VTE event rates according to selected participant characteristics
| Characteristics | Number of eventsa/person years | Relative risk (95% CIb) | P-value | |
|---|---|---|---|---|
| Sex | Male (reference) | 4/240 | 1 | – |
| Female | 17/608 | 1.67 (0.56 to 4.99) | 0.350 | |
| Age, years | <75 (reference) | 2/106 | 1 | – |
| 75–84 | 1/258 | 0.21 (0.02 to 2.27) | 0.200 | |
| ≥85 | 18/483 | 1.98 (0.46 to 8.51) | 0.360 | |
| Rivermead Mobility Index | 0 (reference) | 3/183 | 1 | – |
| 1–6 | 8/301 | 1.62 (0.43 to 6.11) | 0.480 | |
| 7–15 | 10/364 | 1.68 (0.46 to 6.09) | 0.430 | |
| Length of stay since admission | <1 year | 9/306 | 2.74 (0.35 to 21.59) | 0.340 |
| 1 to 5 years | 11/448 | 2.28 (0.29 to 17.69) | 0.430 | |
| >5 years (reference) | 1/93 | 1 | – | |
| Type of care home | With nursing | 17/575 | 2.02 (0.68 to 6.00) | 0.210 |
| Without nursing (reference) | 4/273 | 1 | – | |
| Previous VTE | Previous VTE | 5/76 | 3.17 (1.16 to 8.66) | 0.024 |
| No previous VTE (reference) | 16/772 | 1 | – | |
| Malignancy | Malignancy | 3/114 | 1.07 (0.32 to 3.64) | 0.910 |
| No malignancy (reference) | 18/733 | 1 | – | |
| Obesity, body mass index | >30 kg/m2 | 3/125 | 0.99 (0.29 to 3.41) | 0.990 |
| ≤30 kg/m2 (reference) | 16/663 | 1 | – | |
| Significant medical comorbiditiesc | 0 (reference) | 4/453 | 1 | – |
| ≥1 | 17/395 | 4.87 (1.64 to 14.49) | 0.004 | |