Measurement of utility in asthma: evidence indicating that generic instruments may miss clinically important changes.

Sullivan, Patrick; Ghushchyan, Vahram; Campbell, Jonathan; Globe, Gary; Bender, Bruce; Magid, David; Sullivan, Patrick W; Ghushchyan, Vahram H; Campbell, Jonathan D; Magid, David J

Background: Accurate assessment of preference-based health-related quality of life is important in determining the value of asthma interventions.Objective: To examine the sensitivity and responsiveness of the EQ-5D and the AQL-5D to differences in asthma control measured by the Asthma Control Questionnaire (ACQ-5).Methods: The Observational Study of Asthma Control and Outcomes was a prospective survey of persistent asthma patients ≥12 years old in Kaiser Colorado. Patients received a survey three times in 1 year, including the ACQ-5, AQL-5D and EQ-5D-3L (including VAS). Censored Least Absolute Deviations (CLAD) and logistic regression were used, controlling for sociodemographics and smoking.Results: There were 6666 completed surveys (1799 individuals completed all three survey waves). After controlling for covariates, each one-point increase in ACQ-5 was associated with a decrease of 0.066, 0.058, 0.074 and 6.12 in EQ-5D(US), EQ-5D(UK), AQL-5D and VAS scores. Uncontrolled asthma (ACQ-5 > 1.5) was associated with a decrease of 0.15, 0.17, 0.11 and 10, respectively (vs. ACQ ≤ 1.5). AQL-5D scores were statistically significantly different across categories of ACQ-5 scores of 0.5 (the minimum clinically important difference [MCID]), while EQ-5D scores were not significant across most categories. The AQL-5D appeared more robust to changes in control over time (responsiveness) compared to EQ-5D-3L.Conclusion: The AQL-5D appears more responsive to changes in asthma control over time and more sensitive to detecting differences corresponding to the ACQ-5 MCID than the EQ-5D-3L. Using the EQ-5D-3L without an asthma-specific measure such as the AQL-5D may miss clinically important changes in asthma control.

QUALITY of life; ASTHMA treatment; ASTHMATICS; QUESTIONNAIRES; SOCIODEMOGRAPHIC factors; PHYSIOLOGY; ASTHMA diagnosis; MENTAL health; LONGITUDINAL method

Quality of Life Research, 2016, Vol 25, Issue 12, p3017

0962-9343

Academic Journal

10.1007/s11136-016-1357-8