Table 3.
Description of the data per paper and per model
| EDa 4 papers 22 models |
In-hospitala 7 papers 43 models |
ICUa 15 papers 52 models |
||||
|---|---|---|---|---|---|---|
| Absolute | Proportion | Absolute | Proportion | Absolute | Proportion | |
| Per paper | ||||||
| Prospective design | 1 | 0.25 | 2 | 0.29 | 1 | 0.07 |
| Privacy statement | 0 | 0.00 | 3 | 0.43 | 5 | 0.33 |
| MIMICb | – | – | – | – | 9 | 0.60 |
| Description of patients | 4 | 1.00 | 2 | 0.29 | 5 | 0.33 |
| Inclusion criteria | 3 | 0.75 | 4 | 0.57 | 12 | 0.80 |
| Country—USA | 4 | 1.00 | 7 | 1.00 | 15 | 1.00 |
| Per model | ||||||
| Target condition | ||||||
| Sepsis | 20 | 0.91 | 10 | 0.23 | 37 | 0.71 |
| Severe sepsis | 0 | 0.00 | 1 | 0.02 | 12 | 0.23 |
| Severe sepsis & septic shock | 2 | 0.09 | 1 | 0.02 | 0 | 0.00 |
| Septic shock | 0 | 0.00 | 31 | 0.72 | 3 | 0.06 |
| Components of target condition definition | ||||||
| ICD | 20 | 0.91 | 32 | 0.74 | 17 | 0.33 |
| SIRS | 0 | 0.00 | 4 | 0.09 | 19 | 0.37 |
| SOFA | 0 | 0.00 | 1 | 0.02 | 21 | 0.40 |
| Data split design | ||||||
| Train-(validate)-test | 20 | 0.91 | 15 | 0.35 | 21 | 0.40 |
| Cross-validation | 0 | 0.00 | 25 | 0.58 | 28 | 0.54 |
| Data granularity | ||||||
| 1-hourly values | – | – | 6 | 0.14 | 30 | 0.58 |
| > 1/hourly values | – | – | 0 | 0.00 | 18 | 0.35 |
| Not described | – | – | 31 | 0.72 | 4 | 0.08 |
| Missing values strategies | ||||||
| Feedforward | 0 | 0.00 | 8 | 0.19 | 14 | 0.27 |
| Mean imputation | 0 | 0.00 | 9 | 0.21 | 12 | 0.23 |
| Zero imputation | 0 | 0.00 | 16 | 0.37 | 0 | 0.00 |
| Nearest neighbor | 0 | 0.00 | 0 | 0.00 | 16 | 0.31 |
| Physiological imputation | 13 | 0.59 | 0 | 0.00 | 0 | 0.00 |
| Otherc | 7 | 0.32 | 3 | 0.07 | 2 | 0.04 |
| Not described | 2 | 0.09 | 7 | 0.16 | 8 | 0.15 |
| Model | ||||||
| Generalized linear model | 3 | 0.14 | 6 | 0.14 | 15 | 0.29 |
| Naïve Bayes | 11 | 0.50 | 3 | 0.07 | 0 | 0.00 |
| Ensemble methods | 4 | 0.18 | 9 | 0.21 | 7 | 0.13 |
| Proportional hazard | 0 | 0.00 | 0 | 0.00 | 9 | 0.17 |
| Decision tree | 0 | 0.00 | 9 | 0.21 | 0 | 0.00 |
| Support vector machines | 4 | 0.18 | 3 | 0.07 | 11 | 0.21 |
| Neural network | 0 | 0.00 | 8 | 0.19 | 6 | 0.12 |
| Long short-term memory (LSTM) | 0 | 0.00 | 5 | 0.12 | 4 | 0.08 |
ICD International Statistical Classification of Diseases and Related Health Problems, SIRS systemic inflammatory response syndrome, SOFA sequential organ failure assessment
aStudy by Mao et al. (2017) with an ED, In-hospital, ICU setting has been omitted for brevity
bStudies that included MIMIC in at least one of their reported models
cOthers: proxy variable, removal of variable, and predictive mean matching