An Attempted Prospective Testing of an Asthma Severity Index and a Quality of Life Survey for 1 Year in Ambulatory Patients with Asthma

It has been recommended that allergist-immunologists use quality of life (QOL) surveys to document their "added value" in patient care. There are little cross-sectional or prospective data regarding longer term follow-up of patients using QOL assessments and none associated with prospective use of an asthma severity index (ASI). Our objective was to identify clinical and psychological correlates of adverse asthma outcomes as assessed using the ASI survey. A 12 item QOL and a nine item ASI survey, spirometry, and history and physical were obtained from patients initially and then every 3 months for a year. The ASI was calculated as follows: one point for each emergency treatment of asthma if not in status asthmaticus, three points for each hospitalization for status asthmaticus, and six points for each intensive care admission or intubation. Patients were 56 adults between ages 18 and 45 with asthma enrolled between May 1994 and February 1996 with the intention to be reassessed quarterly for a year. At enrollment the 56 patients had ASI scores for the previous 12 months ranging from zero to 30. The patient with an ASI of 30 did not return after the initial visit. Of the 13 patients who completed the study, 12 patients had a zero ASI score over a 12-month period; one patient who had an initial score of 26 finished with a score of one. There were no deaths throughout the follow-up period. Of the 43 patients who did not complete the study only six (13.9%) cited local managed care or primary care physician as taking over their care. Initial ASI scores were dichotomized (zero versus greater-than-zero) due to skewness. The forced expiratory volume in one second (FEVl), % predicted FEV1 and peak flow were not related significantly to the dichotomized ASI score. The strongest univariate predictor was the self-assessment of asthma burden using a 78 mm visual analog scale. A two variable model included a query about bodily pain in the last 4 weeks and a self-assessment of general health. The dropout rate was high but only 13.9% of such patients reported that managed care or primary care physicians were responsible. A two variable model was a strong predictor of asthma severity. The single best predictor of asthma severity was a visual analog scale based on the question "How do you think your asthma is?"