholic drink.
