Carbon monoxide diffusion capacity (DLCO) and arterial oxygen partial pressure (PaCO2) and age were significantly and independently associated with mortality in COPD patients, according to UK researchers.

Investigators reviewed data on 604 COPD patients who underwent lung function testing, including arterial blood gas analysis; participants had a mean 37% of predicted FEV1. Over a mean follow-up period of 80 months, 229 patients (37.9%) died. Median survival for the patients was 91.9 months.

In multivariate regression analysis, DLCO was identified as an independent predictor of survival in the patients. Younger age and increased PaCO2 were also significant predictors of survival in patients.

“An argument can therefore be made for performing measures of gas transfer in routine practice for patients with COPD to provide them with the best prognostic information, and future classifications of COPD should include DLCO and not rely merely on the severity of airflow obstruction,” the authors wrote.