Funding for this research was provided by:
Economic and Social Research Council (ES/M010317/1)
National Institute on Aging (R01AG048835)
Medical Research Council (MR/M009351/1, MC_UU_12019/1, MC_UU_12019/2, MR/M020894/1, MC_UU_12013/5, MC_UU_12013/9])
Received: 3 March 2017
Accepted: 22 August 2017
First Online: 7 September 2017
Ethics approval and consent to participate
: Ethical approval for the study was obtained from the Greater Manchester Local Research Ethics Committee and the Scotland A Research Ethics Committee.
: Not applicable
: The authors have no conflicts of interest to disclose.
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