A patient's age and the number of cigarettes smoked over time can predict mortality in cases of chronic obstructive pulmonary disease, researchers say. Spirometry results were not a predictor, they reported at the European Respiratory Society's annual meeting in Vienna, Austria.
"As both age and the accumulated tobacco consumption are significant predictors of mortality, early detection of COPD is essential to provide smoking cessation interventions in the earlier stages of the disease," Dr Saher Shaker, who led the study at Gentofte Hospital in Copenhagen, Denmark, told Reuters Health by email.
Over the course of 10 years, Dr Shaker's team examined 208 patients with moderate to severe COPD. In that time, 104 patients died, and the median survival time was 10.4 years.
Statistics of COPD
On multivariate analysis, statistically significant predictors of mortality, included age (p=0.005), pack years (p=0.02), and RA-910 (relative area of emphysema below -910 Hounsfield units) as measured by computed tomography (p=0.017).
Lung function tests, including forced expiratory volume in one second (FEV1), and the diffusing capacity of the lung for carbon monoxide (DLCO), were not statistically significant predictors. That came as a surprise, Dr Shaker said.
"However," he pointed out, "spirometry is important to establish the diagnosis and assess disease severity. The degree of emphysema assessed by CT correlates closely to the pathological extent of the disease, which might explain its prognostic superiority to lung function."
(Reuters Health, Rob Goodier, September 2012)
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