Tools for COPD Diagnosis Evaluated in Two Studies
(HealthDay News) — Two studies published in the January/February issue of the Annals of Family Medicine evaluate the tools available for diagnosis of chronic obstructive pulmonary disease (COPD).
In the first study, Wouter van Dijk, MD, PhD, from Radboud University in Nijmegen, Netherlands, and colleagues compared the clinical relevance of two criteria (the fixed ratio and the lower limit of normal) for defining a low ratio of forced expiratory volume in one second (FEV1) to forced vital capacity. Data were analyzed for 4,882 patients aged 40 years and older. The researchers found that the prevalence of airflow limitation was 17 and 11% by fixed ratio and lower limit of normal, respectively. The strongest increases in odds of adverse outcomes were seen for patients with airflow limitation based on both fixed ratio and lower limit of normal and with low FEV1.
In the second study, Verónica Casado, MD, PhD, from the Parquesol Teaching Health Center in Valladolid, Spain, and colleagues conducted a cross-sectional study involving 233 adults aged 40–75 years to examine laryngeal height, lung function, and diagnostic questionnaires as diagnostic tools for COPD. The researchers observed a positive likelihood ratio of 5.21 for laryngeal height and a negative likelihood ratio of 0.10 for the Lung Function Questionnaire. The positive and negative likelihood ratios were 29.06 and 0.26, respectively, for combining the maximum laryngeal height of ≥4cm with Lung Function Questionnaire findings of ≤18.
"Combining Lung Function Questionnaire results and laryngeal height can help confirm or dismiss COPD," Casado and colleagues write.
The van Dijk study was partially funded by pharmaceutical companies.