Adherence to Asthma Biologics: Implications for Patient Selection, Step Therapy, and Outcomes.

BACKGROUND

Little is known about adherence to asthma biologics.

RESEARCH QUESTION

Is adherence to inhaled corticosteroid (ICS) associated with subsequent asthma biologic adherence?

STUDY DESIGN AND METHODS

We analyzed individuals with asthma who started asthma biologics in the OptumLab Data Warehouse and used that data until October 2019. We calculated proportion days covered (PDC) for ICS ± long-acting β-agonists in the 6 months before and after asthma biologics were started and asthma biologic PDC for the first 6 months of use. We performed a multivariable analysis to identify factors associated with asthma biologic PDC ≥0.75, ICS PDC ≥0.75 during the 6-month period after asthma biologic were started, and achievement of a ≥50% reduction in asthma exacerbations during the first 6 months of asthma biologic use.

RESULTS

We identified 5,319 people who started asthma biologics. The mean PDC for asthma biologics was 0.76 (95% CI, 0.75-0.77) in the first 6 months after starting, higher than the mean PDCs for ICS in the 6 months before (0.44 [95% CI, 0.43-0.45]) and after (0.40 [95% CI, 0.39-0.40]) starting the asthma biologic. PDC ≥0.75 for ICS 6 months before index biologic use is associated with PDC for asthma biologics ≥0.75 (OR, 1.25; 95% CI, 1.10-1.43) and for ICS during the first 6 months of biologic use (OR, 9.93; 95% CI, 8.55-11.53). Neither ICS PDC ≥0.75 (OR, 0.92; 95% CI, 0.74-1.14) nor asthma biologic PDC ≥0.75 (OR, 1.15; 95% CI, 0.97-1.36) is associated with a statistically significant reduction in asthma exacerbations during the first 6 months of asthma biologic use among people with any exacerbation in the 6 months before first use.

INTERPRETATION

Adherence to asthma biologic is higher than to ICS and is associated with different factors.