0517. Patient symptoms better than peak flows for asthma exacerbation risk

Some years ago the American NIH-based asthma working group developed asthma guidelines that included assessment, monitoring and treatment goals. Asthma symptoms and objective peak flow measurements are both important in monitoring, whether used by patients or healthcare providers, however studies have shown that in patients' hands peak flow is the better indicator of control. Contrary to this view is an excellent study from Indiana that used quality of life scores for their ability to predict exacerbations of asthma. The investigators identified adults who received oral or inhaled asthma medications from 36 community pharmacies and administered the McMaster Asthma Quality of Life Questionnaire (AQLQ). They also measured PEFR, defining "red zone" (highest risk) as a PEFR < 50% of each patient's expected value based on gender, age, and height. A red zone PEFR was a significant predictor of exacerbations within 12 months, however, neither a red zone PEFR, the raw PEFR, or percent of predicted maximal PEFR were significantly predictive when controlling for AQLQ scores, clinical chaacteristics, or demographic data. On the other hand, the four subscales of the AQLQ were each significant predictors of asthma exacerbations. For example, the overall AQLQ scale predicted a 63% risk of exacerbations occurring within 4 months and 66% within 12 months. Their conclusion therefore was that PEFR added no predictive information to that contained in AQLQ scores and clinical and demographic data. This study has implications for patients and doctors, demonstrating not only the general importance of a good history, but also the value of using a tool that comprehensively measures quality of life

Read more:
J Gen Intern Med. 2004;19:237-42
J Clin Pharm Ther. 2001;26:287-96