The FEV1/FEV6 ratio is a good substitute for the FEV1/FVC ration in the elderly

Abstract

<h4>Aims</h4>To determine the agreement between the FEV1/FEV6 ratio and the FEV1/FVC ratio in an elderly population.<h4>Method</h4>The study sample consisted of 3874 participants in a cross-sectional population survey in Tromsö, Norway, aged 60 years or more, in whom acceptable spirometry had been obtained. Mean differences between the FEV1/FEV6 ratio (%) and the FEV1/FVC ratio (%) were calculated according to age, sex, smoking habit, and the degree of airflow limitation. ROC-curve analysis and Kappa-statistics were used to estimate the utility of the FEV1/FEV6 ratio in predicting an FEV1/FVC ratio < 70%.<h4>Results</h4>The mean difference between FEV1/FEV6% and FEV1/FVC% was 2.7% in both men and women. The difference between the two measures increased somewhat with increasing age, and was more pronounced with smoking and decreasing FEV1/FVC ratio. The value for the FEV1/FEV6 ratio which best predicted an FEV1/FVC ratio of 70%, was 73%, and a very good agreement was found between these two cut-off values (kappa = 0.86).<h4>Conclusion</h4>The FEV1/FEV6 ratio appears to be a good substitute for the FEV1/FVC ratio in an elderly population.