1. From Public Health (C.J., D.F.M., R.S., J.P.P.), University of Glasgow, United Kingdom; West of Scotland Regional Heart and Lung Centre (K.G.O., K.P.J.), Golden Jubilee National Hospital, Glasgow, United Kingdom; Monklands Hospital (R.S.), Airdrie, United Kingdom; Royal Infirmary (A.C.H.P.), Edinburgh, United Kingdom; Aberdeen Royal Infirmary (A.D.F.), Aberdeen, United Kingdom; and Ninewells Hospital (H.E.), Dundee, United Kingdom.