Normal spirometry values in healthy elderly: the Rotterdam Study

Although many different reference values for spirometry are available from various studies, the elderly are usually underrepresented. Therefore, our objective was to assess reference values in a sample of healthy participants from a prospective population-based cohort study, including a large proportion of elderly. We included spirometry measurements of healthy, never smokers, from the Rotterdam Study and excluded participants with respiratory symptoms or prescriptions for respiratory medication. Age- and height-specific curves for the 5th (lower limit of normal) and the 50th (median) percentile of Forced Expiratory Volume in 1 s (FEV1), Forced Vital Capacity (FVC), and the ratio (FEV1/FVC) were calculated by quantile regression models. The group of healthy elderly study subjects consisted of 1,125 individuals, with a mean age of 68 years, ranging from 47 to 96 years of age. Sex stratified equations for the median and the lower limit of normal were calculated adjusted for age and height. In this study, we report age- and height-dependent reference limits for FEV1, FVC, and FEV1/FVC in a large population, and prediction equations for the lower limit of normal and median values for a sample containing a large proportion of healthy elderly.