Table 6.
Characteristics of the Initial Eligible and Enrolled Patients
| Patient characteristic | All eligible (N=1428) | Enrolled with baseline forms complete (N=796) |
|---|---|---|
| Age at screening/enrollment, years | ||
| Mean (SD) | 54 (15) | 54 (14) |
| Median (range) | 56 (18–90) | 55 (18–89) |
| 18-29, % | 7% | 7% |
| 30-39, % | 10% | 9% |
| 40-49, % | 17% | 18% |
| 50-59, % | 26% | 29% |
| 60-69, % | 25% | 24% |
| 70-79, % | 13% | 12% |
| ≥80, % | 2% | 1% |
| Age at asthma diagnosis, years | ||
| Mean (SD) | 29 (21) | 28 (21) |
| Median (range) | 27 (0–80) | 26 (0–80) |
| <12, % | 27% | 32% |
| 12-20, % | 12% | 10% |
| >20, % | 52% | 56% |
| NR | 9% | 2% |
| Duration of subspecialty care for asthma, years | ||
| Time since first subspecialist visit for asthma | ||
| Mean (SD) | NA | 18.5 (17.8) |
| Median (range) | 12.2 (0–87) | |
| Time since first visit with current subspecialist | ||
| Mean (SD) | NA | 7.2 (7.9) |
| Median (range) | 4.6 (0–58) | |
| Female sex, % | 68% | 67% |
| Race/ethnicity, % | ||
| Non-Hispanic White | NA | 71% |
| Non-Hispanic Black | 16% | |
| Hispanic | 8% | |
| Asian | 2% | |
| American Indian or Alaska Native | 1% | |
| Other | 2% | |
| NR | 3% | |
| BMI (kg/m2) | ||
| Mean (SD) | NA | 33 (8) |
| Median (range) | 31 (16–70) | |
|
Regularly exposed to allergens known to exacerbate asthma, %a Yes |
NA |
62% |
| No | 31% | |
| Unknown | 6% | |
| Smoking status | ||
| Current smoker, % | NA | 3% |
| Pack-year history for current smokers, mean, median | 12.7, 7.5 | |
| Former smoker, % | NA | 29% |
| Pack-year history for former smokers, mean, median | 12.3, 6.8 | |
| Residential setting, % | ||
| Rural | NA | 22% |
| Suburban | 50% | |
| Urban | 26% | |
| Not reported | 2% | |
| Insurance status, %b | ||
| Commercial: No PCP referral required | 46% | 48% |
| Commercial: PCP referral required | 14% | 16% |
| Medicare | 23% | 22% |
| Medicaid | 10% | 9% |
| Other government insurance (eg, Tricare, VA, etc.) | 1% | 2% |
| Other | 4% | 3% |
| Uninsured | 2% | 1% |
| First degree relative with asthma, % | NA | 45% |
|
Asthma treatment categoryb High-dosage ICS with additional controllers, no biologics or mSCS |
37% |
19%c |
| Biologics, no mSCS | 51% | 67% |
| Biologics and mSCS | 7% | 9% |
| mSCS, no biologics | 5% | 4% |
| Biologics used among those receiving biologics, %b | ||
| Omalizumab | NA | 54% |
| Mepolizumab | NA | 24% |
| Benralizumab | NA | 18% |
| Reslizumab | NA | 5% |
| Dupilumab | NA | 1% |
| Exacerbationsd in the 12 months prior to enrollment | ||
| ≥1 exacerbation, % | 61% | 65% |
| ≥1 exacerbation resulting in hospitalization, % | NA | 12% |
| Mean overall, n | 1.9 | 2.0 |
| Mean among those with any exacerbation, n | 3.0 | 3.2 |
| Provider-reported GINA asthma symptom control assessment as of last visit prior to enrollment, %e | ||
| Daytime symptoms more than twice per week | NA | 54% |
| Nocturnal awakening/symptoms | NA | 40% |
| Asthma reliever use more than twice per week | NA | 55% |
| Activity limitation due to asthma | NA | 55% |
| Most recent pulmonary function testing, median percent predicted | ||
| FEV1 / FVC | ||
| Regardless of bronchodilator withhold (n=697 / n=699) | NA | 75% / 79% |
| With bronchodilator withhold (n=238 / n=238) | NA | 70% / 78% |
| Without bronchodilator withhold (n92 / n=93)f | NA | 78% / 81% |
|
Most recent laboratory results for relevant biomarkers Mean / median blood eosinophil count (per µL) from CBC (n=359) |
NA |
287 / 152 |
| Mean / median total immunoglobulin E (IU/mL) (n=360) | NA | 580 / 202 |
| Mean / median fractional exhaled nitric oxide (ppb) (n=244) | NA | 36 / 25 |
Notes: Fields marked NA represent data that were not collected for nonenrolled patients. an=10 (1.3%) patients had missing values. bPercentages may not total 100.0% due to rounding. cPer protocol, there was systematic undersampling of this population; sites approached every third patient in this category due to anticipated greater prevalence. dAggregate count reported at screening. An exacerbation was defined as a worsening of asthma that required systemic corticosteroids for ≥3 days (or a single depo-injectable dose), an urgent care or emergency room visit requiring systemic corticosteroids due to asthma, or an inpatient hospitalization due to asthma. Ten or more exacerbations were counted as 10 for calculation of mean. eSites described symptoms as of the patient’s most recent visit. Additionally, 7–17% of patients had “unknown” as a reported value and were excluded from the reported percentages. fn=366 and n=367 patients had unknown status regarding bronchodilator withhold for % predicted FEV1 and FVC, respectively. These patients are included in the “regardless of bronchodilator withhold” population but excluded from the subgroups with known status for bronchodilator withhold.
Abbreviations: BMI, body mass index; CBC, complete blood count; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; GINA, Global Initiative for Asthma; ICS, inhaled corticosteroids; IgE, immunoglobulin E; mSCS, maintenance systemic corticosteroids; NR, not reported; PCP, primary care physician; ppb, parts per billion; SD, standard deviation; VA, Veterans Affairs.