FEV₆ as screening tool in spirometric diagnosis of obstructive airway disease

Context: The use of spirometry is currently limited to the diagnosis of obstructive airway disease for tertiary centers mainly because of the unmet need for technical expertise and funding. Use in primary care asks for a simpler and cost-effective screening tool for obstructive airway disease. Aim: To estimate the efficacy of FEV 6 against the current standard of FVC in the spirometric diagnosis of obstructive airway disease. Setting and Design: The Pulmonary Function Laboratory of a tertiary care hospital in Coastal South India. It was a descriptive study. Materials and Methods: We analyzed 150 serial patients on ATS standardized spirometers. The patients were classified into normal subjects and those with airway obstruction, further categorized as mild, moderate and severe and those with mixed defect. Those with obstruction were also classified as having reversible and irreversible defects. Statistical Analysis: Data was analyzed using SPSS Software (v.11.5), statistical test ANOVA and Pearson correlation was done and P less than 0.05 considered statistically significant. Results: FVC and FEV 6 showed a linear correlation in all subjects. The difference in means was statistically significant in all subjects. The sensitivity and specificity of FEV 1 /FEV 6 in comparison to FEV 1 /FVC were both found to be 100%. Conclusion: FEV 6 is an excellent screening tool in the diagnosis of airway obstruction but, there is a necessity for further research to confirm our findings. There is also a need for reference values in an Indian setting to find out the efficiency of this new parameter. Our sample size is relatively small and comprises of a very high proportion (70%) of subjects with airway obstruction and so our results may not be applicable for use in general population