[1] Univ Ghent, Dept Publ Hlth & Primary Care, Interuniv Ctr Hlth Econ Res I CHER, Corneel Heymanslaan 10, B-9000 Ghent, Belgium
[2] Katholieke Univ Leuven, Dept Pharmaceut & Pharmacol Sci, Here Str 49,O&N2 Bus 521, B-3000 Leuven, Belgium
[3] Vrije Univ Brussel, Interuniv Ctr Hlth Econ Res I CHER, Dept Publ Hlth, Laarbeeklaan 103, B-1090 Brussels, Belgium
[4] Katholieke Univ Leuven, Dept Movement Sci, Tervuursevest 101,POB 1500, B-3001 Leuven, Belgium
[5] Katholieke Univ Leuven, HIVA Res Inst Work & Soc, Park Str 47,POB 5300, B-3000 Leuven, Belgium