| |
ICS cohorts (n=26,834) |
ICS/LABA cohorts (n=20,814) |
| Characteristic |
Switch to QD
(n=941) |
Remain on BD
(n=25,893) |
p value* |
Switch to QD
(n=505) |
Remain on BD
(n=20,309) |
p value* |
| Female sex, n (%) |
498 (52.9) |
14,250 (55.0) |
0.201 |
327 (64.8) |
12,353 (60.8) |
0.074 |
| Age at index date, median (IQR) |
32 (12-49) |
26 (10-47) |
<0.001 |
44 (24-56) |
42 (24-55) |
0.560 |
| 4-11 years, n (%) |
226 (24.0) |
7994 (30.9) |
<0.001 |
55 (10.9) |
2155 (10.6) |
0.380 |
| 12-60 years, n (%) |
636 (67.6) |
16,018 (61.9) |
|
373 (73.9) |
15,472 (76.2) |
|
| 61-80 years (all nonsmokers), n (%) |
79 (8.4) |
1881 (7.3) |
|
77 (15.2) |
2682 (13.2) |
|
| BMI (kg/m2), mean (SD)† |
25.2 (6.4) |
25.1 (7.3) |
0.164 |
26.8 (6.7) |
27.1 (6.8) |
0.238 |
| Underweight (BMI <18.5 kg/m2), n (%) |
101 (14.4) |
3242 (17.5) |
0.193 |
37 (8.5) |
1316 (7.5) |
0.719 |
| Normal BMI (18.5-24.49 kg/m2), n (%) |
257 (36.6) |
6620 (35.7) |
|
151 (34.6) |
5843 (33.1) |
|
| Overweight (BMI 25-29.99 kg/m2), n (%) |
200 (28.5) |
4955 (26.7) |
|
130 (29.7) |
5553 (31.5) |
|
| Obese (BMI ≥30 kg/m2), n (%) |
144 (20.5) |
3734 (20.1) |
|
119 (27.2) |
4942 (28.0) |
|
| Recorded smoking status, n (%) |
877 (93.2) |
23,674 (91.4) |
|
484 (95.8) |
19,721 (97.1) |
|
| Current smoker |
181 (20.6) |
5965 (25.2) |
0.007 |
103 (21.3) |
3970 (20.1) |
0.822 |
| Ex-smoker |
226 (25.8) |
5496 (23.2) |
|
97 (20.0) |
4029 (20.4) |
|
| Non-smoker |
470 (53.6) |
12,213 (51.6) |
|
284 (58.7) |
11,722 (59.4) |
|
| Socioeconomic status, median (IQR)‡ |
17.7 (8.4-41) |
17.9 (9.4-33.9) |
0.438 |
23.4 (11.2-42.0) |
17.9 (8.8-33.0) |
0.004 |
| Recorded comorbidity/treatment, n (%)§ |
|
|
|
|
|
|
| Rhinitis |
303 (32.2) |
8057 (31.1) |
0.481 |
170 (33.7) |
6802 (33.5) |
0.936 |
| Cardiac disease |
187 (19.9) |
4713 (18.2) |
0.193 |
141 (27.9) |
5612 (27.6) |
0.886 |
| Gastroesophageal reflux disease |
140 (14.9) |
3213 (12.4) |
0.024 |
118 (23.4) |
4690 (23.1) |
0.886 |
| ≥ 1 prescription prior 12 months (%) |
|
|
|
|
|
|
| NSAID |
138 (14.7) |
3677 (14.2) |
0.689 |
119 (23.6) |
4244 (20.9) |
0.146 |
| Beta blocker |
16 (1.7) |
500 (1.9) |
0.613 |
3 (0.6) |
343 (1.7) |
0.057 |
| Acetaminophen |
157 (16.7) |
5108 (19.7) |
0.021 |
137 (27.1) |
5051 (24.9) |
0.247 |
| Daily ICS dose (μg/d), median (IQR)ǁ |
164 (99-329) |
219 (110-384) |
<0.001 |
329 (164-756) |
395 (164-822) |
0.009 |
| Mean daily ICS dose, n (%) |
|
|
|
|
|
|
| 1-100 μg/d |
245 (26) |
5216 (20.1) |
<0.001 |
81 (16.0) |
2246 (11.1) |
0.010 |
| 101-200 μg/d |
275 (29.2) |
7594 (29.3) |
|
89 (17.6) |
3597 (17.7) |
|
| 201-400 μg/d |
