Table 3.
Marginal results for each variable in our final model, with all other variables held at their medians
| Predictor | Value | Marginal rate | 95% CI |
| MICA estimate>1% | 0 | 0.6% | 0.6 to 0.7 |
| 1 | 7.1% | 6.7 to 7.5 | |
| RCRI (documented) | 0 | 2.2% | 2.0 to 2.3 |
| 1 | 2.7% | 2.5 to 2.9 | |
| 2 | 3.4% | 3.0 to 3.8 | |
| 3 | 4.2% | 3.5 to 5.0 | |
| 4 | 5.1% | 4.0 to 6.5 | |
| 5 | 6.4% | 4.7 to 8.6 | |
| Subjective assessment of patient function | 1 | 2.1% | 1.9 to 2.2 |
| 2 | 2.4% | 2.2 to 2.5 | |
| 3 | 2.8% | 2.6 to 3.0 | |
| 4 | 3.2% | 2.9 to 3.5 | |
| Estimated METs | 2 | 3.3% | 2.9 to 3.7 |
| 4 | 2.7% | 2.5 to 2.9 | |
| 8 | 1.8% | 1.6 to 1.9 | |
| Body mass index | 20 | 2.1% | 1.9 to 2.3 |
| 30 | 2.4% | 2.2 to 2.5 | |
| 40 | 2.7% | 2.5 to 2.9 | |
| Diastolic blood pressure | 70 | 2.3% | 2.2 to 2.5 |
| 90 | 2.5% | 2.3 to 2.7 | |
| 110 | 2.7% | 2.4 to 3.0 | |
| Ischaemic heart disease | No | 2.1% | 2.0 to 2.3 |
| Yes | 3.6% | 3.3 to 3.9 | |
| Congestive heart failure | No | 2.4% | 2.2 to 2.5 |
| Yes | 2.1% | 1.9 to 2.3 | |
| Area deprivation index | 10 | 2.8% | 2.5 to 3.1 |
| 50 | 2.2% | 2.0 to 2.3 | |
| 90 | 2.6% | 2.4 to 2.8 | |
| Predicted probability of obstructive CAD | 5% | 2.6% | 2.4 to 2.7 |
| 10% | 2.4% | 2.3 to 2.6 | |
| 20% | 2.2% | 2.1 to 2.4 | |
| Tobacco use | Current smoker | 2.6% | 2.3 to 2.8 |
| Former smoker | 2.5% | 2.3 to 2.7 | |
| Neither | 2.2% | 2.1 to 2.4 | |
| Date | 30 June 2008 | 3.5% | 3.2 to 3.8 |
| 30 June 2013 | 2.6% | 2.4 to 2.8 | |
| 30 June 2018 | 1.3% | 1.2 to 1.4 | |
| Surgical category | Aortic | 23.4% | 6.0 to 91.1 |
| Peripheral vascular | 8.7% | 6.7 to 11.3 | |
| Urologic | 9.2% | 8.3 to 10.2 | |
| Other | 1.9% | 1.7 to 2.0 | |
| Physician (summary) | Lowest | 1.0% | 0.1 to 4.4 |
| 5th percentile | 1.2% | 0.6 to 2.6 | |
| Median | 2.3% | 2.1 to 2.6 | |
| 95th percentile | 3.8% | 3.2 to 4.5 | |
| Highest | 6.1% | 2.7 to 13.5 |
For example, with all other variables at their respective medians, a visit on 30 June 2008 would have resulted in preoperative stress testing approximately 3.5% of the time, while a visit on 30 June 2018 would have resulted in preoperative stress testing approximately 1.3% of the time. Provider effects are summarised for space considerations; full marginal results by physician are included in the online supplemental appendix.
CAD, coronary artery disease; MET, estimated metabolic equivalent; MICA, myocardial infarction or cardiac arrest calculator; RCRI, revised cardiac risk index.