Prediction Equation for Spirometric Parameters in Cairo Governorate Adult Population

Abstract

ulmonary function tests are the fundamental tool to evaluate the respiratory system of an individual and of all the tests, spirometer is by far the most common one used in the diagnosis, assessment and management of patients with different lung diseases. To make an assessment or interpretation of an observed value it is compared with a reference value, defined as ‘normal’ and is derived from a representative sample of healthy subjects. Unlike most other measurements in medicine where universally applicable normal ranges are available, lung function shows wide variations even in ‘normal’ not only due to technical factors related to equipment and procedures, but also due to biological and environmental factors. These include racial, ethnic, sex, anthropometric factors, socio-economic, geographical, climatic and nutritional conditions so that prediction equations developed in one set of population may not be applicable to a different set of population. The interpretation and categorization of spirometric results depend on comparison with reference values derived from ‘‘normal’’ populations.