William W. Crawford

The Relationship of Asthma Impairment Determined by Psychometric Tools to Future Asthma Exacerbations

BACKGROUND Impairment and risk are considered separate domains of asthma control, but relationships between them are not completely understood. We compared three validated questionnaires reflecting asthma impairment in their ability to predict future exacerbations. METHODS Two thousand six hundred eighty patients with persistent asthma completed a survey that included the Asthma Control Test (ACT), mini-Asthma Quality of Life Questionnaire (mAQLQ), and Asthma Impact Survey (AIS-6), as well as a history of exacerbations in the prior 12 months. An exploratory factor analysis was performed using the questions of the three tools, and individual patient factor scores were calculated. Independent relationships between predictors (tools and factors) and exacerbations the following year captured from administrative data were evaluated. RESULTS Each tool was significantly related (P < .0001) to future exacerbations above and beyond the risk conferred by prior exacerbations (relative risk [RR] = 1.3). When prior exacerbations were included in the model, the three impairment tools provided similar and overlapping information, such that only the mAQLQ entered the model (RR = 1.3; 95% CI, 1.1-1.5). Factor analysis revealed three factors (symptoms, activity, and bother) that were each significantly associated (P < .0001) with future asthma exacerbations. However, only the activity factor was independently related to future exacerbations. CONCLUSIONS Asthma impairment is significantly related to the risk of future exacerbations, but the ACT, mAQLQ, and AIS-6 do not provide independent information from each other in this regard. Interference with activities is the primary subjective component of asthma impairment that is related to the risk of future exacerbations.

Association of exhaled nitric oxide to asthma burden in asthmatics on inhaled corticosteroids.

Background. Fractional exhaled nitric oxide (FENO) is a marker of airway inflammation. Its role in assessing asthma burden in clinical practice needs more study. Objective. To determine whether higher FENO levels are associated with greater asthma burden. Methods. This was a multicenter cross-sectional retrospective study of atopic 12- to 56-year-old persistent asthmatics on inhaled corticosteroids (ICS). Questionnaire and 1-year retrospective administrative data were used to analyze by unadjusted and adjusted robust Poisson regression (relative risks) and negative binomial regression [incidence rate ratios (IRRs)] the associations of masked FENO levels (NIOX MINO®) to short-acting beta-agonist (SABA) dispensings and oral corticosteroid (OCS) use in the past year independent of spirometry and an asthma control tool [Asthma Control Test (ACT)]. Results. FENO levels ranged from 7–215ppb (median 28ppb) in 325 patients. Higher FENO levels significantly correlated with more SABA dispensings and OCS courses in the past year, lower FEV1% predicted levels, but not ACT score. FENO highest (≥48ppb) versus lowest (≤19ppb) quartile values were associated independently in the past year with ≥7 SABA canisters dispensed (relative risk=2.40, 95% CI=1.25–4.62) and total number of SABA canisters dispensed (IRR=1.46, 95% CI=1.12–1.99) and with ≥1 OCS course (relative risk=1.48, 95% CI=1.06-2.07) and total number of OCS courses (IRR=1.71, 95% CI=1.09–2.66). The significant independent relationship of higher FENO levels to increasing SABA dispensings and OCS courses was confirmed by linear trend analyses. Conclusions. Independent and clinically meaningful associations between higher FENO levels and greater asthma burden during a prior year in persistent asthmatics on ICS suggest that FENO measurement may be a complementary tool to help clinicians assess asthma burden.

Change in Asthma Control Over Time: Predictors and Outcomes

BACKGROUND Maintenance of asthma control over time is a clear goal of national asthma guidelines, but few studies have addressed the natural history of asthma control over time. OBJECTIVE To assess the impairment domain of asthma control over time in patients with persistent asthma and to determine predictors and consequences of controlled and uncontrolled asthma over time. METHODS Patients 18-56 years old with persistent asthma who completed baseline (November 2007) and follow-up asthma surveys (April, July, October 2008) were included in the study. The survey included the Asthma Control Test as well as questions regarding other patient and asthma characteristics. Health care utilization (pharmacy and exacerbations) for 2008 was obtained from administrative data. RESULTS The baseline and first follow-up surveys were completed by 1267 patients, and all 4 surveys were completed by 782 patients. Patients with well-controlled asthma at baseline were significantly more likely (P < .0001) to have well-controlled asthma over the following year (76.2%-80.4%) than patients with uncontrolled asthma at baseline (33.5%-36.9%). Patients whose asthma control improved over the first several months of follow-up experienced significantly (P < .05) fewer exacerbations over the subsequent year than patients with initially uncontrolled asthma who did not improve. CONCLUSION Degree of asthma control at one point in time is strongly related to the achievement or maintenance of control and to asthma exacerbations over time. Patients with uncontrolled asthma, especially very poorly controlled asthma, should receive intensive management and follow-up in an attempt to achieve well-controlled asthma over time.

The HEDIS Medication Management for People with Asthma Measure is Not Related to Improved Asthma Outcomes

BACKGROUND A new Healthcare Effectiveness Data and Information Set (HEDIS) asthma quality-of-care measure designed to quantify patient adherence to asthma controller medication has been implemented. The relationship between this measure and asthma outcomes is unknown. OBJECTIVE To examine the relationship between the HEDIS Medication Management for people with Asthma (MMA) measure and asthma outcomes. METHODS Administrative data identified 30,040 patients who met HEDIS criteria for persistent asthma during 2012. These patients were classified as compliant or noncompliant with the MMA measure at the 75% and 50% threshold, respectively. The association between MMA compliance in 2012 and asthma outcomes in 2013 was determined. RESULTS Patients who were 75% or 50% MMA compliant in 2012 showed no clinically meaningful difference in asthma-related hospitalizations, emergency department visits, or rescue inhaler dispensing in 2013 compared with those who were noncompliant. Stepwise comparison of patients who were 75% or more, 50% to 74%, and less than 50% MMA compliant showed no meaningful difference in asthma outcomes between groups. CONCLUSIONS Compliance with the HEDIS MMA measure is not related to improvement in the asthma outcomes assessed (rescue inhaler dispensing, asthma-coded hospitalizations, or asthma-coded emergency department visits).