Crude and adjusted relative risk (RR) estimates and 95% confidence intervals (CI) of asthma death by number of prescriptions (Rx) for respiratory drugs in the previous year
| Cases (n=43) | Controls (n=860) | Crude RR (95% CI) | Adjusted RR (95% CI)* | |
|---|---|---|---|---|
| *Adjusted for age, sex, BMI, smoking, prior hospital admissions for asthma, prior specialist visits, frequency of visits to the GP, and all the drug variables shown in the table. | ||||
| Short acting β agonists | ||||
| <3 Rx | 2 | 443 | Reference | Reference |
| 3–6 Rx | 2 | 188 | 2.4 (0.3 to 16.9) | 3.4 (0.4 to 29.1) |
| 7–12 Rx | 11 | 157 | 15.5 (3.4 to 70.8) | 16.2 (2.6 to 101.3) |
| 13+ Rx | 28 | 72 | 86.1 (20.1 to 369.5) | 51.6 (7.9 to 344.6) |
| Long acting β agonists | ||||
| Non-use | 31 | 798 | Reference | Reference |
| 1–6 Rx | 6 | 44 | 3.5 (1.4 to 8.9) | 0.8 (0.2 to 3.3) |
| 7+ Rx | 6 | 18 | 8.6 (3.2 to 23.1) | 3.2 (0.7 to 14.1) |
| Antimuscarinics | ||||
| Non-use | 16 | 765 | Reference | Reference |
| 1–6 Rx | 7 | 51 | 6.6 (2.6 to 16.7) | 2.3 (0.6 to 8.2) |
| 7+ Rx | 20 | 44 | 21.7 (10.5 to 44.8) | 3.2 (1.1 to 9.7) |
| Inhaled steroids | ||||
| Non-use | 6 | 346 | Reference | Reference |
| 1–6 Rx | 15 | 340 | 2.5 (1.0 to 6.6) | 0.7 (0.2 to 2.9) |
| 7+ Rx | 22 | 174 | 7.3 (2.9 to 18.3) | 0.7 (0.2 to 2.8) |
| Oral steroids | ||||
| Non-use | 15 | 693 | Reference | Reference |
| 1–6 Rx | 11 | 18 | 3.4 (1.5 to 7.6) | 1.4 (0.5 to 4.3) |
| 7+ Rx | 17 | 19 | 41.3 (18.0 to 94.9) | 10.1 (2.8 to 37.0) |
| Theophyllines | ||||
| Non-use | 25 | 773 | Reference | Reference |
| 1–6 Rx | 8 | 42 | 5.9 (2.5 to 13.8) | 1.7 (0.5 to 6.6) |
| 7+ Rx | 10 | 45 | 6.9 (3.1 to 15.2) | 1.2 (0.4 to 3.8) |
| Cromoglycates | ||||
| Non-use | 41 | 844 | Reference | Reference |
| 1+ Rx | 2 | 16 | 2.6 (0.6 to 11.6) | 0.5 (0.1 to 5.1) |