Umeå University, department of Community science and rehabilitation, Umeå, Sweden
Lycksele Hospital, Lycksele, Västerbotten, Sweden
Department of Surgery and Perioperative Sciences, Umeå University Hospital, Umeå, Västerbotten, Sweden
Dept of respiratory medicine, Umeå, Sweden
Umeå University Hospital, Umeå, Sweden
Umeå University, Epidemiology and Public Health, Umeå, Västerbotten, Sweden