[1] Populat Hlth Res Inst, Hamilton, ON, Canada
[2] McMaster Univ, Hamilton, ON, Canada
[3] Univ Western Ontario, London Hlth Sci Ctr, London, ON, Canada
[4] Dalhousie Univ, Halifax, NS, Canada
[5] Cleveland Clin, Cleveland, OH 44106 USA
[6] Maine Med Ctr, Portland, ME 04102 USA
[7] Wake Forest Univ, Winston Salem, NC 27109 USA
[8] Univ Toronto, Sunnybrook Hlth Sci Ctr, Toronto, ON, Canada
[9] Univ Calgary, Calgary, AB, Canada
[10] All India Inst Med Sci, New Delhi, India
[11] Chinese Univ Hong Kong, Hong Kong, Hong Kong, Peoples R China