Training perception of acute airflow obstruction.

Ten asthmatics selected for their tendency to experience frequent acute exacerbations were instructed in peak flow measurement. Each subject then recorded estimated peak flow (EPF) and measured peak flow (PF) at home twice daily. Data for up to 56 consecutive observations (4 weeks) per subject were analyzed. The correlation coefficient between EPF and PF following PF drops of 15% was .993 overall and was not significantly different following PF drops even greater than 25%. The absolute and proportional differences between PF and EPF were also not significantly affected by the magnitude of PF drop but decreased over time indicating improved accuracy of estimates with practice. Asthmatics can be trained to estimate accurately acute drops in airflow. Such ability has not been demonstrated in prior studies which utilized verbal symptom reports as indicators of subjective perception of airflow. Accurate perception would be a useful aid in achieving early recognition of acute exacerbations and in improving medication compliance. It is an adjunct to regular peak flow measurement, not a substitute for it.