Global deaths, prevalence and disability for chronic obstructive pulmonary disease and asthma

A recent paper from the Global Burden of Disease (GBD) Chronic Respiratory Disease Collaborators examined the burden of ill-health caused by chronic obstructive pulmonary disease (COPD) and asthma. The paper was published in the journal The Lancet Respiratory Medicine.

COPD and asthma are common diseases with a heterogeneous distribution worldwide. In the paper, we presented findings for COPD and asthma from the Global Burden of Diseases, Injuries, and Risk Factors (GBD) 2015 study. The GBD study provides annual updates on estimates of deaths, prevalence, and disability for over 300 diseases and injuries, for 188 countries from 1990 to the most recent year.

We found that in 2015, 3.2 million people died from COPD worldwide, an increase of 11·6% compared with 1990. There was a decrease in age-standardised death rate of 41·9% but this was counteracted by population growth and ageing of the global population. From 1990 to 2015, the prevalence of COPD increased by 44%, whereas age-standardised prevalence decreased by 14·7%.

In 2015, 0·4 million people died from asthma globally, a decrease of 26·7% from 1990. The age-standardised death rate decreased by 58·8% (39·0 to 69·0). The prevalence of asthma increased by 12·6% whereas the age-standardised prevalence decreased by 17·7%.

Smoking and ambient particulate matter were the main risk factors for COPD followed by household air pollution, occupational particulates, ozone, and second-hand smoke. Together, these risks explained 73% of disability due to COPD. Smoking and occupational asthma precipitants were the only risks quantified for asthma in GBD, accounting for 16.5% (disability due to asthma.

In conclusion, asthma was the commonest chronic respiratory disease worldwide in 2015, with twice the number of cases of COPD. Deaths from COPD were eight times more common than deaths from asthma.

We also concluded that although there are laudable international collaborative efforts to make surveys of asthma and COPD more comparable, no consensus exists on case definitions and how to measure disease severity for population health measurements like GBD. Comparisons between countries and over time are important, as much of the chronic respiratory burden is either preventable or treatable with affordable interventions.