Total number of patients and exacerbation rate over time (mean rates for each period given, weeks refer to ISO weeks)
| Exacerbation rate (number of episodes/person-year) mean (95% CI) | ||||
| Period | Number of patients in cohort | Resolved within primary care only | Required hospital visit | Overall |
| 2016 (weeks 1–12) | 100 165 | 0.82 (0.76 to 0.87) | 0.11 (0.10 to 0.11) | 0.92 (0.87 to 0.98) |
| 2016 (weeks 13–32) | 99 813 | 0.52 (0.49 to 0.55) | 0.10 (0.09 to 0.10) | 0.61 (0.58 to 0.64) |
| 2017 (weeks 1–12) | 98 264 | 0.71 (0.62 to 0.80) | 0.13 (0.12 to 0.14) | 0.84 (0.75 to 0.93) |
| 2017 (weeks 13–32) | 97 689 | 0.46 (0.43 to 0.48) | 0.10 (0.09 to 0.11) | 0.56 (0.53 to 0.58) |
| 2018 (weeks 1–12) | 96 012 | 0.73 (0.64 to 0.82) | 0.15 (0.13 to 0.16) | 0.88 (0.79 to 0.97) |
| 2018 (weeks 13–32) | 95 410 | 0.43 (0.40 to 0.45) | 0.13 (0.12 to 0.13) | 0.55 (0.53 to 0.57) |
| 2019 (weeks 1–12) | 91 439 | 0.62 (0.55 to 0.68) | 0.14 (0.13 to 0.15) | 0.75 (0.68 to 0.82) |
| 2019 (weeks 13–32) | 88 976 | 0.41 (0.38 to 0.44) | 0.10 (0.10 to 0.11) | 0.51 (0.48 to 0.54) |
| 2020 (weeks 1–12) | 77 258 | 0.63 (0.59 to 0.67) | 0.16 (0.14 to 0.17) | 0.78 (0.74 to 0.83) |
| 2020 (weeks 13–32) | 67 995 | 0.23 (0.20 to 0.25) | 0.10 (0.09 to 0.11) | 0.33 (0.30 to 0.35) |
Total number of exacerbation episodes: 278 996; exacerbation episodes managed exclusively by a general practitioner: 229 058 (82.1%); exacerbation episodes requiring hospital visit: 49 938 (17.9%).