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Table 3 Risk of death by initial dosing strategy of thromboprophylaxis

From: Dosing of thromboprophylaxis and mortality in critically ill COVID-19 patients

Initial dosing strategy of thromboprophylaxis No. of patients Events/person-days IR per 1.000 person-days (95% CI) HR (95% CI) of death ≤ 28 days
Univariable model Multivariable modela Multivariable imputed modelb
High dosec 37 5/923 5.4 (2.3–13.0) 0.31 (0.12–0.82) 0.33 (0.13–0.87) 0.30 (0.11–0.81)
Medium dosed 48 12/1182 10.2 (5.8–17.9) 0.59 (0.30–1.16) 0.88 (0.43–1.83) 0.87 (0.42–1.82)
Low dosee 67 26/1453 17.9 (12.2–26.3) 1.00 (Ref.) 1.00 (Ref.) 1.00 (Ref.)
  1. Risk of death during the first 28 days among 152 patients admitted to the intensive care unit due to COVID-19 at Södersjukhuset, Stockholm, March 6 to April 30, 2020, by initial dosing strategy with tinzaparin/dalteparin as thromboprophylaxis
  2. CI, confidence interval; IR, Incidence Rate; HR, Hazard Ratio
  3. aAdjusted for sex, age (continuously), body mass index (</≥ 30 kg/m2 and missing [n = 6]), invasive mechanical ventilation (yes/no), and Simplified Acute Physiology Score III (continuously)
  4. bAdjusted like the multivariable model but with body mass index imputed due to missing values (n = 6), and flexibly modeled with restricted cubic splines at three knots over the percentile (10th, 50th, and 90th) distribution of body mass index in the population
  5. cTinzaparin, ≥ 175 IU/kg of body weight per daily, or dalteparin, ≥ 200 IU/kg of body weight daily
  6. dTinzaparin, > 4500 IU daily to < 175 IU/kg of body weight daily, or dalteparin, > 5000 IU daily to < 200 IU/kg of body weight daily
  7. eTinzaparin, 2500–4500 IU daily, or dalteparin, 2500–5000 IU daily