Prediction Equations for Pulmonary Function Parameters in Central Indian Adult Population

摘要

Introduction: The prediction equations for spirometry currently used may have lost significance as they are several decades old. Also the lung health of the population has changed over the years. Moreover prediction equations for Central Indians have never been proposed. Aims: To develop prediction equations for pulmonary function parameters in Central Indian adult population and to compare them with equations currently used for Indian population. Materials and Methods: Spirometry was performed using Helios 401 machine on 445 healthy male & female subjects aged between 18 to 60 years residing in Central India using the current guidelines as recommended by ATS. Prediction equations for males & females were developed separately for FVC, FEV1, PEFR, FEF 25-75 %, FEF 0.2-1.2 litres, FEF 25%, FEF50%, FEF75% and MVV. Final models were selected considering simplicity and ease of clinical application, highest predictive capability (R2), highest F value, lowest AIC value and satisfaction of assumptions of regression analysis. Age related decline and height related increase for all the pulmonary function parameters was observed. These equations were also compared for agreement with currently used Recorders equations for Indians using Bland Altman method. Conclusion: All the observed values of pulmonary function parameters were less in central Indians as compared to the reference values suggesting either an ethnically lower values or a decline in the lung health of the population. We propose that the prediction equations for pulmonary function parameters developed in this study must be used as reference for Central Indians.