Table 2.
Handling of missing data
| Object | Count | Action |
|---|---|---|
| Total cases | 585 396 | Separated as below |
| Duplicate episodes | 32 829 | Excluded |
| First year attendances | 182 184 | Not part of main analysis |
| Children or unknown age | 25 954 | Not part of main analysis |
| Missing sex | 1038 | Imputed by inferring sex from name |
| Missing triage category | 74 977 | Imputed by logical rules |
| Missing NEWS in triage category 1 | 6975 | Imputed by sampling matched cases |
| Died | 560 | Counted as admissions |
| Unknown outcome | 1616 | Excluded (missing completely at random) |
| Irregular discharge | 14 151 | Excluded |
| Transfers | 5816 | Removed to avoid double counts |
GP, general practitioner; NEWS, National Early Warning Score.