Table 1.
Characteristics of the Participants at Baseline.*
| Characteristic | Intervention Group (N = 600) | Usual-Care Group (N = 601) | Total (N = 1201) |
|---|---|---|---|
| Race and ethnic group — % | |||
| Black | 50.5 | 49.9 | 50.2 |
| Latinx | 49.5 | 50.1 | 49.8 |
| Both Black and Latin† | 6.3 | 4.3 | 5.3 |
| Age — yr | 48.3±13.5 | 47.0±13.9 | 47.7±13.7 |
| Female sex assigned at birth — % | 84.7 | 82.7 | 83.7 |
| Body-mass index‡ | 35.2±9.1 | 35.1±9.5 | 35.1±9.3 |
| Obesity — %‡ | 70.2 | 67.1 | 68.6 |
| Smoking status — %§ | |||
| Current smoker | 11.5 | 12.3 | 11.9 |
| Former smoker | 9.0 | 7.7 | 8.3 |
| Nonsmoker or former smoker in smoking environment — %¶ | 16.0 | 17.8 | 16.9 |
| No. of pack-yr of smoking | 12.4 | 15.8 | 14.1 |
| Maintenance asthma medications — % | |||
| Inhaled glucocorticoid without LABA | 28.5 | 28.1 | 28.3 |
| Combination inhaled glucocorticoid with LABA | 71.3 | 71.7 | 71.5 |
| Long-acting muscarinic antagonist | 10.7 | 13.1 | 11.9 |
| Leukotriene-receptor antagonist | 51.3 | 48.3 | 49.8 |
| Biologic agent∥ | 2.8 | 3.2 | 3.0 |
| Quick-reliever nebulizer use | |||
| Use of quick-reliever nebulizer — % | 68.0 | 65.9 | 66.9 |
| No. of quick-reliever nebulizations per week | 2.7±4.6 | 3.0±4.8 | 2.9±4.7 |
| No. of coexisting conditions — %** | |||
| 0 | 27.7 | 31.8 | 29.7 |
| 1 | 25.0 | 21.0 | 23.0 |
| 2 | 22.2 | 19.8 | 21.0 |
| 3 | 13.5 | 14.3 | 13.9 |
| ≥4 | 11.7 | 13.1 | 12.4 |
| FeNO — ppb | 26.7±27.8 | 30.4±34.9 | 28.6±31.6 |
| Absolute eosinophil count — cells/mm3 | |||
| Mean | 246±229 | 250±247 | 248±238 |
| Median | 188 | 195 | 192 |
| ≥1 Asthma exacerbation in past year — %†† | 73.3 | 71.0 | 72.2 |
| Asthma Control Test score‡‡ | 14.7±4.4 | 14.5±4.5 | 14.6±4.4 |
| Asthma Symptom Utility Index score§§ | 0.67±0.22 | 0.67±0.21 | 0.67±0.21 |
| Medication Adherence Report Scale-5 score¶¶ | 4.2±0.8 | 4.2±0.8 | 4.2±0.8 |
| Low or marginal health literacy — %∥∥ | 16.9 | 16.6 | 16.8 |
| Participant-perceived overall health — % | |||
| Excellent | 2.2 | 1.5 | 1.8 |
| Very good | 11.3 | 10.0 | 10.7 |
| Good | 33.3 | 32.3 | 32.8 |
| Fair | 42.8 | 45.3 | 44.0 |
| Poor | 10.3 | 11.0 | 10.7 |
Plus–minus values are means ±SD. Participants in the intervention group received patient-activated, reliever-triggered inhaled glucocorticoid (beclomethasone dipropionate, 80 μg) added to usual care. All the baseline characteristics listed here were reported by the participant except for fraction of exhaled nitric oxide (FeNO) and absolute eosinophil count. Data on FeNO were missing for 98 participants in the intervention group and for 100 participants in the usual-care group, and data on the absolute eosinophil count were missing for 98 and 107, respectively. Percentages may not total 100 because of rounding. LABA denotes long-acting β2-agonist, and ppb parts per billion.
Participants who identified as both Black and Latinx were classified as Latinx for the purpose of stratification.
The body-mass index is the weight in kilograms divided by the square of the height in meters. Obesity was defined as a body-mass index of 30 or higher.
Current smokers were defined as participants who were currently smoking or had smoked within the previous year. Former smokers were participants who had not smoked in the previous year but had smoked at least 10 pack-years. Nonsmokers were those who had not smoked within the previous year and had smoked less than 10 pack-years.
A smoking environment was defined as others regularly smoking in the participant’s home, work, or car.
Biologic agents included injectable monoclonal antibody therapies targeting IgE, interleukin-5 or the interleukin-5 receptor, or the interleukin-4 receptor.
Coexisting conditions included heart disease, cancer (except skin cancer), stroke, diabetes, chronic kidney disease, chronic obstructive pulmonary disease, human immunodeficiency virus infection or acquired immunodeficiency syndrome, hypertension, depression, and sleep disorder.
Asthma exacerbation in the previous year was defined as a participant-reported emergency department or urgent care visit, hospitalization, or course of systemic glucocorticoids within the 12 months before randomization.
The Asthma Control Test is a participant-administered tool for assessing the level of asthma control.23 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.23,24 The minimal clinically important difference is 3 points.25
The Asthma Symptom Utility Index is a participant-administered tool for assessing preference-based quality of life.26 Scores range from 0 (worst possible symptoms) to 1 (no symptoms). The minimal clinically important difference is 0.09.27
The Medication Adherence Report Scale–5 measures participant-reported medication adherence. Mean scores are calculated from five items and range from 1 to 5, with higher scores indicating better adherence.31
Health literacy was assessed with the Brief Health Literacy Scale, which measures participant-reported health literacy and consists of three items. Scoring low or marginal health literacy on any one item classifies a participant as having low or marginal health literacy.32