Unadjusted and adjusted IRRs with 95% CIs assessing variation in utilisation of PPCI in England, 2003–2013
| Unadjusted | Adjusted | |||
|---|---|---|---|---|
| IRR (95% CI) | p Value | IRR (95% CI) | p Value | |
| Year | 1.28 (1.27 to 1.28) | <0.001 | 1.30 (1.23 to 1.36) | <0.001 |
| Age | ||||
| <55 | Ref | Ref | ||
| 55–64 | 0.97 (0.96 to 0.99) | <0.001 | 1.00 (0.98 to 1.01) | 0.731 |
| 65–79 | 0.93 (0.92 to 0.95) | <0.001 | 0.99 (0.97 to 1.01) | 0.117 |
| 80+ | 0.83 (0.81 to 0.85) | <0.001 | 0.87 (0.85 to 0.90) | <0.001 |
| Male gender | 1.06 (1.05 to 1.08) | <0.001 | 1.02 (1.00 to 1.03) | 0.044 |
| Distance to hospital in km | ||||
| <6 | Ref | Ref | ||
| 6–15 | 1.15 (1.13 to 1.18) | <0.001 | 1.02 (0.99 to 1.04) | 0.078 |
| 16–29 | 1.32 (1.28 to 1.35) | <0.001 | 1.03 (1.00 to 1.05) | 0.025 |
| 30+ | 1.28 (1.25 to 1.32) | <0.001 | 0.95 (0.93 to 0.98) | 0.001 |
| Family history of chronic heart disease | 1.21 (1.19 to 1.23) | <0.001 | 1.01 (1.00 to 1.03) | 0.085 |
| Previous acute MI | 0.92 (0.90 to 0.94) | <0.001 | 0.95 (0.93 to 0.98) | <0.001 |
| Previous chronic cardiac failure | 0.76 (0.72 to 0.81) | <0.001 | 0.86 (0.81 to 0.92) | <0.001 |
| Previous angina | 0.86 (0.84 to 0.88) | <0.001 | 0.96 (0.94 to 0.98) | 0.001 |
| Diabetes mellitus | 1.00 (0.98 to 1.02) | 0.860 | 0.97 (0.95 to 0.99) | 0.001 |
| Chronic renal failure | 0.90 (0.86 to 0.95) | <0.001 | 0.89 (0.85 to 0.94) | <0.001 |
| Previous PCI | 1.11 (1.09 to 1.14) | <0.001 | 1.09 (1.05 to 1.12) | <0.001 |
| Previous CABG | 0.93 (0.89 to 0.97) | <0.001 | 0.96 (0.92 to 1.01) | 0.130 |
| Cerebrovascular disease | 0.94 (0.91 to 0.97) | <0.001 | 0.96 (0.93 to 0.99) | 0.012 |
| Smoker | 1.04 (1.03 to 1.06) | <0.001 | 1.01 (0.99 to 1.02) | 0.205 |
| Total number of beds at trust | ||||
| <700 | Ref | Ref | ||
| 700–999 | 0.93 (0.89 to 0.98) | 0.003 | 0.99 (0.95 to 1.04) | 0.802 |
| 1000+ | 0.75 (0.71 to 0.79) | <0.001 | 0.92 (0.88 to 0.97) | 0.001 |
| Number of interventional cardiologists | ||||
| <5 | Ref | Ref | ||
| >5 | 4.10 (4.00 to 4.21) | <0.001 | 1.30 (1.25 to 1.34) | <0.001 |
| Number of visiting interventional cardiologists | ||||
| 0 | Ref | Ref | ||
| 1–5 | 3.46 (3.37 to 3.56) | <0.001 | 1.31 (1.26 to 1.36) | <0.001 |
| 6+ | 4.22 (4.09 to 437) | <0.001 | 1.42 (1.35 to 1.49) | <0.001 |
| PPCI service | ||||
| Daytime only (09:00–17:00) | Ref | Ref | ||
| 24 h service 7 days a week | 7.19 (6.99 to 7.39) | <0.001 | 2.69 (2.58 to 2.81) | <0.001 |
| Teaching status (university hospital) | 1.27 (1.19 to 1.36) | <0.001 | 1.01 (0.93 to 1.10) | 0.809 |
CABG, coronary artery bypass graft surgery; IMD, index of multiple deprivation; IRR, incidence rate ratio; MI, myocardial infarction; PCI, percutaneous coronary intervention; PPCI, primary PCI.