COPD Mortality Rate Drops in Some Countries, While Total Mortality Rises, Study Finds

An international study examining trends in chronic obstructive pulmonary disease (COPD) mortality over more than 2 decades showed that COPD mortality rates declined in most countries but remained stable among US women and increased in several European countries, with total mortality additionally increasing or remaining stable in most countries.

The study, published last week in the European Respiratory Journal, analyzed international trends in COPD mortality from 1995-2017, based on data from the World Health Organization (WHO). COPD, which has been the third-leading cause of death worldwide since 2016, exhibited declines in global mortality rates since the 1990s, but as the study authors note, little is known about observed trends in COPD mortality in Latin America, as well as Oceania and Europe.

Lead study author Joannie Lortet-Tieulent, MD, research fellow at the WHO International Agency for Research on Cancer, highlighted that while WHO data presents COPD as a burden of high importance, existing COPD mortality data was based on outdated statistics from a select number of high-income countries in Europe, Australia, Japan, and the United States. “There is a need to publish up-to-date estimates and to include mortality data from more varied regions of the world in international comparisons,” said Lortet-Tieulent.

Researchers sought to address this lack of global representation by analyzing 3.36 million COPD deaths derived from the WHO mortality database based on age (50-84), sex, and year. The data set included 24 countries worldwide, each of which had a population of at least 2 million people and available high-quality mortality data from the previous decade:

• The study included 6 countries in Latin America and the Caribbean, 2 each in North America, Asia, and Oceania, and 12 European countries
• COPD mortality rates calculated through setting the number of COPD deaths per year against the population of each country in the same year
• Data standardized using a reference population to ensure accuracy of comparisons between populations over time

Based on data taken from 2 study periods conducted from 2000 to 2015, the combined mortality rate for all studied countries fell by 12% (2000: 68 deaths per 100,000 people per year; 2015: 60 deaths per 100,000 people per year), with total mortality increasing by 12% (2000: 180,950 estimated COPD deaths; 2015: 203,090 estimated COPD deaths).

Lortet-Tieulent noted that the findings may be attributed to increased life expectancy worldwide, in which people dying from COPD is a result of aging populations. “The data suggests that the proportion of COPD patients who are dying early due to the disease is falling overall, and that is very encouraging. It means that people may be less exposed to COPD risk factors now and that COPD is being managed more effectively,” said Lortet-Tieulent.

Among global populations exhibiting a heightened COPD mortality rate by sex, rates were highest in Hungary and Kyrgyzstan for men, and highest for women in the United States and Hungary. The analysis further showed that while the general trend of worldwide COPD death rates shows a decline, death rates for women remained constant in North America and increased in the European countries Czechia (+4.2%), Hungary (+4.8%), and Austria (+2%).

"In the countries where women have been smoking as much and for as long as men, such as the USA, New Zealand and the UK, the female COPD death rate became very similar to that of men over time. Raising awareness of COPD in females could enable earlier diagnosis, thereby improving management and lowering the risk of death,” said Lortet-Tieulent.

The study authors noted that the study data likely underestimated the true mortality burden of COPD, that more high-quality data from low-income countries is warranted to achieve accurate estimates of global COPD deaths.

Reference

Lortet-Tieulent J, Soerjomataram I, López-Campos JL, et al. International trends in chronic obstructive pulmonary disease mortality, 1995—2017. Eur Respir J. [published online November 20, 2019]. doi: 10.1183/13993003.01791-2019.