Peak expiratory flow rates in the elderly.

While there has been increasing interest in using peak flow meters in medical practice, reference values for white adults aged over 65 years are not available. Peak expiratory flow rate was studied in ambulatory adults aged 65 years and above. Healthy nonsmoking subjects were selected by stringent criteria. Multiple linear regression was used to determine equations predicting healthy peak expiratory flow rates from age and height for each sex. The results are compared with published normal values for younger adults, and the efficacy of using peak flow rates is discussed.