[1] Maastricht Univ, CAPHRI Sch Publ Hlth & Primary Care, Fac Hlth Med & Life Sci, Dept Epidemiol, POB 616, NL-6200 MD Maastricht, Netherlands
[2] Maastricht Univ, CAPHRI Sch Publ Hlth & Primary Care, Fac Hlth Med & Life Sci, Dept Social Med, Maastricht, Netherlands