[1] Univ Ottawa, Ottawa Hosp, Res Inst, Populat Hlth Program, Ottawa, ON, Canada
[2] Univ Quebec Trois Rivieres, Dept Chiroprat, Trois Rivieres, PQ, Canada
[3] Clin Epidemiol Program, Ottawa, ON, Canada
[4] Univ Aberdeen, Hlth Psychol Grp, Aberdeen, Scotland
[5] Univ Aberdeen, Hlth Serv Res Unit, Aberdeen, Scotland
[6] Univ Michigan, Sch Nursing, Ann Arbor, MI 48109 USA
[7] VA Ann Arbor Hlth Care Syst, Ctr Clin Management Res, Ann Arbor, MI USA
[8] Univ Ottawa, Fac Med, Ottawa, ON, Canada