Quality of life associated with breathlessness in the multinational Burden of Obstructive Lung Disease (BOLD) study: A cross-sectional analysis
Alexander Müller, Emiel F.�M. Wouters, Peter Burney, James E. Potts, João Lourenço Cardoso, Mohammed Al Ghobain, Michael Studnicka, Daniel Obaseki, Asma Elsony, Kevin Mortimer, David M. Mannino, Rain Jögi, Rana Ahmed, Asaad Ahmed Nafees, Maria Fatima Rodrigues, Cristina Bárbara, Rune Nielsen, Þórarinn Gíslason, Hamid Hacene Cherkaski, Karima El Rhazi, Christer Janson, P A Mahesh, Sanjay Juvekar, Hermínia Brites Dias, Frits M.E. Franssen, Dhiraj Agarwal, Sylvia Hartl, Terence Seemungal, Stefanni Nonna Paraguas, Imed Harrabi, Meriam Denguezli, Abdul Rashid, Gregory E. Erhabor, M. El Biaze, Parvaiz A Koul, Daisy J.A. Janssen, André F.S. Amaral, on behalf of the BOLD Collaborative Research Group
Abstract
Introduction Evidence of an association between breathlessness and quality of life from population-based studies is limited. We aimed to investigate the association of both physical and mental quality of life with breathlessness across several low-, middle- and high-income countries.Methods We analysed data from 19 714 adults (31 sites, 25 countries) from the Burden of Obstructive Lung Disease (BOLD) study. We measured both mental and physical quality of life components using the SF-12 questionnaire, and defined breathlessness as grade ≥2 on the modified Medical Research Council scale. We used multivariable linear regression to assess the association of each quality-of-life component with breathlessness. We pooled site-specific estimates using random-effects meta-analysis.Results Both physical and mental component scores were lower in participants with breathlessness compared to those without. This association was stronger for the physical component (coefficient = −7.59; 95%CI −8.60, −6.58; I2 = 78.5%) than for the mental component (coefficient = −3.50; 95%CI −4.36, −2.63; I2 = 71.4%). The association between physical component and breathlessness was stronger in high-income countries (coefficient = −8.82; 95%CI −10.15, −7.50). Heterogeneity across sites was partly explained by sex and tobacco smoking.Conclusion Quality of life is worse in people with breathlessness, but this association varies widely across the world.