Spirometry reference equations for an adult Middle Eastern population

<b>Background</b>: Spirometric reference values are crucial in screening, diagnosis and monitoring the therapeutic course of respiratory diseases. These values from a representative population are key to making a precise interpretation of respiratory diseases. The objective of this study is to determine the spirometric reference values of a healthy Jordanian population. <b>Method</b>: Participants were recruited from Al-Zaytoonah University of Jordan and from several pharmacies, polyclinics and hospitals in different cities in Jordan. To formulate Jordanian-specific spirometric reference values, generalised additive models for location scale and shape (GAMLSS) were used. <b>Results</b>: Spirometric reference values were derived from 1,949 healthy nonsmoking adults (1,061 females) and validated in 300 healthy nonsmoking subjects (150 females). <b>Conclusion</b>: Spirometric reference values were developed for a Middle Eastern adult population.