High COPD Prevalence in Low- and Middle-Income Countries with Trishul Siddharthan, MD

With chronic obstructive pulmonary disease (COPD) being cited as the third leading cause of mortality globally, the data surrounding the condition has naturally continued to broaden.

Over the past 30 years, a myriad of drug trials and epidemiologic studies have been conducted to detail the complications of COPD, which caused an estimated 3.23 million deaths in 2019.

Despite this, the causes of morbidity and mortality from the disease can vary depending on location. In high-income countries, COPD is predominantly typically linked to cigarette exposure, though some studies have also associated the disease with tobacco smoke and poor sleep habits.

However, people in low- and middle-income countries are often predisposed to a multitude of environmental factors that are not often considered outside of high-income settings.

In an interview with HCPLive, Trishul Siddharthan, MD, Division of Pulmonary and Critical Care at the Miller School of Medicine, University of Miami, spoke of environmental exposures associated with low- and middle-income countries as well as the lack of diagnostic resources for COPD in these settings.

“When we have to think about exposures we traditionally think about cigarette exposures, but exposure occurs over the course of the lifetime,” he said. “There's really robust data supporting a range of exposures across the lifetime that are permanent to low- and middle-income settings.”

Among these exposures are intrauterine micronutrient deficiencies, uncontrolled asthma, and exposure to biomass and environmental pollutants associated with decreased lung function.

Spirometry, a common pulmonary test, is used to detect COPD in most high-income settings. However, the device can cost thousands of dollars, and while the procedure is not complicated it does require proper training.

“And so that is largely unavailable in low- and middle-income countries settings,” Siddharthan said. “This disease is highly prevalent in certain regions of the world and is largely undiagnosed, and as a result largely untreated.”

To aid in this struggle to properly treat patients with COPD, Siddharthan and colleagues utilized 3 COPD screening tools in across 3 low- and middle-income settings including semi-urban Bhaktapur, Nepal, urban Lima, Peru, and rural Nakaseke, Uganda.

“We needed a questionnaire that was relevant to the prevalence of disease at these sites, a questionnaire that was relevant to the exposures and risk factors at the sides, as well as a questionnaire that was easily easy to administer,” he said.

The 3 featured screening tools included the COPD Assessment in Primary Care to Identify Undiagnosed Respiratory Disease and Exacerbation Risk (CAPTURE), the COPD in LMICs Assessment questionnaire (COLA-6), and the Lung Function Questionnaire (LFQ).

“We wanted to find an instrument that was able to detect disease and more importantly symptomatic disease, because not all individuals with COPD or inhalers are on therapy,” Siddharthan said. “So, an instrument that will identify symptomatic disease but doesn't necessarily result in a lot of referrals for spirometry, which have downstream cost implications to systems.”

In the United States, the CAPTURE questionnaire is currently being studied for implementation in primary care settings with peak expiratory flow. With the data gathered from Siddharthan’s recent study, he is hopeful the tools will be used in a similar capacity across low- and middle-income countries.