Validation of spirometry prediction equations in western Kenya.

SETTING

Community of Eldoret, Kenya.

OBJECTIVE

To test the performance of three commonly used spirometry prediction equations in a healthy Kenyan population.

DESIGN

Cross-sectional assessment of healthy adults in Eldoret.

RESULTS

Of the 331 subjects enrolled in the study, 282 subjects aged 18-85 years (45% males, 55% females) produced high-quality spirograms. Lung function predictions were made using the Global Lung Initiative 2012 (GLI 2012) prediction equations for African Americans, the National Health and Nutrition Examination Survey III (NHANES III) prediction equations for African Americans, and the Crapo prediction equation. Bland-Altman analyses were performed to measure the agreement between observed and predicted spirometry parameters. Overall, the GLI 2012 and NHANES equations for African Americans performed similarly for forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1), significantly overestimating FVC while accurately predicting observed FEV1 values.

CONCLUSION

The study brings into question the utility of three major spirometry prediction equations in a Kenyan population. The significant overestimation of FVC by the best-performing equations despite accurate prediction of FEV1 suggests poor performance of these equations in our population.