Establishing the normative values of spirometry in children of 5- 18 years age range living in and around Solan district of Himachal Pradesh, India

ABSTRACT

Introduction: Pulmonary Function Tests (PFTs), especially spirometry is an established mode of assessing chronic lung diseases especially Asthma. Spirometric reference values are essential in assessing pulmonary function. Normative values of these tests differ from population to population and with difference in methods and apparatus used. The normal standards for pulmonary function measurements among the hilly areas of Himachal Pradesh is not reported yet. Aim: To measure the normative values of spirometry (FEV1, FVC, FEV1/FVC, PEFR) in children of 5- 18 years age range living in and around Solan district of Himachal Pradesh, India. Material and Methods: This cross-sectional study was carried out at M.M Medical College and Hospital, Kumarhatti, Solan, HP, India and comprised school-going children and nearby community aged 5-18 years. After noting their gender, age, height and weight, the pulmonary function test measures, Forced vital capacity (FVC), Forced expiratory volume in 1 second (FEV1), FEV1/FVC%, FEF 25-75% and peak expiratory flow rate were taken. Simple and multiple regression models were used for the prediction of pulmonary function test values. SPSS 20 was used for statistical analysis Results: Of the 200 participants, 110(55%) were boys and 90 (45%) were girls. The mean age was 12.47±3.27 years. The means height, weight, forced expiratory volume in 1 second, force vital capacity, peak expiratory flow rate FEV1/FVC% and FEF 25-75% were 147.39±16.07cm, 41.30±12.38kg, 2.54±0.70, 2.90±0.8, 5.42±1.30, 87.41±3.85% and 2.90±0.84 respectively. All the three variables - Age, Height and Weight-had significant linear relationship and positive correlation with the pulmonary function test values (p0.7). Among these three variables maximum correlation was found with height (r=>0.8). Conclusion: Age, height and weight had statistically significant and positive correlation with the PFT values, both for boys and girls. Height was found to be most strongly and positively correlated with the PFT values. Overall significant difference was seen in FEV1/FVC and FEF 25-75 among boys and girls except FEV1, FVC and PEFR of the same age group. The fitted regression equations would help to predict the PFT values for the Indian children living in hilly areas at given age, height and weight. This study should be seen as a pilot study and will require data from a large population to establish normal values for our population.