Table 1

Baseline characteristics of consenting and non-consenting patients (for whom data were available)

Consenting patients (n=1649)Non-consenting patients (n=705)SMD*
Age (mean, SD)†64 (12.7)65.0 (14.2)0.06
Male sex1159/1516 (76%)481/677 (71%)0.12
Current smoker)478/1473 (32%)240/602 (40%)0.16
IMD score (median; IQR)‡13.4 (7.7–25.8)19.9 (10.4–34.9)0.31
WIMD rank (median; IQR) §891 (459–1370)671 (268–1221)0.27
Diabetes231/1536 (15%)134/645 (21%)0.15
Hypertension601/1455 (41%)263/663 (40%)0.03
Previous PCI157/1552 (10%)73/652 (11%)0.04
Previous CABG37/1540 (2%)25/654 (4%)0.09
Previous MI193/1547 (12%)101/650 (16%)0.09
PPCI1307/1452 (90%)429/664 (65%)0.70
No PPCI145/1452 (10%)235/664 (35%)0.70
Length of stay (median; IQR) days¶3 (2–4)2 (1–3.9)0.13
  • Values are numbers (percentages) unless otherwise stated.

  • *SMDs can be interpreted as follows: values of 0.20 are ‘small’ in magnitude, those around 0.50 are ‘medium’ and those around or above 0.80 are ‘large’.27

  • Missing data (consented patients, non-consented patients): †(8, 5), ‡(179, 15), §(92, 47), ¶(250, 78).

  • CABG, coronary artery bypass grafting; IMD, Index of Multiple Deprivation (low value reflects low level of multiple deprivation); MI, myocardial infarction; PCI, percutaneous coronary intervention; PPCI,  primary percutaneous coronary intervention; SMD, standardised mean difference; WIMD, Welsh Index of Multiple Deprivation (low value reflects high level of multiple deprivation).