Background: The most widely used performance measure for asthma, the Health Plan Employer Data and Information Set (HEDIS), has been criticized because the delay between classification (year 1) and assessment of medication dispensing (year 2) may produce a "misalignment" and weaken the validity of the measure.
Objective: To examine whether a previously observed association between the HEDIS performance measure and asthma-related emergency department visits is robust when the period between the classification and outcome assessment is evaluated during a 2-year period as defined.
Methods: Children (N = 2766) aged 3 to 15 years enrolled in 1 of 3 managed care organizations with at least 1 asthma diagnosis listed for a hospitalization, an emergency department visit, or an ambulatory encounter and at least 2 consecutive years of data for analysis from July 1996 through June 1999 were identified.
Results: Children did not consistently meet the HEDIS criteria for persistent asthma, and 24% to 28% of children did not requalify in year 2 of observation. Multivariate regression models showed that a protective relationship between controller medication dispensing and asthma-related emergency department visits was no longer seen among children meeting the HEDIS criteria for persistent asthma when the total period of observation is extended to 2 years (odds ratio, 0.7; 95% confidence interval, 0.4-1.2).
Conclusions: Our results suggest that the variable nature of asthma may affect how the HEDIS performance measure should be used for assessing quality of care. The period between identification of the target population and performance assessment should be closely related in time.