Table 1

Descriptive statistics of the CPRD and QResearch samples

CPRDQResearch
Number of general practices in the study22489
All patients with a first diagnosis of IHD during the study period (incidence rate per practice)54 217 (242)16 920 (190)
Number (%) of incident cases meeting the inclusion criteria34 925 (64.4%)13 029 (77.0%)
End of study status
 Died6725 (19.3%)2266 (17.4%)
 Alive24 292 (69.6%)9609 (73.8%)
 Left before end of study3908 (11.2%)1154 (8.9%)
Total person years of observation125 70943 460
Person years%Person years%
Age band (years)
 0–4449974.08241.9
 45–5416 50613.139239.0
 55–6430 43124.2927021.3
 65–7438 36530.513 63631.4
 75–8428 08222.311 82727.2
 85–9470735.637448.6
 ≥952550.22350.5
Women57 16945.518 53942.7
Men68 54054.524 92057.3
No diabetes114 94991.439 81491.6
Diabetes10 7608.636468.4
No hypertension80 57464.130 91271.1
Hypertension45 13635.912 54728.9
No congestive cardiac failure118 20994.037 39186.0
Congestive cardiac failure75016.0606914.0
  • CPRD, Clinical Practice Research Datalink; IHD, ischaemic heart disease.