Challenges in Collating Spirometry Reference Data for South-Asian Children: An Observational Study.
Spirometry datasets from South-Asian children were collated from four centres in India and five within the UK. Records with transcription errors, missing values for height or spirometry, and implausible values were excluded(n = 110).



Following exclusions, cross-sectional data were available from 8,124 children (56.3% male; 5-17 years). When compared with GLI-predicted values from White Europeans, forced expired volume in 1s (FEV1) and forced vital capacity (FVC) in South-Asian children were on average 15% lower, ranging from 4-19% between centres. By contrast, proportional reductions in FEV1 and FVC within all but two datasets meant that the FEV1/FVC ratio remained independent of ethnicity. The 'GLI-Other' equation fitted data from North India reasonably well while 'GLI-Black' equations provided a better approximation for South-Asian data than the 'GLI-White' equation. However, marked discrepancies in the mean lung function z-scores between centres especially when examined according to socio-economic conditions precluded derivation of a single South-Asian GLI-adjustment.



Until improved and more robust prediction equations can be derived, we recommend the use of 'GLI-Black' equations for interpreting most South-Asian data, although 'GLI-Other' may be more appropriate for North Indian data. Prospective data collection using standardised protocols to explore potential sources of variation due to socio-economic circumstances, secular changes in growth/predictors of lung function and ethnicities within the South-Asian classification are urgently required.
Respiratory, Critical Care & Anaesthesia section (Portex Unit), UCL, Institute of Child Health, London, United Kingdom.
Sooky
S
Lum
Respiratory, Critical Care & Anaesthesia section (Portex Unit), UCL, Institute of Child Health, London, United Kingdom.
Vassiliki
V
Bountziouka
Department of Pulmonary Diseases and Department of Paediatrics-Pulmonary Diseases, Erasmus Medical Centre, Erasmus University, Rotterdam, Netherlands.
Philip
P
Quanjer
Respiratory, Critical Care & Anaesthesia section (Portex Unit), UCL, Institute of Child Health, London, United Kingdom.|Department of Paediatric Pulmonology, Rainbow Children's Hospital, Bangalore, India.
Samatha
S
Sonnappa
Clinical Epidemiology, Nutrition and Biostatistics section, UCL, Institute of Child Health, London, United Kingdom.
Angela
A
Wade
Institute for Lung Health, NIHR Leicester Respiratory Biomedical Research Unit, and Department of Infection, Immunity & Inflammation, University of Leicester, Leicester, United Kingdom.
Caroline
C
Beardsmore
Department of Pulmonary Medicine, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India.
Sunil K
SK
Chhabra
Community Medicine Department, PDU Medical College, Rajkot, Gujarat, India.
Rajesh K
RK
Chudasama
Population Health Research Institute, St George's, University of London, London, United Kingdom.
Derek G
DG
Cook
Diabetes & Nutritional Sciences Division, Kings College London, London, United Kingdom.
Seeromanie
S
Harding
Institute of Social and Preventative Medicine, University of Bern, Switzerland.
Claudia E
CE
Kuehni
Department of Physiology, Vemana Yoga Research Institute, Hyderabad, India.
K V V
KV
Prasad
Population Health Research Institute, St George's, University of London, London, United Kingdom.
Peter H
PH
Whincup
Respiratory, Critical Care & Anaesthesia section (Portex Unit), UCL, Institute of Child Health, London, United Kingdom.
Simon
S
Lee
Respiratory, Critical Care & Anaesthesia section (Portex Unit), UCL, Institute of Child Health, London, United Kingdom.
Janet
J
Stocks
D000293:Adolescent; D000465:Algorithms; D000886:Anthropometry; D044466:Asian People; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003625:Data Collection / Q000379:methods*; D003627:Data Interpretation, Statistical; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D015233:Models, Statistical; D011446:Prospective Studies; D012016:Reference Values; D013147:Spirometry / Q000379:methods*; D006113:United Kingdom