Reliever-Triggered Inhaled Glucocorticoid in Black and Latinx Adults with Asthma

Abstract

Background: Black and Latinx patients bear a disproportionate burden of asthma. Efforts to reduce the disproportionate morbidity have been mostly unsuccessful, and guideline recommendations have not been based on studies in these populations.

Methods: In this pragmatic, open-label trial, we randomly assigned Black and Latinx adults with moderate-to-severe asthma to use a patient-activated, reliever-triggered inhaled glucocorticoid strategy (beclomethasone dipropionate, 80 μg) plus usual care (intervention) or to continue usual care. Participants had one instructional visit followed by 15 monthly questionnaires. The primary end point was the annualized rate of severe asthma exacerbations. Secondary end points included monthly asthma control as measured with the Asthma Control Test (ACT; range, 5 [poor] to 25 [complete control]), quality of life as measured with the Asthma Symptom Utility Index (ASUI; range, 0 to 1, with lower scores indicating greater impairment), and participant-reported missed days of work, school, or usual activities. Safety was also assessed.

Results: Of 1201 adults (603 Black and 598 Latinx), 600 were assigned to the intervention group and 601 to the usual-care group. The annualized rate of severe asthma exacerbations was 0.69 (95% confidence interval [CI], 0.61 to 0.78) in the intervention group and 0.82 (95% CI, 0.73 to 0.92) in the usual-care group (hazard ratio, 0.85; 95% CI, 0.72 to 0.999; P = 0.048). ACT scores increased by 3.4 points (95% CI, 3.1 to 3.6) in the intervention group and by 2.5 points (95% CI, 2.3 to 2.8) in the usual-care group (difference, 0.9; 95% CI, 0.5 to 1.2); ASUI scores increased by 0.12 points (95% CI, 0.11 to 0.13) and 0.08 points (95% CI, 0.07 to 0.09), respectively (difference, 0.04; 95% CI, 0.02 to 0.05). The annualized rate of missed days was 13.4 in the intervention group and 16.8 in the usual-care group (rate ratio, 0.80; 95% CI, 0.67 to 0.95). Serious adverse events occurred in 12.2% of the participants, with an even distribution between the groups.

Conclusions: Among Black and Latinx adults with moderate-to-severe asthma, provision of an inhaled glucocorticoid and one-time instruction on its use, added to usual care, led to a lower rate of severe asthma exacerbations. (Funded by the Patient-Centered Outcomes Research Institute and others; PREPARE ClinicalTrials.gov number, NCT02995733.).

Figure 1.. Mean Cumulative Number of Severe Asthma Exacerbations per Participant over Time, with Adjusted Hazard Ratio.

Shown are the mean cumulative numbers of severe asthma exacerbations per participant over time. Participants in the intervention group received patient-activated, reliever-triggered inhaled glucocorticoid in addition to usual care. Differences in treatment-group hazards were compared with the use of the Andersen–Gill model with adjustment for prespecified covariates.

Figure 2.. Mean Changes from Baseline in Asthma-Related Scores.

The least-squares mean differences between treatment groups in the changes from baseline in asthma-related scores were calculated with the use of a mixed model. The Asthma Control Test (Panel A) is a participant-administered tool for assessing the level of asthma control. Total scores range from 5 to 25, with a score of 20 to 25 indicating well-controlled asthma, a score of 16 to 19 indicating asthma that was not well controlled, and a score of 5 to 15 indicating very poorly controlled asthma; the minimal clinically important difference is 3 points. The Asthma Symptom Utility Index (Panel B) is a participant-administered tool for assessing preference-based quality of life. The summary score is on a continuous scale, ranging from 0 (worst possible symptoms) to 1 (no symptoms); the minimal clinically important difference is 0.09. I bars indicate 95% confidence intervals. The widths of the confidence intervals have not been adjusted for multiplicity and cannot be used to infer treatment effects.

Figure 3. Subgroup Analyses of Severe Asthma Exacerbation Outcome.

The forest plot shows the risk of severe asthma exacerbations in selected prespecified subgroups. The widths of the confidence intervals have not been adjusted for multiplicity and cannot be used to infer treatment effects. Race was reported by the participant; those who identified as both Black and Latinx were classified as Latinx. Nonsmokers were those who had not smoked within the previous year and had smoked less than 10 pack-years. The participant’s attitude toward asthma medications was assessed with the Beliefs about Medicines Questionnaire; the “accepting” category indicates that the participant believed the therapy was of high necessity and low concern. Depressive status was assessed with the Patient Health Questionnaire–2; scores range from 0 to 6, with a score of 3 or higher indicating depression. The Brief Health Literacy Scale measures participant-reported health literacy and consists of three items. If a participant’s response on any item indicated low or marginal health literacy, the participant was considered to have low or marginal health literacy; otherwise, health literacy was considered to be high. The body-mass index is the weight in kilograms divided by the square of the height in meters. Participant-reported medication adherence was assessed with the Medication Adherence Report Scale–5 by the calculation of the mean score over the five items. Mean scores range from 1 to 5, with higher scores indicating better adherence. FeNO denotes fraction of exhaled nitric oxide, LABA long-acting β₂-agonist, and ppb parts per billion.