Incidence of future diagnosis of COPD, asthma, or IHD in exposeda and unexposedb matched cohorts
| Time period | Exposed cohort, n= 75 698 | Unexposed matched cohort, n = 75 698 | Exposed versus adjustedd unexposed, HR (95% CI) | ||||
|---|---|---|---|---|---|---|---|
| Patients with diagnosis, n (%)c | Time at risk, person-years | Incidence per 10 000 person-years | Patients with diagnosis, n (%)c | Time at risk, person-years | Incidence per 10 000 person-years | ||
| COPD | |||||||
| Diagnostic window (0–6 months) | 2970 (3.9) | 35 349.8 | 840.2 | 72 (0.1) | 37 188.2 | 19.4 | — |
| Long-term follow-up (>6 months) | 6141 (8.1) | 441 810.8 | 139.0 | 1883 (2.5) | 503 290.6 | 37.4 | — |
| >6–12 months | 685 (0.9) | 33 467.6 | 204.7 | 80 (0.1) | 36 235.7 | 22.1 | 8.6 (6.8 to 11.0) |
| >12–36 months | 1835 (2.4) | 120 124.0 | 152.8 | 364 (0.5) | 133 356.3 | 27.3 | 5.3 (4.7 to 6.0) |
| >36 months | 3621 (4.8) | 288 219.2 | 125.6 | 1439 (1.9) | 333 698.6 | 43.1 | 2.8 (2.6 to 3.0) |
| Asthma | |||||||
| Diagnostic window (0–6 months) | 4430 (5.9) | 34 759.7 | 1274.5 | 80 (0.1) | 37 184.6 | 21.5 | — |
| Long-term follow-up (>6 months) | 6925 (9.1) | 411 223.4 | 168.4 | 1347 (1.8) | 502 628.2 | 26.8 | — |
| >6–12 months | 1032 (1.4) | 32 539.8 | 317.2 | 89 (0.1) | 36 226.2 | 24.6 | 11.7 (9.4 to 14.6) |
| >12–36 months | 2335 (3.1) | 115 176.6 | 202.7 | 347 (0.5) | 133 251.3 | 26.0 | 6.8 (6.0 to 7.6) |
| >36 months | 3558 (4.7) | 263 507.0 | 135.0 | 911 (1.2) | 333 150.7 | 27.3 | 4.3 (3.9 to 4.6) |
| IHD | |||||||
| Diagnostic window (0–6 months) | 4430 (5.9) | 34 964.4 | 1267.0 | 338 (0.4) | 37 131.6 | 91.0 | — |
| Long-term follow-up (>6 months) | 8680 (11.5) | 427 498.9 | 203.0 | 5240 (6.9) | 489 700.3 | 107.0 | — |
| >6–12 months | 1115 (1.5) | 32 864.5 | 339.3 | 386 (0.5) | 36 068.3 | 107.0 | 3.0 (2.7 to 3.4) |
| >12–36 months | 2562 (3.4) | 117 374.1 | 218.3 | 1390 (1.8) | 131 714.2 | 105.5 | 1.9 (1.8 to 2.1) |
| >36 months | 5003 (6.6) | 277 260.3 | 180.4 | 3464 (4.6) | 321 917.8 | 107.6 | 1.6 (1.5 to 1.7) |
↵a Patients with recorded breathlessness.
↵b Patients without recorded breathlessness.
↵c Percentage of total number of patients in exposed/unexposed matched cohort.
↵d Adjusted HR, adjusted for index year; age; sex; region; smoker, ever; alcohol drinker, ever; BMI; deprivation level; comorbidity; cough and sputum; inflammatory conditions; depression and anxiety; diabetes; non-specific chest pain; musculoskeletal pain. BMI = body mass index. COPD = chronic obstructive pulmonary disease. HR = hazard ratio. IHD = ischaemic heart disease.