[1] Univ Amsterdam, Acad Med Ctr, Div Clin Methods & Publ Hlth, Dept Gen Practice, NL-1105 AZ Amsterdam, Netherlands
[2] Univ Amsterdam, Acad Med Ctr, Div Clin Methods & Publ Hlth, Dept Publ Hlth, NL-1105 AZ Amsterdam, Netherlands
[3] NYU, Sch Med, Dept Med, Ctr Healthful Behav Change,Div Gen Internal Med, New York, NY 10016 USA