[1] Univ Manitoba, Coll Nursing, Winnipeg, MB R3T 2N2, Canada
[2] Univ Manitoba, Coll Med, Fac Hlth Sci, Dept Community Hlth Sci, Winnipeg, MB R3T 2N2, Canada
[3] Univ Manitoba, Coll Med, Fac Hlth Sci, Dept Obstet Gynecol & Reprod Sci, Winnipeg, MB R3T 2N2, Canada
[4] McMaster Univ, Fac Hlth Sci, Sch Nursing, Hamilton, ON L8S 4K1, Canada
[5] McMaster Univ, Fac Hlth Sci, Dept Clin Epidemiol & Biostat, Hamilton, ON L8S 4K1, Canada
[6] McMaster Univ, Gilbrea Ctr Studies Aging, Hamilton, ON L8S 4M4, Canada
[7] Univ Calgary, Fac Med, Dept Paediat, Calgary, AB T3B 6A8, Canada
[8] Univ Calgary, Fac Med, Dept Community Hlth Sci, Calgary, AB T3B 6A8, Canada
[9] Univ British Columbia, Sch Populat & Publ Hlth, Vancouver, BC V6N 1Z3, Canada
[10] Dalhousie Univ, Dept Obstet & Gynecol, IWK Hlth Ctr, Halifax, NS B3K 6R8, Canada
[11] Univ Alberta, Fac Nursing, Edmonton, AB T6G 1C9, Canada
[12] McMaster Univ, Fac Hlth Sci, Dept Obstet & Gynecol, Hamilton, ON L8S 4K, Canada
[13] McMaster Univ, Fac Hlth Sci, Dept Clin Epidemiol & Biostat, Hamilton, ON L8S 4K, Canada