Process quality measures and asthma exacerbations in the medicaid population.

BACKGROUND

Asthma quality assessment often focuses on controller medication use, yet claims-based studies find conflicting associations between this care process and clinical outcomes.

OBJECTIVE

We sought to compare the association between 3 controller-based quality measures and asthma exacerbations to gain better understanding of how processes of care are related to clinical outcomes.

METHODS

Identifying a cohort of Medicaid beneficiaries with persistent asthma by using Healthcare Effectiveness Data and Information Set (HEDIS) criteria for asthma in 2001-2002 in California and New York, we assessed 3 asthma quality metrics in 2002: (1) the current HEDIS measure of at least 1 controller medication filling; (2) at least 4 controller medication prescription fillings; and (3) a controller-to-total asthma medication ratio of at least 0.5. We calculated the odds of having an asthma exacerbation in 2003 as a function of performance on each quality metric, adjusting for race, sex, age, and prior outpatient and acute care use for asthma.

RESULTS

Of 90,909 subjects with persistent asthma in California (48.1%) and New York (51.9%), those who obtained at least 1 or at least 4 controller medications had increased likelihood of poor outcomes (adjusted odds ratios, 1.80 [95% CI, 1.73-1.87] and 1.44 [95% CI 1.40-1.48], respectively). Beneficiaries meeting the controller-to-total asthma medication ratio measure were 23.0% less likely to have exacerbations (adjusted odds ratio, 0.77 [95% CI, 0.75-0.80]).

CONCLUSIONS

A higher controller medication ratio indicated a lower likelihood of asthma exacerbations, whereas assessing the number of controller medication-dispensing events was associated with a higher odds of exacerbation.