COPD misclassification common in older adults

Among older adults, COPD misclassification is high and is associated with higher respiratory symptom burden, health care utilization and lower physical performance, compared with the general population, researchers reported.

“COPD misclassification may result in missed opportunities to provide disease-specific therapy that could lead to a reduction in disease burden and improve the long-term health of patients,” M.A. Malik Farooqi, MD, from the department of medicine at the Firestone Institute for Respiratory Health at McMaster University in Hamilton, Ontario, Canada, told Healio. “We aimed to assess the prevalence and health care burden of COPD misclassification in a general population of Canadian older adults.”

The longitudinal, cross-sectional study, published in BMJ Open Respiratory Research, included 21,242 Canadian participants with high-quality spirometry (mean age, 64 years; 42% men). Researchers evaluated the prevalence of self-reported physician-diagnosed COPD and compliance with spirometry airflow obstruction. Researchers then assessed associations between confirmed COPD, underdiagnosis and overdiagnosis with self-reported respiratory symptoms, health care utilization and physical performance.

Overall, 5% of participants reported physician-diagnosed COPD. Only 1% of participants had confirmed COPD supported by spirometry airflow obstruction.

Researchers reported inconsistencies among self-reported COPD and spirometry findings in 8% of participants; 4% were underdiagnosed and 4% were overdiagnosed. Participants with confirmed, under- or overdiagnosed COPD had higher risk for respiratory symptoms (adjusted OR = 2.1; 95% CI, 1.6-2.7; aOR = 1.8; 95% CI, 1.6-2.1; aOR = 1.6; 95% CI, 1.4-1.9, respectively) and health care utilization (beta = 0.8; 95% CI, 0.2-2.6; beta = 0.9; 95% CI, 0.5-1.5; beta = 1.6; 95% CI, 0.7-4, respectively) compared with participants with normal spirometry and no self-reported COPD.

In addition, participants with COPD that was confirmed (aOR = 1.7; 95% CI, 1.3-2.4) or overdiagnosed (aOR = 1.7; 95% CI, 1.4-2) had higher risk for mood disorders.

Among participants with confirmed COPD, underdiagnosed COPD and overdiagnosed COPD, researchers also reported lower physical performance for the timed-up-and-go test (0.7 s, 0.1 s and 0.4 s, respectively), handgrip strength (–0.9 kg, –0.7 kg and –0.6 kg, respectively) and 4 m walk (0.26 s, 0.01 s and 0.17 s, respectively).

“COPD misclassification is common. Misclassified patients have a high burden of respiratory symptoms, have increased health care utilization and have lower physical performance compared to healthy controls,” Farooqi told Healio.

According to Farooqi, moving forward, prospective data are required to further evaluate the long-term impact of COPD misclassification.

“The burden of COPD overdiagnosis and underutilization of spirometry remains high in the general population, despite efforts to educate care providers on the importance of airflow obstruction on spirometry in classifying patients as COPD,” Farooqi said.

For more information:

M. A. Malik Farooqi, MD, can be reached at malik.farooqi@medportal.ca.