A simple health assessment could reduce the global burden of chronic obstructive pulmonary disease (COPD), which is the world’s third leading cause of morbidity with more than three million deaths a year.
The large-scale international study led by UCL researchers and published in JAMA, found that people at high-risk of COPD could be identified in under 10 minutes using either a questionnaire on its own or a questionnaire combined with a Peak Expiratory Flow (PEF) assessment, a low-cost device that tests how fast a person can exhale.
COPD is one of the world’s major public health issues. It includes serious lung conditions, such as emphysema and chronic bronchitis, and is the greatest burden is in low- and middle-income countries (LMIC), which account for around 90% of COPD related deaths. Globally, COPD has also been a major risk factor associated with Covid-19 outcomes.
In high-income countries, COPD is typically caused by smoking tobacco and is diagnosed using a spirometer, where an individual blows into a device that measures how much air a person can breathe out in one forced breath. Diagnosis is straightforward and symptoms can be effectively treated.
However, in LMICs the primary cause of COPD is more varied and includes household air pollution in the form of biomass smoke for cooking and heating; other causes include impaired lung growth, chronic asthma and post-tuberculosis lung damage. And diagnosis in LMICs is hindered as spirometry – the ‘gold-standard’ for diagnosing COPD – is often not available. There is a shortage of clinicians needed to perform and interpret the tests, therefore rolling these out is costly. As a result, COPD is commonly undiagnosed in LMICs.
Assessing the burden of COPD
In the study, researchers assessed three COPD screening tools on populations in three distinct settings: semiurban Bhaktapur, Nepal, urban Lima, Peru and rural Nakaseke, Uganda.
Two of the screening tools (COLA 6 and CAPTURE) comprised a questionnaire and PEF. The other screening tool, LFQ, solely involved a questionnaire. All three screening tools were tested in all three settings.
To establish diagnostic accuracy of the tools, all participants were also given a spirometry test. In total 10,709 male and female adults aged 40 years or older from the three communities took part. Participants were recruited irrespective of symptoms and/or a prior diagnosis of COPD, but needed to be able to perform spirometry.
It found that prevalence of COPD varied by site, from 3% in Lima (Peru) to 7% in Nakaseke (Uganda) and 18% in Bhaktapur (Nepal).
Of COPD cases, 49% were clinically significant as defined by symptoms and or exacerbation burden, and 16% had severe or very-severe disease measured on spirometry. 95% of cases were previously undiagnosed.
The screening instruments performed similarly within each population setting and were feasible to deliver using trained research staff, taking an average of 7-8 minutes.
Simple screening tools to identify people affected by COPD
Principal Investigator Professor John Hurst (UCL Division of Medicine) said: “Our findings support the accuracy and feasibility of using simple screening tools to identify people affected by COPD living in diverse low- and middle-income settings.
“It is alarming that a high percentage of screen-identified COPD cases were clinically important, had severe or very severe changes in lung function, and that most were unaware of their diagnosis despite the high prevalence of symptoms and lower quality of life.
“In addition, only a minority of people had a history of smoking, further highlighting the poor conditions, exacerbated by biomass smoke, that people in low- and middle-income countries are living.”
Researchers say further studies will be required to assess if COPD screening can be implemented in routine LMIC healthcare settings; if screening for COPD is of benefit to those testing positive, and it is cost-effective, for a given population, to implement COPD screening in LMIC settings.