PRECISION AND ACCURACY OF SELF-MEASURED PEAK EXPIRATORY FLOW-RATES INCHRONIC OBSTRUCTIVE PULMONARY-DISEASE

Background. The precision and accuracy of self-measured peak expirator y flow rates (PEFR) have not been determined for patients with chronic obstructive pulmonary disease (COPD). Methods. Twenty-eight male vete rans recorded their PEFR twice daily, before and after bronchodilators , for 6 months. Spirometry was also done in the pulmonary function lab oratory up to 11 times per patient during the observation period. A 4- week ''baseline'' was identified for each patient. Baseline coefficien ts of variation (CV) were calculated for the morning (AM) and evening (PM) PEFR, before (PRE) and after (POST) bronchodilators. Results. The baseline CVs for AMPRE, AMPOST, PMPRE and PMPOST were 14.9 +/- 6.9%, 12.6 +/- 5.6%, 14.9 +/- 4.8%, and 11.2 +/- 6.0%, respectively. There w ere strong correlations between self-measured PEFR and values obtained in the pulmonary function laboratory on the same day. Conclusions. Se lf-measured PEFRs are reasonably precise and accurate in patients with COPD.