| Cohort | 231 patients, 83 deaths, median follow-up 24.8 months |
| Follow-up end date | Death date, or each patient's own last-contact date if censored |
| Kaplan-Meier | Product-limit estimator, Greenwood CI |
| Log-rank | Mantel-Haenszel |
| Cox model | Newton-Raphson, Breslow ties |
| Minimum data | N≥10, events≥3, else "insufficient" |
| Instability guard | Flagged "unstable" if |β|>10 or SE>5 |
| Parameters screened | 65 |
| Cross-validation | Independent Python (numpy) and JavaScript (Gauss-Jordan) engines, matched to 3-4 decimals |
| Source | viv_stats.py, build_site.py included alongside this site |