National Institute on Aging10.13039/100000049R01-AG060949Penn State Population Research InstituteEunice Kennedy Shriver National Institute of Child Health and Human Development10.13039/100009633P2C-HD041025Government of Canada10.13039/501100000023Canadian Institutes of Health Research10.13039/501100000024MYB-150262Social Sciences and Humanities Research Council of Canada10.13039/501100000155435-2017-0618890-2016-9000National Institutes of Health10.13039/100000002T32HD007514