Black Patients Entered Asthma Biologic Care With Worse Lung Function and More Missed Visits
Racial differences appeared early in the pathway to biologic therapy for asthma, before any treatment response could even be judged. In a retrospective review of patients who started biologics for moderate to severe asthma between January 1, 2019, and June 30, 2022, Black or African American patients entered treatment with poorer lung function than White patients and showed less consistent clinic engagement. The pattern points to a familiar but still unresolved problem in asthma care: advanced therapy may be available on paper, yet the patients who may need it most often reach it later, with greater disease burden already in place.
The cohort included 215 patients, most of whom were White (69%) or Black or African American (27%). Insurance coverage was largely commercial (54%) or Medicare (22%), placing the study in a real-world outpatient setting rather than a tightly controlled trial population. Investigators looked at race, socioeconomic factors, baseline asthma severity at the time of biologic initiation, and whether those characteristics were associated with response within 18 months of starting therapy. They also examined racial differences in clinic engagement, healthcare utilization, and biologic adherence. Lung function was measured using race-neutral percent predicted forced expiratory volume in one second, or ppFEV1, a choice that matters because it removes one layer of historical bias from interpretation while still capturing clinically meaningful airflow limitation.
At biologic initiation, Black or African American and other non-White patients were estimated to have a 6.9% lower ppFEV1 than White patients. The difference approached statistical significance, with a p value of 0.057. In practical terms, that means many Black patients reached specialty biologic treatment already starting from a worse respiratory baseline, which can reflect delayed referral, higher cumulative inflammatory burden, uneven access to specialist care, or all three at once. Asthma biologics are designed to blunt type 2 inflammation, but they cannot erase the consequences of years of uncontrolled disease that have already narrowed airway reserve.
One sentence captures the clinical tension: the door to advanced care opened, but not at the same point for everyone.
Missed appointments added another layer. Black or African American patients had a higher percentage of no-show appointments than White patients, signaling weaker clinic engagement during the treatment course. In severe asthma, that is not a minor administrative inconvenience. Biologic therapy usually depends on repeated visits for prescribing, monitoring, dose continuity, and reinforcement of inhaler technique, trigger avoidance, and adherence. When appointments are missed, the treatment pathway becomes fragmented, and the chance to detect early response or troubleshoot poor control drops quickly.
The study also evaluated adherence using proportion of days covered, a standard pharmacy-based measure that can reveal how consistently a patient actually receives medication after prescription. In biologic therapy, adherence is especially important because the drugs are costly, administratively complex, and often administered on scheduled intervals. Even when the medication itself works, the system around it can fail if refills are delayed, prior authorizations stall, transportation is unreliable, or follow-up is inconsistent. Those barriers tend to fall hardest on patients facing structural disadvantage, and asthma outcomes follow the same social gradient seen across many chronic diseases.
The investigators used multiple linear regression to examine whether race and socioeconomic status were associated with ppFEV1 before prescription and within 18 months after biologic initiation. That design makes the study useful for identifying real-world differences, though it cannot prove why those differences exist. Still, the clinical implications are hard to ignore. Patients do not arrive at biologic therapy in a vacuum; they arrive after years of exposure to environmental triggers, inconsistent access to preventive care, underrecognized severity, and repeated exacerbations. For severe asthma, those forces can shape who gets referred, who stays engaged, and who benefits from treatment in the first place.
There is also an important measurement issue behind the numbers. Race-neutral ppFEV1 helps reduce one source of distortion in pulmonary assessment, but it does not address the social and healthcare-system barriers that may produce worse baseline status in the first place. If Black patients begin biologic therapy with lower lung function and more missed visits, then a later comparison of response may confound pharmacologic effect with access and follow-up patterns. In other words, the treatment can only be evaluated fairly if the pathway to treatment is fair as well.
This study places real-world asthma biologic use under a sharper lens. It shows that inequity can appear before treatment starts, persist during follow-up, and shape the odds of meaningful benefit. The unanswered operational question is how to close those gaps at the point of referral, scheduling, insurance navigation, and longitudinal support so biologic therapy reaches patients before disease becomes more entrenched.