[1] Univ Basque Country, UPV EHU, Dept Clin & Hlth Psychol & Res Methods, Ave Tolosa 70, Donostia San Sebastian 20018, Spain
[2] Bradford Royal Infirm, Bradford Inst Hlth Res, Temple Bank House,Duckworth Lane, Bradford BD9 6RJ, England
[3] Inst Salud Carlos III, Spanish Consortium Res Epidemiol & Publ Hlth CIBER, C Monforte De Lemos 3-5, Madrid, Spain
[4] Biogipuzkoa Hlth Res Inst, Grp Environm Epidemiol & Child Dev, Paseo Doctor Begiristain S-N, Donostia San Sebastian 20014, Spain
[5] UCL, Bartlett Sch Architecture, London WC1H 0QB, England
[6] Univ York, Dept Hlth Sci, York YO10 4DD, England
[7] Univ York, Hull York Med Sch, York YO10 5DD, England