Table 1 Summary of included studies in this literature review
Studies (author, year) | Study design | Participants | Sample size (outcome%) | Outcome | Prediction duration | ML algorithms (n) | Validation methods | Generalization testa | Features in the final model | Performance measure in the validation dataset | Quality (PROBAST) | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Bias | Applicability | |||||||||||
Lieu, 1999 [16] | Retrospective | Asthma | 7141 (HP 0.8%, ED 6.6%) | HP or ED for asthma | Next year | CART (1) | Split-sample validation | Y (in separate dataset) | 14 | Internal: Spe 0.836, Sen 0.49, PPV 0.185 | High | High |
Schatz, 2004 [17] | Retrospective | Asthma | 8789 (5.5%) | HP or ED for asthma | Next year | LR (1) | - | Y (geographic) | 3 | External: Spe 0.92, Sen 0.254, NPV 0.932 | High | High |
Schatz, 2006 [18] | Retrospective | Asthma | 1079 (9.5%) | HP or ED | Next year | LR (1) | - | Y (temporal) | 1 | External: Spe 0.541, Sen 0.646, NPV 0.96, PPV 0.083, AUC 0.59 | High | High |
Xu, 2011 [19] | Retrospective | Mild-moderate asthma | 417 (30%) | Severe AE | Four years | RF (1) | Cross validation | Y (in separate sample) | 164 | External: AUC 0.66, Spe 0.6, Sen 0.66, NPV 0.81, PPV 0.74 | High | High |
van Vliet, 2017 [20] | Prospective | Asthma | 574 samples (13.4%) from 94 patients (48%) | Moderate-severe AE | 0–14 days, 0–21 days | RF (2) | Bagging | - | 7 | 32 samples: 0–14 days (Spe 0.75, Sen 0.88, CCR 0.82, AUC 0.90) 48 samples: 0–21 days (Spe 0.67, Sen 0.85, CCR 0.65) | High | Low |
Luo, 2020 [15] | Retrospective | Asthma | 315,308 (3.6%) | HP or ED for asthma | Next year | XGBoost (1) | Cross validation | Y (temporal) | 142 | External: Spe 0.9193, Sen 0.5369, CCR 0.9031, AUC 0.859 | High | High |
Luo, 2020 [14] | Retrospective | Asthma | 782,762 (2.42%) | HP or ED for asthma | Next year | XGBoost (1) | - | Y (temporal) | 221 | External: Spe 0.9091, Sen 0.5190, CCR 0.9008, AUC 0.820 | High | High |
Tong, 2021 [21] | Retrospective | Asthma | 68,244 (1.7%) | HP or ED for asthma | Within 1 year | XGBoost (1) | Unclear | Y (temporal) | 71 | External: Spe 0.9091, Sen 0.7018, CCR: 0.906, AUC 0.902 | High | High |
Zein, 2021 [22] | Retrospective | Asthma | 60,302 (nonsevere AE 32.8%, ED 2.9%, HP 1.5%) | Nonsevere AE (oral steroids burst), severe AE (HP or ED for asthma) | 3 years (mean) | LR (3), RF (3), LGBM (3) | - | Y (20% of dataset, temporal) | 56 | 20% of dataset: LGBM: Nonsevere (AUC 0.71, Spe 0.67, Sen 0.64), ED (AUC 0.88, Spe 0.76, Sen 0.84), HP (AUC 0.85, Spe 0.73, Sen 0.86)) | High | High |
External: LGBM: nonsevere (AUC 0.65), ED (AUC 0.86), HP (AUC 0.87)) | ||||||||||||
Noble, 2021 [23] | Retrospective | Asthma | 58,619 (1.65%) | HP for asthma | Within one year | LR (1) | - | Y (in separate dataset) | 14 | External: AUC 0.71, Spe 0.933, Sen 0.285 | High | High |
de Hond, 2022 [24] | Retrospective | Stable, mild-moderate asthma | 92,787 daily measurements (0.2%) from 165 patients (30%) | Severe AE | 2 days | XGBoost (1), one class SVM (1), LR (1) | Cross validation | Y (in separate dataset) | Unclear | External: XGBoost (AUC 0.81, Spe 0.89, Sen 0.59), LR: (AUC 0.88, Spe 0.82, Sen 0.84), one class SVM (Spe 0.87, Sen 0.34) | High | High |