Table 3.
Metrics describing the performance of the best-performing machine learning and control algorithms of the included studies.
| Stud, year | Procedure | Outcome | Training size | Validation size | Testing size | Best control algorithm | Control metric, value | Best ML algorithm | ML metric, value |
|---|---|---|---|---|---|---|---|---|---|
| Navarro et al., 2018 | TKA | LOS | 106,085 | - | 35,361 | - | - | Bayesian | AUC, 0.78 |
| Ramkumar et al., 2019 | TKA | LOS | 150,074 | 16,675 | 4017 | - | - | ANN | AUC, 0.83 |
| Ramkumar et al., 2019 | THA | LOS | 68,810 | 7645 | 2771 | - | - | ANN | AUC, 0.80 |
| Ramkumar et al., 2019 | THA | LOS | 91,751 | - | 30,583 | - | - | Bayesian | AUC, 0.87 |
| Lee et al., 2019 | Both | 90-d readmission | 473 | 52 | - | Logistic regression | Accuracy, 0.93 | RUSBoost | Accuracy, 0.87 |
| Gabriel et al., 2019 | THA | LOS | 644 | 316 | - | Logistic regression | AUC, 0.75 | Ridge regression | AUC, 0.76 |
| Wei et al., 2021 | TKA | LOS | 15,069 | - | 10,046 | Logistic regression | AUC, 0.80 | ANN | AUC, 0.80 |
| Han et al., 2021 | TKA | LOS | 1038 | 260 | - | Logistic regression | AUC, 0.70 | RFC | AUC, 0.77 |
| Kugelman et al., 2021 | THA | LOS | 902 | 225 | 282 | - | - | XGBoost | AUC, 0.82 |
| Yeo et al., 2022 | TKA | DOS | 6413 | 1603 | 2005 | - | - | ANN | AUC, 0.82 |
| Klemt et al., 2022 | rTKA | LOS | 1656 | 414 | 518 | - | - | ANN | AUC, 0.87 |
| Lopez et al., 2022 | TKA | LOS | 216,960 | - | 54,420 | - | - | ANN | AUC, 0.80 |
| THA | LOS | 122,442 | - | 30,611 | - | - | ANN | AUC, 0.81 | |
| Abbas et al., 2022 | TKA | DOS | 182,000 | 57,841 | 62,459 | Linear regression | MSE, 0.99 | ANN | MSE, 0.89 |
| TKA | LOS | 182,000 | 57,841 | 62,459 | Linear regression | MSE, 0.79 | ANN | MSE, 0.69 | |
| Motesharei et al., 2022 | TKA | DOS | 708 | 177 | 176 | Linear regression | R2, 0.71 | CatBoost | R2, 0.76 |
| Zalikha et al., 2022 | TKA | LOS | 195,556 | 48,906 | 61,115 | - | - | SVM | AUC, 0.68 |
| Johannesdottir et al., 2022 | Both | LOS | 8561 | 951 | - | Logistic regression | AUC, 0.70 | RFC | AUC, 0.71 |
| Klemt et al., 2022 | TKA | 90-day readmission | 6413 | 1603 | 2005 | Logistic regression | - | ANN | AUC, 0.85 |
| Li et al., 2022 | TKA | LOS | - | - | - | Logistic regression | AUC, 0.64 | XGBoost | AUC, 0.74 |
| Kugelman et al., 2022 | TKA | LOS | 575 | 144 | 180 | - | - | XGBoost | AUC, 0.69 |
| Trunfio et al., 2022 | THA | LOS | 2012 | - | 503 | Linear regression | RMSE, 3.84 | GBDT | RMSE, 3.84 |
GBDT, gradient-boosted decision tree; rTKA, revision total hip arthroplasty; R2, coefficient of determination; RFC, random forest classifier; RMSE, root mean square error; SVM, support vector machines.