Racial or ethnic variation in spirometric lung function norms. Recommendations based on study of Ethiopian Jews

It is widely known that different ethnic (or racial) groups do not appear to have lung function test results which fit the same prediction formulae. Israel, with ethnic minorities from many countries, is faced with a dilemma as to what to use as a basis for normative estimates. We studied 146 Ethiopian Jewish immigrants (68 males and 78 females), all nonsmokers with no evidence of any chronic disease. The FEV1 and FVC were analyzed separately by sex and age (those less than 25 and those 25 years or more of age). Standard prediction formulae based on height overpredicted the values found by from 15 to 29 percent. Logarithmic formulae based on sitting height provided a good fit for values for children (less than 25 years). Compared to other populations the sitting height-standing height ratio was low for this population, (0.48 vs 0.52) reflecting their relatively long limbs and shorter thoracic height. Our findings suggest that as a guideline, ethnic groups with deviant standing height-sitting height ratios either use ethnic-group specific prediction formulae or derive prediction formulae using sitting height.