All-age relationship between arm span and height in different ethnic groups.

The objective of the present study was to establish multiethnic, all-age prediction equations for estimating stature from arm span in males and females. The arm span/height ratio (ASHR) from 13 947 subjects (40.9% females), aged 5-99 years, from nine centres (in China, Europe, Ghana, India and Iran) was used to predict ASHR as a function of age using the lambda, mu and sigma method. Z-scores for forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC in 1503 patients were calculated using measured height and height calculated from arm span and age. ASHR varied nonlinearly with age, was higher in males than in females and differed significantly between the nine sites. The data clustered into four groups: Asia, Europe, Ghana and Iran. Average predicted FEV1, FVC and FEV1/FVC using measured or predicted height did not differ, with standard deviations of 4.6% for FEV1, 5.0% for FVC and 0.3% for FEV1/FVC. The percentages of disparate findings for a low FEV1, FVC and FEV1/FVC in patients, calculated using measured or predicted height, were 4.2%, 3.2% and 0.4%, respectively; for a restrictive pattern, there were 1.0% disparate findings. Group- and sex-specific equations for estimating height from arm span and age to derive predicted values for spirometry are clinically useful.