[1] Karolinska Inst, Dept Med, Clin Epidemiol Unit, Stockholm, Sweden
[2] Karolinska Inst, Dept Med, Resp Unit, Solna, Sweden
[3] Karolinska Univ Hosp, Stockholm, Sweden
[4] Karolinska Inst, Dept Med, Clin Epidemiol Unit, Solna, Sweden
[5] Karolinska Inst, Dept Med, Rheumatol Unit, Solna, Sweden