A prospective evaluation of plain radiographic signs of chronic obstructive pulmonary disease

Plain film signs of COPD, spirometric evidence of airflow obstruction, and smoking history were correlated in a group of 182 men aged 32 to 85 years (average, 57.5 years) who presented for evaluation of possible pulmonary disability. There were 148 current or past smokers (range, 0.66 to 150 pack-years; average, 31.89 pack-years) and 34 lifetime nonsmokers. A single observer, who had no knowledge of the other parameters, prospectively evaluated posteroanterior chest radiographs for 11 signs of COPD. Airflow obstruction was defined as a reduction in FEV1/FVC% below the 95% confidence limit of normal. Obstruction was classified on the basis of the reduction in FEV1 as mild (FEV1 greater than 2.5L), moderate (FEV1 greater than 1.0 L and less than 2.5 L), or severe (FEV1 less than 1.0 L). Spirometric evidence of airflow obstruction was present in 67 patients; obstruction was mild in 26, moderate in 36, and severe in 5. We found a statistically significant association between smoking and airflow obstruction on spirometry (P less than 0.001) and an equally significant association between smoking and radiographic signs of COPD on plain chest films (P less than 0.001). Both airflow obstruction and radiologic signs of COPD were generally absent in lifetime nonsmokers. The plain film signs of COPD were only of moderate value in predicting spirometric evidence of airflow obstruction in smokers; spirometric evidence is not the gold standard for the presence of COPD, however, and the strong association between smoking and these radiologic signs may indicate that in smokers the presence of plain film signs of COPD reflects morphologic abnormality in the lungs indicative of disease.(ABSTRACT TRUNCATED AT 250 WORDS)