title: Prediction Equations for Spirometry for Children from Northern India.
abstract: OBJECTIVE
  To develop prediction equations for spirometry for children from northern India using current international guidelines for standardization.
  
  
  METHODS
  Re-analysis of cross-sectional data from a single school.
  
  
  METHODS
  670 normal children (age 6-17 y; 365 boys) of northern Indian parentage.
  
  
  METHODS
  After screening for normal health, we carried out spirometry with recommended quality assurance according to current guidelines. We developed linear and nonlinear prediction equations using multiple regression analysis. We selected the final models on the basis of the highest coefficient of multiple determination (R2) and statistical validity.
  
  
  METHODS
  Spirometry parameters: FVC, FEV1, PEFR, FEF50, FEF75 and FEF25-75.
  
  
  RESULTS
  The equations for the main parameters were as follows: Boys, Ln FVC = -1.687+0.016*height +0.022*age; Ln FEV1 = -1.748+0.015*height+0.031*age. Girls, Ln FVC = -9.989 +(2.018*Ln(height)) + (0.324*Ln(age)); Ln FEV1 = -10.055 +(1.990*Ln(height))+(0.358*Ln(age)). Nonlinear regression yielded substantially greater R2 values compared to linear models except for FEF50 for girls. Height and age were found to be the significant explanatory variables for all parameters on multiple regression with weight making no significant contribution.
  
  
  CONCLUSIONS
  We developed prediction equations for spirometry for children from northern India. Nonlinear equations were superior to linear equations.
authors: Department of Pulmonary Medicine, Vallabhbhai Patel Chest Institute, and *Department of Biostatistics and Medical Informatics, University College of Medical Sciences; Delhi, India. Correspondence to: Prof SK Chhabra, Department of Pulmonary Medicine, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi 110 007, India. skchhabra@mailcity.com.
authors: Sunil K
authors: SK
authors: Chhabra
authors: Rajeev
authors: R
authors: Kumar
authors: Vikas
authors: V
authors: Mittal
mesh_terms: D000293:Adolescent; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D005540:Forced Expiratory Flow Rates / Q000502:physiology*; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D012016:Reference Values; D012044:Regression Analysis; D013147:Spirometry / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data; D014797:Vital Capacity / Q000502:physiology*