Peak expiratory flow rate values of students in Bangkok.

ABSTRACT

BACKGROUND: As there are considerable variations in normal values of peak expiratory flow rate (PEFR) shown by studies from various population, a study is required to obtain normal values of PEFR in Thai children. OBJECTIVE: To determine the values of PEFR of students in Bangkok. METHODS: In a cross sectional study of PEFR measured with standard Wright peak flow meter, 501 normal students, aged 5 to 15 years, from five public schools in Bangkok were investigated. In the selection process of subjects, strict criteria of "normality" were applied and included history of medical illnesses, physical examination and nutritional status. RESULTS: The relationship between PEFR and height was approximately linear in both male and female children. Prediction equations for each sex were Male children PEFR (L/min) = [3.52 x Height (cm)] - 186.80 Female children PEFR (L/min) = [3.48 x Height (cm)] - 204.11 The PEFR values of students in this study were different from the predicted values of PEFR in those of previous reports in Thai children. These discrepancies might be explained by a variety of study population and environmental factors. CONCLUSIONS: The relationship between PEFR and height of students in Bangkok is best described by a regression equation. The prediction graphs for each sex may be used to monitor PEFR values of children with obstructive airway diseases and to compare an individual's PEFR with those of others of the same height and sex.