Table 1.
Distribution of patient and encounter characteristics for all alerts and standardized mean difference before and after weighting
| Factor | Level | Control phase alerts (n = 15 056) |
Live phase alerts (n = 6127) |
All alerts (n = 21 183) |
Standardized mean difference (%) |
|||||
|---|---|---|---|---|---|---|---|---|---|---|
| n | % | n | % | n | % | Before IPTW | After IPTW | |||
| Age group | 18-44 y (ref) | 2588 | 17.2 | 1239 | 20.2 | 3827 | 18.1 | 13.0 | 11.5 | |
| 45-64 y | 4431 | 29.4 | 1644 | 26.8 | 6075 | 28.7 | ||||
| 65-69 y | 1594 | 10.6 | 515 | 8.4 | 2109 | 10.0 | ||||
| 70-74 y | 1583 | 10.5 | 603 | 9.8 | 2186 | 10.3 | ||||
| 75-79 y | 1605 | 10.7 | 636 | 10.4 | 2241 | 10.6 | ||||
| 80-84 y | 1393 | 9.3 | 601 | 9.8 | 1994 | 9.4 | ||||
| 85 y and older | 1862 | 12.4 | 889 | 14.5 | 2751 | 13.0 | ||||
| Sex | Female | 6936 | 46.1 | 2735 | 44.6 | 9671 | 45.7 | 2.0 | 0.4 | |
| Male | 8120 | 54.0 | 3392 | 55.4 | 11512 | 54.4 | ||||
| Ethnicity | White | 6986 | 46.4 | 3063 | 50.0 | 10049 | 47.4 | 12.8 | 2.7 | |
| Black | 1667 | 11.1 | 708 | 11.6 | 2375 | 11.2 | ||||
| Not known | 2473 | 16.4 | 784 | 12.8 | 3257 | 15.4 | ||||
| Other | 2923 | 19.4 | 1257 | 20.5 | 4180 | 19.7 | ||||
| Asian | 1007 | 6.7 | 315 | 5.1 | 1322 | 6.2 | ||||
| Deprivation quintile | Least deprived | 2787 | 18.5 | 1591 | 26.0 | 4378 | 20.7 | 22.4 | 9.1 | |
| 3953 | 26.3 | 1662 | 27.1 | 5615 | 26.5 | |||||
| 4024 | 26.7 | 1468 | 24.0 | 5492 | 25.9 | |||||
| 2243 | 14.9 | 713 | 11.6 | 2956 | 14.0 | |||||
| Most deprived | 1277 | 8.5 | 319 | 5.2 | 1596 | 7.5 | ||||
| Not known | 772 | 5.1 | 374 | 6.1 | 1146 | 5.4 | ||||
| Myocardial infarction | 1755 | 11.7 | 579 | 9.5 | 2334 | 11.0 | 7.2 | 8.4 | ||
| Heart failure | 2420 | 16.1 | 858 | 14.0 | 3278 | 15.5 | 5.9 | 9.4 | ||
| Peripheral vascular disease | 1186 | 7.9 | 384 | 6.3 | 1570 | 7.4 | 6.9 | 1.2 | ||
| Stroke | 2257 | 15.0 | 909 | 14.8 | 3166 | 15.0 | 0.8 | 1.7 | ||
| Dementia | 1082 | 7.2 | 558 | 9.1 | 1640 | 7.7 | 8.0 | 1.8 | ||
| Pulmonary | 3626 | 24.1 | 1928 | 31.5 | 5554 | 26.2 | 16.0 | 1.5 | ||
| Rheumatic | 567 | 3.8 | 225 | 3.7 | 792 | 3.7 | 0.3 | 4.0 | ||
| Peptic ulcer disease | 215 | 1.4 | 109 | 1.8 | 324 | 1.5 | 1.8 | 7.3 | ||
| Liver disease–mild | 957 | 6.4 | 426 | 7.0 | 1383 | 6.5 | 2.0 | 0.6 | ||
| Diabetes–uncomplicated | 3700 | 24.6 | 1478 | 24.1 | 5178 | 24.4 | 1.1 | 4.6 | ||
| Diabetes–complicated | 1145 | 7.6 | 340 | 5.6 | 1485 | 7.0 | 8.8 | 11.3 | ||
| Paralysis | 649 | 4.3 | 243 | 4.0 | 892 | 4.2 | 1.9 | 4.8 | ||
| Renal | 3141 | 20.9 | 801 | 13.1 | 3942 | 18.6 | 21.6 | 14.2 | ||
| Liver disease–severe | 328 | 2.2 | 160 | 2.6 | 488 | 2.3 | 1.9 | 0.6 | ||
| Metastatic cancer | 1329 | 8.8 | 348 | 5.7 | 1677 | 7.9 | 10.6 | 1.2 | ||
| Human immunodeficiency virus | 150 | 1.0 | 64 | 1.0 | 214 | 1.0 | 0.5 | 3.1 | ||
| Trust site | A | 6342 | 42.1 | 2427 | 39.6 | 8769 | 41.4 | 48.3 | 11.5 | |
| B | 4684 | 31.1 | 872 | 14.2 | 5556 | 26.2 | ||||
| C | 4030 | 26.8 | 2828 | 46.2 | 6858 | 32.4 | ||||
| Season of admission | Spring | 2359 | 15.7 | 2173 | 35.5 | 4532 | 21.4 | 58.8 | 6.0 | |
| Summer | 2608 | 17.3 | 394 | 6.4 | 3002 | 14.2 | ||||
| Autumn | 5553 | 36.9 | 1380 | 22.5 | 6933 | 32.7 | ||||
| Winter | 4536 | 30.1 | 2180 | 35.6 | 6716 | 31.7 | ||||
| Severity | Suspected sepsis (ref) | 8025 | 53.3 | 2775 | 45.3 | 10800 | 51.0 | 10.3 | 3.1 | |
| Suspected severe sepsis | 7031 | 46.7 | 3352 | 54.7 | 10383 | 49.0 | ||||
| NEWS score | Zero (ref) | 617 | 4.1 | 183 | 3.0 | 800 | 3.8 | 23.3 | 17.7 | |
| Low | 8513 | 56.5 | 2887 | 47.1 | 11400 | 53.8 | ||||
| Medium | 2331 | 15.5 | 1165 | 19.0 | 3496 | 16.5 | ||||
| High | 2277 | 15.1 | 1208 | 19.7 | 3485 | 16.5 | ||||
| Missing | 1318 | 8.8 | 684 | 11.2 | 2002 | 9.5 | ||||
IPTW: inverse probability of treatment weighting;NEWS: National Early Warning Score.