Attributes and levels
| Attributes | Description | Levels* | Expected sign |
| Breast cancer | |||
| 1) Volume | Total number of treated patients diagnosed with breast cancer | 100, 350 and 450 patients | + |
| 2) Waiting time 1 | Average waiting time between diagnosis and tumour resection | 15 days and 25 days | – |
| 3) Waiting time 2 | Average waiting time between diagnosis and combination surgery | 25 days and 45 days | + |
| 4) Preserved breast contour | Share of patients with a tumour resection whose breast contour was preserved | 60%, 80% and 90% | + |
| 5) Combination surgery† | Share of patients with a tumour resection who received a combination surgery | 10%, 30% and 60% | + |
| 6) Tumour residual‡ | Share of tumour resections for which the tumour resection margin was shown to be irradical | 1% and 5% | – |
| Colon cancer | |||
| 1) Volume | Total number of treated patients diagnosed with colon cancer | 50, 150 and 200 patients | + |
| 2) Waiting time | Share of patients whose waiting time between diagnosis and tumour resection amounted to less than 5 weeks | 60%, 80% and 90% | + |
| 3) Tumour residual§ | Share of tumour resections for which the tumour resection margin was shown to be radical | 85% and 95% | + |
| 4) Complications¶ | Share of patients with a tumour resection for which surgery-related complications occurred (risk-adjusted) | 10% and 20% | – |
| 5) Failure to rescue** †† | Share of patients with a tumour resection for which failure to rescue occurred (risk-adjusted) | 5% and 15% | – |
*Across all attributes, the lowest level was used as reference level.
†Type of surgery in which tumour resection and breast contour reconstruction are performed within a single operating session.
‡Resections are classified as irradical when tumour cells have been observed in the circumferential resection margin. Non-tumour-free margins are associated with unfavourable outcomes such as higher tumour recurrence rates.31
§In radical resections, contrary to irradical resections, no tumour cells have been observed in the circumferential resection margin and are associated with favourable outcomes (ie, disease-free survival).32
¶Adjusted for gender, body mass index, age, Charlson Comorbidity Score, American Society of Anaesthesiologists (ASA) classification, preoperative tumour complications, tumour location, extent of resection due to invasive tumour growth or metastases, pT stadium (ie, primary tumour site) and pM stadium (ie, presence of distant metastasis) of the TNM-classification of malignant tumours.33
**The share of patients with surgery-related complications who died while in hospital or within 30 days following surgery.12 Relative to hospitals with high failure to rescue rates, those with low rates are considered to be more successful in saving a patient’s life when surgery-related complications have occurred.34
††Adjusted for all the listed case-mix variables under ¶, and for the urgency of the resection (acute or elective).