RT Journal Article SR Electronic T1 What matters, when, for whom? three questions to guide population health scholarship JF Injury Prevention JO Inj Prev FD BMJ Publishing Group Ltd SP i3 OP i6 DO 10.1136/injuryprev-2017-042415 VO 24 IS Suppl 1 A1 Sandro Galea A1 Katherine M Keyes YR 2018 UL http://injuryprevention.bmj.com/content/24/Suppl_1/i3.abstract AB