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. 2020 Feb 11;70(693):e264–e273. doi: 10.3399/bjgp20X708221

Table 2.

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.