Table 4.
Effects of ICS on risk for exacerbation during 1-year follow-up in patients with ACO.
| Case/n | Frequency (mean ± SD) | Unadjusted IRR (95% CI) | Adjusted IRR (95% CI) | ||
|---|---|---|---|---|---|
| Model 1 | Model 2 | ||||
| Moderate to severe AE | |||||
| Total | 196/506 | 0.85 ± 1.58 | 0.82 (0.63–1.07) | 0.75 (0.57–0.98)* | 0.75 (0.57–0.98)* |
| NHW | 53/188 | 0.48 ± 0.72 | 1.02 (0.68–1.52) | 0.84 (0.56–1.27) | 0.81 (0.53–1.22) |
| AA | 9/41 | 0.42 ± 0.84 | 2.03 (0.61–6.83) | 2.31 (0.61–8.77) | 2.34 (0.62–8.83) |
| Asian | 134/277 | 1.16 ± 2.14 | 0.98 (0.64–1.51) | 0.79 (0.53–1.19) | 0.82 (0.55–1.24) |
| Severe AE | |||||
| Total | 51/465 | 0.22 ± 0.68 | 1.13 (0.74–1.75) | 0.89 (0.55–1.43) | 0.87 (0.54–1.41) |
| NHW | 13/166 | 0.14 ± 0.30 | 1.15 (0.55–2.38) | 0.97 (0.45–2.08) | 0.92 (0.43–2.00) |
| AA | 5/37 | 0.24 ± 0.50 | 2.04 (0.35–12.0) | 1.08 (0.16–7.36) | 1.05 (0.15–7.16) |
| Asian | 33/262 | 0.20 ± 0.73 | 1.16 (0.46–2.93) | 0.68 (0.26–1.77) | 0.68 (0.26–1.78) |
*
P < 0.05.
Model 1 was adjusted for age, sex, smoking pack-years, BMI, mMRC, total CAT score, post-bronchodilator FEV1 (%predicted) at enrollment.
Model 2 was further adjusted for past exacerbation in the previous year (yes vs. no) in addition to Model 1.
IRR was calculated with reference to the non-ICS user in patients with ACO.
AA, African American; ACO, asthma–COPD overlap; AE, acute exacerbation; BMI, body mass index; CI, confidence interval; COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in1 s; ICS, inhaled corticosteroid; IRR, incident rate ratio; NHW, non-Hispanic white; OR, odds ratio; PY, pack-years; SD, standard deviation.