Objective: To estimate the lung function prediction equation and to calculate appropriate normal reference values for the Pakistani adults living in Karachi.
Methods: Predicted equations for normal lung functions were derived from 504 healthy non-smoking subjects including 321 males and 183 females aged 15-65 years. The subjects underwent measurement of spirometric flow and volume. The following variables were measured: forced vital capacity (FVC), forced expiratory volume in one second (FEV1), maximal mid expiratory flow (MMEF) and peak expiratory flow (PEF). Regression analysis using height and age as independent variables were applied to provide predicted values for both sexes.
Results: There was negative correlation between each pulmonary function and age. All parameters correlate positively with height. The largest negative correlation was found for FEV1 and FVC in males, while the largest positive correlation was observed for FVC in females.
Conclusion: In this study set of PFT reference values and prediction equations for both sexes have been derived using healthy, non-smoking urban Pakistani population which was different from several other prediction equations.