Association of Inhaled Corticosteroid and Long-Acting Beta Agonist Combination Versus Inhaled Corticosteroid Only Inhalers on Adherence and Asthma Outcomes.

BACKGROUND

Despite asthma being one of the most common chronic conditions among children in the United States, real-world evidence on medication adherence and healthcare utilization in underserved pediatric populations remains limited. Therefore, we aim to evaluate adherence, persistence, and asthma-related healthcare utilization among Medicaid-enrolled children receiving inhaled corticosteroids (ICS) versus ICS-long-acting beta-agonist (ICS-LABA) inhalers.

METHODS

We conducted a retrospective cohort study using Texas Children's Health Plan claims data from 2016 to 2019. Children aged 4-17 years with asthma diagnoses and ≥1 prescription for an ICS or ICS-LABA were included. Adherence was determined as the proportion of days covered (PDC) of ≥ 50%, and persistence was defined as continuous therapy without a 60-day gap. The PDC ≥ 80% was evaluated in sensitivity analysis. Multivariable logistic regression was used to estimate adherence, asthma-related emergency department (ED) visits, and hospitalizations.

RESULTS

Among 8622 eligible children, 82.4% received ICS and 17.6% received ICS-LABA. In inverse probability of treatment weighting (IPTW) adjusted analyses, compared with ICS, ICS-LABA users had higher adherence rate i.e., 21.08% versus 16.56% achieved PDC ≥ 50% (aOR = 1.35; 95%CI: 1.25-1.45), and 10.82% versus 6.74% achieved PDC ≥ 80% (aOR = 1.61; 95%CI: 1.31-1.97). Refill persistence was also higher with ICS-LABA (36.16% vs. 23.35%, aOR: 1.86, 95%CI: 1.74-1.99). However, despite better adherence, we found ICS-LABA users exhibited greater asthma-related healthcare utilization, i.e., ED visits occurred in 18.69% versus 11.25% (aOR = 1.81; 95%CI: 1.56-2.11) and hospitalizations in 2.53% versus 1.00% (aOR= 2.55; 95%CI: 1.68-3.89), which persisted even after adjusting for adherence.

CONCLUSIONS

We found that adherence was greater in children with asthma who were dispensed an ICS-LABA as compared to those dispensed an ICS-only inhaler; however, adherence rates were low in both groups. Higher hospitalization and ED visit rates among those prescribed ICS-LABA therapy likely reflect higher disease severity in this group. Our findings should be interpreted in light of claims-based adherence measures and potential residual confounding due to unmeasured asthma severity and control.