[1] Karolinska Inst, Dept Publ Hlth Sci, S-17177 Solna, Sweden
[2] Univ Limerick, Dept Phys Educ & Sport Sci, Limerick, Ireland
[3] Univ Limerick, Hlth Res Inst, Limerick, Ireland
[4] South London & Maudsley NHS Fdn Trust, Physiotherapy Dept, Denmark Hill, London SE5 8AZ, England
[5] Kings Coll London, Inst Psychiat Psychol & Neurosci, Dept Psychol Med, De Crespigny Pk, London SE5 8AF, England
[6] Karolinska Inst, Dept Med Epidemiol & Biostat, Solna, Sweden
[7] Univ Milano Bicocca, Dept Stat & Quantitat Methods, Milan, Italy
[8] Karolinska Univ, Hosp Huddinge, Clin Endocrinol Metab & Diabet, Dept Med, Stockholm, Sweden
[9] Karolinska Inst, Dept Med, Clin Epidemiol Unit, S-17177 Solna, Sweden