Study Probes COPD Mortality Among People in Low- and Middle-Income Countries

The data largely align with outcomes in high-income countries, with male sex and people with low body weight at particular high risk of mortality.

A new report is adding to the scientific community’s understanding of how chronic obstructive pulmonary disease (COPD) affects patients in low- and middle-income countries.

COPD is an increasingly prevalent disease and the subject of no small amount of scientific study. However, as the authors of a new study note, most of the research into COPD focuses on populations of high-income countries.

“For this reason, it is especially important to understand survival and factors associated with survival in COPD patients in these countries,” they wrote Frontiers in Big Data.

The investigators used a Brazilian national health database to retrospectively track a cohort of patients who received care for COPD between 2003 and 2015. The database yielded 37,938 patients, of whom 11,452 were matched based on sex, age, and year of entry into treatment in order to assess the impact of particular therapies on survival. The mean follow-up was 37.8 months for the overall cohort and 37.7 months in the matched cohort. The average patient age was 65.2 and 64.8 years, respectively.

The data showed that, after on1e year, 97.6% (95% CI, 97.4%-97.8%) had survived. After a decade, survival was 83.1% (95% CI, 81.9%-84.3%).

A few factors appeared to increase the risk of death: being male, being over the age of 65, and being underweight. The authors said those findings largely aligned with existing data, noting that low body mass index (BMI) affects 25% to 40% of patients with COPD and is considered a poor prognostic factor.

“Malnutrition is a well-recognized risk factor for mortality among COPD patients at all stages of the disease, and BMI is one of the 4 criteria of the BODE (body mass index, airflow obstruction, dyspnea, and exercise capacity) index for mortality,” they wrote.

The authors said their data underscore the importance of nutritional care programs.

In terms of treatment regimens, the authors said some of the latest therapies for COPD are not universally available in Brazil. They noted that previous research has suggested inhaled corticosteroids (ICS) along with an ultra-long-acting beta-2-agonist (LABA) is more effective than individual components. Yet, existing data also suggest that about 70% of patients with COPD are treated with an ICS and only about half patients with a new diagnosis started with a LABA/ICS fixed-dose combination.

“Our study showed that this proportion is even higher, which may have occurred because of the narrow treatment options available in [Brazil’s health system],” the authors said.

In the new analysis, patients taking a bronchodilator in a free dose along with a fixed-dose combination of a corticosteroid and bronchodilator appeared to be the most protected against mortality compared with other regimens.

The investigators discussed a number of limitations to their research. For one, it does not include data on newer medications, patients on private insurance, or patients participating in other types of subsidized-medicine programs. They added that they incorporated data from secondary databases, which might have affected their data quality.

However, as debate continues over which therapies are best for which patients, the authors said these data pertaining to people from low- and middle-income countries are an important piece of the puzzle.


Gargano LP, Zuppo IF, do Nascimento MMG, et al. Survival analysis of COPD patients in a 13-year nationwide cohort study of the Brazilian national health system. Front Big Data. Published online February 7, 2022. doi:10.3389/fdata.2021.788268