Reliability (homogeneity)
| Subscales and items | Corrected item–total correlations for subscale items | Cronbach's α: if item deleted from six-item subscale | Mean/SD (range 5–30 (five-item response categories×six items per subscale: range of subscale: 6–30)) | % floor (positive end scores) | % ceiling (negative end scores) | Skewness (skewness: symmetry of distribution normal=0) |
| Medication subscale | Subscale: 0.715 | Subscale: 14.853/3.461 | 0.632 | |||
| 4. “The side effects of medication are worse than those from angioplasty” | 0.408 | 0.688 | 3.33/0.820 | 8 | 3 | 0.157 |
| 8. “Having to carry medication when outside the home would be troublesome” | 0.440 | 0.679 | 3.79/0.938 | 18 | 2 | 0.981 |
| 16. “With medication, the side effects are often worse than the condition” | 0.536 | 0.649 | 2.50/0.909 | 11 | 2 | 0.415 |
| 37. “Organising regular prescriptions with any medication can be a nuisance” | 0.447 | 0.678 | 3.64/0.998 | 13 | 4 | 0.967 |
| 44. “The side effects of medication are worse than those from surgery” | 0.448 | 0.680 | 3.37/0.712 | 4 | 1 | 0.111 |
| 48. “Most medication is very difficult to understand” | 0.426 | 0.684 | 3.41/1.003 | 7 | 5 | 0.747 |
| Angiography subscale | Subscale: 0.769 | Subscale: 15.961/3.578 | −0.220 | |||
| 25. “Overall, angioplasty is a good thing” | 0.558 | 0.730 | 2.29/0.694 | 12 | <1 | −0.103 |
| 28. “The balance of risks and benefits of angioplasty seem better than the risks and benefits of medication” | 0.474 | 0.744 | 2.79/0.818 | 6 | 1 | −0.124 |
| 32. “People who have angioplasty seem to do well” | 0.509 | 0.743 | 2.44/0.617 | 6 | <1 | −0.546 |
| 39. “Angioplasty is a last resort” | 0.413 | 0.767 | 2.91/1.048 | 6 | 9 | −0.100 |
| 45. “I'm too old to have angioplasty” | 0.578 | 0.718 | 3.32/1.081 | 13 | 7 | −0.349 |
| 52. “I'd put off having angioplasty” | 0.636 | 0.699 | 3.30/0.970 | 9 | 3 | −0.196 |
| Surgery (CABG) subscale | Subscale: 0.774 | Subscale: 15.121/3.357 | −0.298 | |||
| 2. “Surgery would prolong my life” | 0.534 | 0.737 | 2.61/0.903 | 13 | 2 | −0.100 |
| 30. “Overall surgery is a good thing” | 0.630 | 0.713 | 2.48/0.811 | 10 | 1 | 0.188 |
| 36. “The balance of risks and benefits of surgery seem better than the risks and benefits of medication” | 0.514 | 0.712 | 2.92/0.851 | 6 | 2 | −0.230 |
| 43. “Surgery gets the treatment over with quickly” | 0.606 | 0.718 | 2.53/0.815 | 9 | 1 | 0.121 |
| 46. “I would have surgery if I could avoid being a burden on others in the long term” | 0.374 | 0.780 | 2.27/0.886 | 18 | 1 | 0.551 |
| 47. “People who have surgery seem to do well” | 0.493 | 0.749 | 2.31/0.666 | 10 | 1 | −0.278 |
CABG, coronary artery bypass graft.
Codes were reversed for negative questionnaire items throughout so positive responses=lowest and negative responses=highest scores.