Table 1. Cumulative risks and rate ratios of recurrent subdural haematoma (SDH) according to concomitant medical diseases and other potential predictors in Danish SDH patients diagnosed 1996–2011.
| Potential predictors for recurrent SDH | No. of primary SDH | No. of recurrent SDH | Median follow-up time (days) | Cumulative 1-year recurrence risk in percent (95% CI) * | Adjusted RR ** (95% CI) | RR further adjusted for anticoagulation treatment*** (95% CI) | |||
|---|---|---|---|---|---|---|---|---|---|
| Age (years) | |||||||||
| 20–49 | 1895 | 255 | 1809 | 11.3 | (9.9–12.7) | 1 | (ref.) | 1 | (ref.) |
| 50–69 | 3383 | 511 | 1185 | 13.5 | (12.4–14.7) | 1.10 | (0.94–1.29) | 1.12 | (0.96–1.31) |
| 70- | 4880 | 789 | 662 | 15.2 | (14.2–16.2) | 1.41 | (1.21–1.65) | 1.42 | (1.22–1.67) |
| P < 0.0001 | |||||||||
| Sex | |||||||||
| Males | 6575 | 1157 | 1022 | 16.1 | (15.2–16.9) | 1.60 | (1.43–1.80) | 1.59 | (1.42–1.79) |
| Females | 3583 | 398 | 933 | 10.0 | (9.0–11.0) | 1 | (ref.) | 1 | (ref.) |
| Alcohol addiction | |||||||||
| Yes | 2017 | 336 | 952 | 13.9 | (12.4–15.4) | 1.20 | (1.04–1.37) | 1.17 | (1.02–1.34) |
| No | 8141 | 1219 | 970 | 13.9 | (13.2–14.7) | 1 | (ref.) | 1 | (ref.) |
| Chronic liver disease | |||||||||
| Yes | 396 | 75 | 536 | 16.2 | (12.5–19.8) | 1.27 | (0.98–1.62) | 1.25 | (0.97–1.59) |
| No | 9762 | 1480 | 993 | 13.8 | (13.1–14.5) | 1 | (ref.) | 1 | (ref.) |
| Coagulopathy | |||||||||
| Yes | 88 | 15 | 400 | 16.0 | (8.3–23.7) | 1.19 | (0.68–1.91) | 1.12 | (0.64–1.81) |
| No | 10070 | 1540 | 974 | 13.9 | (13.2–14.6) | 1 | (ref.) | 1 | (ref.) |
| Surgical treatment | |||||||||
| Yes | 4894 | 957 | 946 | 17.7 | (16.6–18.8) | 1.76 | (1.58–1.96) | 1.81 | (1.62–2.02) |
| No | 5264 | 598 | 984 | 10.4 | (9.6–11.2) | 1 | (ref.) | 1 | (ref.) |
| Antihypertensive treatment | |||||||||
| Yes | 3286 | 480 | 660 | 13.6 | (12.4–14.8) | 0.94 | (0.83–1.06) | 0.97 | 0.86–1.10 |
| No | 6872 | 1075 | 1207 | 14.0 | (13.2–14.9) | 1 | (ref.) | 1 | (ref.) |
| Renal insufficiency | |||||||||
| Yes | 207 | 36 | 354 | 16.5 | (11.4–21.6) | 1.19 | (0.83–1.63) | 1.12 | (0.79–1.54) |
| No | 9951 | 1519 | 986 | 13.9 | (13.2–14.5) | 1 | (ref.) | 1 | (ref.) |
| Diabetes mellitus | |||||||||
| Yes | 487 | 93 | 414 | 18.8 | (15.3–22.4) | 1.40 | (1.11–1.74) | 1.35 | (1.08–1.68) |
| No | 9671 | 1462 | 1013 | 13.7 | (13.0–14.4) | 1 | (ref.) | 1 | (ref.) |
| Previous cerebral ischemic infarction | |||||||||
| Yes | 773 | 113 | 572 | 13.6 | (11.2–16.1) | 1.01 | (0.83–1.22) | 0.99 | (0.81–1.20) |
| No | 9385 | 1442 | 1013 | 14.0 | (13.2–14.9) | 1 | (ref.) | 1 | (ref.) |
| Statins | |||||||||
| Yes | 1145 | 172 | 556 | 15.0 | (12.9–17.1) | 0.98 | (0.81–1.16) | 1.05 | (0.88–1.26) |
| No | 9013 | 1383 | 1051 | 13.8 | (13.1–14.5) | 1 | (ref.) | 1 | (ref.) |
| Trauma diagnosis † | |||||||||
| Yes | 6121 | 927 | 859 | 13.8 | (13.0–14.7) | 1.14 | (1.03–1.27) | 1.13 | (1.02–1.26) |
| No | 4037 | 628 | 1177 | 14.0 | (13.0–15.1) | 1 | (ref.) | 1 | (ref.) |
| PDMD Ω | |||||||||
| Yes | 215 | 30 | 368 | 12.3 | (7.9–16.7) | 1.05 | (0.71–1.49) | 1.14 | (0.77–1.63) |
| No | 9943 | 1525 | 996 | 13.9 | (13.3–14.6) | 1 | (ref.) | 1 | (ref.) |
*95% Confidence interval
** Adjusted for age, sex, calendar period, time since admittance -, and length of hospital stay for the primary SDH, as well as all the listed potential predictors for recurrent SDH.
***Adjusted for the use of platelet inhibitors and warfarin.
† Trauma diagnosis less than 2 years before the primary SDH.
Ω PDMD: Pre-packaged Daily Medication Doses.