The influence of lung function information on self-reports of dyspnea by children with asthma.

Studied the influence of actual and false peak flow (PEF) information on dyspnea (breathlessness) in two experiments, each with 30 children with and 30 without asthma (7-17 years). Dyspnea, PEF, and lung function were measured before and after standardized physical exercise. Dyspnea was measured with a visual analog scale. PEF was measured with a peak flow meter and used for manipulation of dyspnea. The first experiment showed that the relationship between dyspnea and lung function was not stronger when children had knowledge of PEF values. The second experiment revealed that asthmatic children who received false feedback of 30% below the actual PEF reported significantly more dyspnea. Implications for the management of asthma are discussed.