ASSESSMENT OF THE SEVERITY OF ASTHMA IN A FAMILY-PRACTICE

The objective of this study was to evaluate clinical history and self- perception of severity as predictors of asthma severity. A short-term longitudinal study was conducted in a family: practice in Melbourne, A ustralia, utilizing peak flow monitoring, medication diary, and self-a dministered asthma severity questionnaire. Seventy-two asthmatic subje cts with a positive bronchodilator or exercise test, aged between 6 an d 79 years, were studied. Symptom and treatment items were correlated with peak flow variability and minimal peak expiratory flow rate (PEFR ). An asthma severity scale was generated using the partial credit ver sion of Item Response Theory and the participants' severity scores wer e validated against lung function tests and medication usage. Quantita tive modeling procedures were used to investigate the interrelationshi ps of factors associated with peak flow variability. Severity scores d emonstrated significant relationships with peak flow variability (part ial r=0.34) and treatment items. Self-perceived severity of asthma in the preceding 2 weeks showed significant association with peak flow va riability (partial rho=0.46) and minimal PEFR (rho=-0.41). The severit y module of the Monash Respiratory Questionnaire is a valid and reliab le instrument. The most important symptoms appear to be the frequency of use of bronchodilator and Frequency of nocturnal attacks. A careful ly structured clinical history in conjunction with the peak flow crite ria of variability and minimal peak flow rate would be appropriate in the evaluation of asthma severity. Patients' self-perception of the se verity of their asthma needs further evaluation.