Concurrent physician-diagnosed asthma and chronic obstructive pulmonary disease: A population study of prevalence, incidence and mortality

PLoS One. 2017 Mar 16;12(3):e0173830. doi: 10.1371/journal.pone.0173830. eCollection 2017.

Abstract

Objective: We conducted a population-based cohort study to estimate trends in prevalence, incidence, and mortality of concurrent physician-diagnosed asthma and chronic obstructive pulmonary disease (COPD).

Study design and setting: Two validated health administrative case definitions were used to identify asthma and COPD among all individuals aged 35 years and older living in Ontario, Canada. Annual asthma, COPD, and concurrent asthma and COPD prevalence, incidence, and mortality, standardized for age and sex, were estimated, and compared from 2002 to 2012, using generalized linear models.

Results: Standardized prevalence of concurrent asthma and COPD increased by 10.5%, from 2.9% in 2002 to 3.2% in 2012 overall, but more prominently in women compared to men. Overall, standardized incidence decreased by16%, from 2.5 to 2.1 per 1000 individuals, but increased significantly in young adults. All-cause mortality among patients with concurrent asthma and COPD decreased by 11.2%, from 2.6% to 2.2%. Being diagnosed with both diseases was significantly associated with higher all-cause mortality compared to asthma (OR = 1.56, 95% CI: 1.50-1.58), but not compared to COPD (OR = 0.97, 0.96-0.98), except in young adults aged 35 to 49 years where people with asthma and COPD had higher mortality (OR = 1.21, 1.15-1.27).

Conclusions: In a large North American population, the burden of concurrent physician-diagnosed asthma and COPD is increasing, particularly in women and young adults.

MeSH terms

  • Adult
  • Aged
  • Asthma / complications
  • Asthma / diagnosis*
  • Asthma / epidemiology
  • Asthma / mortality
  • Humans
  • Incidence
  • Middle Aged
  • Ontario / epidemiology
  • Practice Patterns, Physicians'*
  • Prevalence
  • Pulmonary Disease, Chronic Obstructive / complications
  • Pulmonary Disease, Chronic Obstructive / diagnosis*
  • Pulmonary Disease, Chronic Obstructive / epidemiology
  • Pulmonary Disease, Chronic Obstructive / mortality

Grants and funding

This project is supported by the Canadian Respiratory Research Network (CRRN) and the Canadian Institutes of Health Research (CIHR). The CRRN is supported by grants from the CIHR - Institute of Circulatory and Respiratory Health; Canadian Lung Association (CLA)/Canadian Thoracic Society (CTS); British Columbia Lung Association; and Industry Partners Boehringer-Ingelheim Canada Ltd, AstraZeneca Canada Inc., and Novartis Canada Ltd. This study was supported by the Institute for Clinical Evaluative Sciences (ICES), which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care (MOHLTC). The opinions, results and conclusions reported in this paper are those of the authors and are independent from the funding sources. No endorsement by ICES or the Ontario MOHLTC is intended or should be inferred. Dr. Kendzerska is supported by the CRRN Fellowship Training Award. Funding for training of graduate students and new investigators within the Network was supported by the above funding Sponsors and as well by GlaxoSmithKline Inc. The funding Sponsors had no role in the study design, data collection and analysis, or preparation of the manuscript. Dr. FitzGerald is a member of the Global Initiative for Asthma (GINA) Science Committee. Dr. Lougheed has received research funding not related to this study paid directly to Queen’s University from GlaxoSmithKline, Janssen and Hoffmann LaRoche.