Table 4.
Cumulative revision and differences by hospital volume of procedures by year in total knee arthroplasty (TKA). RACat 2005–2016.
| Time (in Years) | At Risk | Revisions | Cum. Failure (95% CI) | SHR (95% CI) |
|---|---|---|---|---|
| Lower volume | 1.00 | |||
| 1 | 16,594 | 112 | 0.64 (0.53–0.77) | |
| 5 | 9,064 | 366 | 3.24 (2.96–3.53) | |
| 10 | 1,217 | 80 | 4.66 (4.21–5.13) | |
| Higher volume | 1.29 (1.16–1.44) | |||
| 1 | 16,293 | 202 | 1.15 (1.00–1.32) | |
| 5 | 8,673 | 422 | 4.17 (3.85–4.50) | |
| 10 | 744 | 89 | 5.84 (5.33–6.39) |
At risk: Number of primary procedures at the beginning of the period. Revisions: Number of revision procedures during the period; cum. failure: Cumulative failure; (95% CI): 95% confidence interval. SHR: Subhazard ratio for the hospital volume (Lower volume as reference category) adjusted for sex, age, comorbidity (from Elixhauser index), year of intervention and type of fixation.