Kjell Torén1, Martin Andersson2, Anna-Carin Olin3, Paul D Blanc4, Bengt Järvholm2. 1. Section of Occupational and Environmental Medicine, Sahlgrenska Academy, University of Gothenburg, Box 414, SE-405 30, Gothenburg, Sweden; Department of Occupational and Environmental Medicine, Sahlgrenska University Hospital, Box 414, SE-405 30, Gothenburg, Sweden. Electronic address: Kjell.Toren@amm.gu.se. 2. Department of Occupational and Environmental Medicine, Institute of Clinical Medicine and Public Health, University of Umeå, SE-901 87, Umeå, Sweden. 3. Section of Occupational and Environmental Medicine, Sahlgrenska Academy, University of Gothenburg, Box 414, SE-405 30, Gothenburg, Sweden; Department of Occupational and Environmental Medicine, Sahlgrenska University Hospital, Box 414, SE-405 30, Gothenburg, Sweden. 4. Division of Occupational and Environmental Medicine, Department of Medicine, University of California, PO 0924, San Francisco, CA, USA.
Abstract
BACKGROUND: There is controversy as to whether airflow limitation should be defined as forced expiratory volume in 1 s (FEV1)/vital capacity (VC) < 0.7 or as FEV1/VC< the lower limit of normal (LLN). The aim was to examine whether different definitions of airflow limitation differ in predicting mortality. METHODS: Longitudinal prospective study of a national cohort of Swedish workers (199,408 men; 7988 women), aged 20-64 years with spirometry without bronchodilation at baseline followed from 1979 until death, or censorship at 2010. Airflow limitation (AL) by Global Obstructive Lung Disease criteria, ALGOLD, was defined as FEV1/VC < 0.7; ALLLN as FEV1/VC < LLN. All all-cause, COPD and cardiovascular disease mortality was analyzed among men and women in relation to ALGOLD and ALLLN, adjusted for age and smoking. RESULTS: Among men, all-cause mortality risks were similar by airflow limitation criteria: ALGOLD RR = 1.32, 95% CI 1.26-1.38; ALLLN, RR = 1.37, 95% CI 1.31-1.44. The risk estimates were also similar by airflow limitation definition for cardiovascular mortality and for COPD mortality. Among women, all-cause mortality was also similar by airflow limitation criteria, but significantly higher as compared to men: ALGOLD RR = 2.10, 95% CI 1.66-2.66; ALLLN, RR = 2.09, 95% CI 1.66-2.62. Also cardiovascular and COPD mortality by airflow limitation criteria was significantly higher among women as compared to men. CONCLUSIONS: Defined either as FEV1/VC < 0.7 or as FEV1/VC < LLN, airflow limitation predicted excess mortality risk of similar magnitude. Mortality in relation to airflow limitation was higher among women compared to men.
BACKGROUND: There is controversy as to whether airflow limitation should be defined as forced expiratory volume in 1 s (FEV1)/vital capacity (VC) < 0.7 or as FEV1/VC< the lower limit of normal (LLN). The aim was to examine whether different definitions of airflow limitation differ in predicting mortality. METHODS: Longitudinal prospective study of a national cohort of Swedish workers (199,408 men; 7988 women), aged 20-64 years with spirometry without bronchodilation at baseline followed from 1979 until death, or censorship at 2010. Airflow limitation (AL) by Global Obstructive Lung Disease criteria, ALGOLD, was defined as FEV1/VC < 0.7; ALLLN as FEV1/VC < LLN. All all-cause, COPD and cardiovascular disease mortality was analyzed among men and women in relation to ALGOLD and ALLLN, adjusted for age and smoking. RESULTS: Among men, all-cause mortality risks were similar by airflow limitation criteria: ALGOLD RR = 1.32, 95% CI 1.26-1.38; ALLLN, RR = 1.37, 95% CI 1.31-1.44. The risk estimates were also similar by airflow limitation definition for cardiovascular mortality and for COPD mortality. Among women, all-cause mortality was also similar by airflow limitation criteria, but significantly higher as compared to men: ALGOLD RR = 2.10, 95% CI 1.66-2.66; ALLLN, RR = 2.09, 95% CI 1.66-2.62. Also cardiovascular and COPD mortality by airflow limitation criteria was significantly higher among women as compared to men. CONCLUSIONS: Defined either as FEV1/VC < 0.7 or as FEV1/VC < LLN, airflow limitation predicted excess mortality risk of similar magnitude. Mortality in relation to airflow limitation was higher among women compared to men.
Authors: Kjell Toren; Linus Schiöler; Anne Lindberg; Anders Andersson; Annelie F Behndig; Göran Bergström; Anders Blomberg; Kenneth Caidahl; Jan Engvall; Maria Eriksson; Viktor Hamrefors; Christer Janson; David Kylhammar; Eva Lindberg; Anders Lindén; Andrei Malinovschi; Hans Lennart Persson; Martin Sandelin; Jonas Eriksson Ström; Hanan A Tanash; Jenny Vikgren; Carl Johan Östgren; Per Wollmer; C Magnus Sköld Journal: BMJ Open Respir Res Date: 2020-08