Table 1.
Strokes ascertained in Oxford Vascular Study that were not identified by hospital diagnostic coding. Figures are numbers (percentage) of patients
| All strokes (n=2373) | All incident strokes (n=1849) | ||||||
|---|---|---|---|---|---|---|---|
| Weekday | Weekend | Total | Weekday | Weekend | Total | ||
| All strokes | |||||||
| No of patients | 1745 | 628 | 2373 | 1349 | 500 | 1849 | |
| Patients not admitted | 619 (35.5) | 207 (33.0) | 826 (34.8) | 471 (34.9) | 157 (31.4) | 628 (34.0) | |
| Strokes that happened during admission for other events | 153 (8.8) | 42 (6.7) | 195 (8.2) | 93 (6.9) | 30 (6.0) | 123 (6.7) | |
| Strokes that happened out of area or abroad | 38 (2.2) | 22 (3.5) | 60 (2.5) | 37 (2.7) | 23 (4.6) | 60 (3.3) | |
| Patients admitted to hospital | 935 (53.6) | 357 (56.8) | 1292 (54.4) | 748 (55.4) | 290 (58.0) | 1038 (56.1) | |
| Strokes in patients admitted to hospital | |||||||
| No of patients | 941 | 351 | 1292 | 748 | 290 | 1038 | |
| Identified by coding from primary diagnosis | 714 (75.9) | 259 (73.8) | 973 (75.3) | 565 (75.5) | 217 (74.8) | 782 (75.3) | |
| Missed by coding | 227 (24.1) | 92 (26.2) | 319 (24.7) | 183 (24.5) | 73 (25.2) | 256 (24.7) | |
| Identified by coding but not from primary diagnosis | 3 (0.3) | 3 (0.8) | 6 (0.5) | 2 (0.3) | 3 (1.0) | 5 (0.5) | |
| Missed by coding‡ | 154 (16.4) | 59 (16.8) | 213 (16.5) | 120 (16.0) | 44 (15.2) | 164 (15.8) | |
| Inaccurately coded as transient ischaemic attack | 44 (4.6) | 21 (5.9) | 65 (5.0) | 35 (4.7) | 18 (6.2) | 53 (5.1) | |
| Inaccurately coded with other diagnosis§ | 23 (2.4) | 8 (2.3) | 31 (2.4) | 23 (3.1) | 7 (2.4) | 30 (2.9) | |
| Coding as admitted but was admitted only for investigation or early recurrence | 3 (0.3) | 1 (0.3) | 4 (0.3) | 3 (0.4) | 1 (0.3) | 4 (0.4) | |
*Based on day of week for onset.
†Based on day of week of admission.
‡True acute stroke admissions to hospital that were not matched to any administration data records obtained from same hospital.
§Such as subdural haemorrhage, occlusion of cerebral artery, cerebral aneurysm without rupture, myocardial infarction, dementia, collapse, brain injury, dysphagia.