RT Journal Article SR Electronic T1 Objective measurement of physical activity: improving the evidence base to address non-communicable diseases in Africa JF BMJ Global Health FD BMJ Publishing Group Ltd SP e001044 DO 10.1136/bmjgh-2018-001044 VO 3 IS 5 A1 Barr, Anna Louise A1 Young, Elizabeth H A1 Sandhu, Manjinder S YR 2018 UL http://gh.bmj.com/content/3/5/e001044.abstract AB