[1] Univ Southampton, Primary Care & Populat Sci Div, Southampton, Hants, England
[2] Univ Med Ctr Utrecht, CAHP, Fac Social & Human Sci, Utrecht, Netherlands
[3] Univ Med Ctr Utrecht, Julius Ctr Hlth Sci & Primary Care, Utrecht, Netherlands
[4] Cardiff Univ, Sch Med, Cochrane Inst Primary Care & Publ Hlth, Cardiff CF10 3AX, S Glam, Wales
[5] Cardiff Univ, Sch Med, South East Wales Trials Unit, Cardiff CF10 3AX, S Glam, Wales
[6] Med Univ Lodz, Dept Family & Community Med, Lodz, Poland
[7] Pomeranian Med Univ, Independent Lab Family Physician Educ, Szczecin, Poland
[8] Ely, Ely Bridge Surg, Cardiff, S Glam, Wales
[9] August Pi & Sunyer Univ Barcelona Ciber Enfermeda, Barcelona Insitut Invest Biomed, Hosp Clin, Pneumol Dept,Clin Inst Thorax, Barcelona, Spain
[10] Univ Antwerp, Ctr Gen Practice, B-2020 Antwerp, Belgium
[11] Univ Antwerp, Lab Med Microbiol, B-2020 Antwerp, Belgium
[12] Univ Antwerp, Vaccine & Infect Dis Inst VAXINFECTIO, B-2020 Antwerp, Belgium
[13] Univ Antwerp, Dept Microbiol, B-2020 Antwerp, Belgium
[14] Univ Rovira & Virgili, E-43007 Tarragona, Spain
[15] Spanish Soc Family Med, Barcelona, Spain
[16] Maastricht Univ, CAPHRI, Maastricht, Netherlands
[17] Univ Tromso, Gen Practice Res Unit, Tromso, Norway