231 (24.5) |
6743 (26.0) |
|
108 (21.4) |
4352 (21.4) |
|
| 401-800 μg/d |
134 (14.2) |
4361 (16.8) |
|
109 (21.6) |
4955 (24.4) |
|
| ≥ 801 μg/d |
56 (6.0) |
1979 (7.6) |
|
118 (23.4) |
5159 (25.4) |
|
| Concomitant LTRA, n (%) |
26 (2.8) |
287 (1.1) |
<0.001 |
78 (15.4) |
1946 (9.6) |
<0.001 |
| No. SABA scripts, median (IQR) |
2 (1-4) |
2 (1-4) |
<0.001 |
3 (1-5) |
3 (1-7) |
<0.001 |
| Mean daily SABA dose, n (%)ǁ |
|
|
|
|
|
|
| 0-100 μg/d |
335 (35.6) |
7764 (30.0) |
<0.001 |
134 (26.5) |
4386 (21.6) |
<0.001 |
| 101-200 μg/d |
260 (27.6) |
7032 (27.2) |
|
121 (24.0) |
4022 (19.8) |
|
| 201-400 μg/d |
188 (20) |
5844 (22.6) |
|
131 (25.9) |
4980 (24.5) |
|
| ≥401 μg/d |
158 (16.8) |
5253 (20.3) |
|
119 (23.6) |
6921 (34.1) |
|
| No loss of asthma control, n (%)¶ |
685 (72.8) |
17,330 (66.9) |
<0.001 |
298 (59.0) |
11,040 (54.4) |
0.038 |
| No loss of asthma control + limited SABA, n (%)¶ |
442 (47.0) |
10,354 (40.0) |
<0.001 |
174 (34.5) |
5181 (25.5) |
<0.001 |
| Total exacerbations, n (%)¶ |
|
|
|
|
|
|
| 0 |
690 (73.3) |
17,452 (67.4) |
<0.001 |
303 (60.0) |
11,135 (54.8) |
0.054 |
| 1 |
177 (18.8) |
5263 (20.3) |
|
102 (20.2) |
4385 (21.6) |
|
| ≥ 2 |
74 (7.9) |
3178 (12.3) |
|
100 (19.8) |
4789 (23.6) |
|
| Primary care consultations, n (%) |
|
|
|
|
|
|
| 0-3 |
259 (27.5) |
6747 (26.1) |
0.226 |
73 (14.5) |
3249 (16.0) |
0.494 |
| 4-5 |
167 (17.7) |
4574 (17.7) |
|
78 (15.4) |
2743 (13.5) |
|
| 6-8 |
220 (23.4) |
5625 (21.7) |
|
101 (20.0) |
4060 (20.0) |
|
| 9-13 |
166 (17.6) |
5315 (20.5) |
|
110 (21.8) |
4829 (23.8) |
|
| ≥14 |
129 (13.7) |
3632 (14.0) |
|
143 (28.3) |
5428 (26.7) |
|
*The Mann-Whitney U test was used to compare continuous variables and the χ2 test, categorical variables.
†Weight and height to calculate BMI were available for 702 (74.6%) and 18,529 (71.6%) of patients in ICS QD and BD cohorts, respectively, and 437 (86.5%) and 17,651 (86.9%) of patients in ICS/LABA QD and BD cohorts, respectively.
‡The socioeconomic status is the Index of Multiple Deprivation score linked to each practice postcode.
§Patients with rhinitis, cardiac disease, and GERD included those with a recorded diagnosis or recorded therapy for same.
ǁThe ICS dose is the beclomethasone dipropionate-equivalent, and the SABA dose is the albuterol equivalent.
¶Composite database measure (defined in text).
BD: Twice Daily; BMI: Body Mass Index; ICS: Inhaled Corticosteroid; IQR: Interquartile Range; LABA: Long-Acting Β-Agonist; LTRA: Leukotriene Receptor Antagonist;
NSAID: Non-steroidal Anti-Inflammatory Drug; QD: Once Daily; SABA: Short-Acting β-Agonist |
