Criteria for COPD Diagnosis Misses Some Patients

Using a fixed ratio (FR) of forced expiratory volume in 1 second (FEV₁) to forced vital capacity (FVC) of <0.7 to diagnose airflow obstruction may classify a significant number of older adults with breathlessness as having chronic obstructive pulmonary disease (COPD), according to a study published in the International Journal of Chronic Obstructive Pulmonary Disease.

The study compared clinical characteristics of 2607 primary care patients with chronic respiratory symptoms tested using FR as the diagnostic threshold for airflow obstruction vs those diagnosed using the more statistics-based definition of FEV₁/FVC below the lower limit of normal (below the fifth percentile adjusted for age, sex, height, and ethnic group, LLN). Consensus on which is a better COPD gauge remains unresolved in the medical field.

Using FR criteria, 32.6% had airflow obstruction; 20.2% had airflow obstruction using LLN criteria. Compared with patients classified as having COPD by FR and LLN, patients diagnosed with COPD by FR alone were older with better lung function, lower symptom burden, and a higher prevalence of heart disease.

Patients diagnosed with COPD by LLN alone were more likely to have a past history of asthma compared with patients without airflow obstruction. In addition, the LLN classified several younger, very symptomatic women as having COPD but the FR did not.  

“It is well recognized that the FR criterion will not only over-diagnose airflow obstruction in the older population but also miss the diagnosis in younger females,” researchers wrote. “In the current study, the 3 highly symptomatic females who were misclassified as having no airflow obstruction using the FR potentially have a lot to gain from clinical intervention.”

—Jolynn Tumolo

For more articles like this, visit the COPD Resource Center

For articles by IH Executive, click here

For articles by First Report Managed Care, click here