title: Explicit versus implicit risk assessment for the indication of antithrombotic prophylaxis in acutely ill medical in-patients.
abstract: OBJECTIVE
  The indication of venous thromboembolism (VTE) prophylaxis in acutely ill patients admitted to medical departments is not well-defined. Consensus groups have published recommendations and guidelines, addressing this issue. We investigated whether a guideline (explicit risk assessment) would improve the formerly used implicit risk assessment.
  
  
  METHODS
  We compared two groups of patients consecutively admitted to our department during a 4-months period each. Group 1 was assessed prospectively and treated according to a guideline (explicit assessment). Group 2 consisted of the patients hospitalised in the four months prior to the introduction of the guideline (implicit assessment). Their data were abstracted retrospectively from the medical charts. Main outcome measures were symptomatic VTE and major bleedings, and the consumption of unfractionated (UFH) and fractionated (LMWH) heparins. Follow-up lasted until 90 days after hospital discharge.
  
  
  RESULTS
  Symptomatic VTE occurred in 5/686 (0.7%) patients of group 1 vs 9/622 (1.4%) patients of group 2 during the hospital phase (p>0.05), and in 9/646 (1.4%) vs 10/572 (1.7%) during the whole study period (p>0.05). In group 1, 350 (51%) patients did not qualify for thromboprophylaxis according to the guideline, and none of them experienced any symptomatic VTE event. Three patients (0.5%) in group 1 and 4 patients (0.6%) in group 2 experienced a major bleeding event (p>0.05). Average consumption of UFH and LMWH did not differ between the groups.
  
  
  CONCLUSIONS
  The introduction of a guideline for explicit assessment of thromboembolic risk was not significantly superior to the formerly used implicit assessment. However, based on the small number of events observed in this study, a minor advantage cannot be ruled out. Targeted indication for thromboprophylaxis, whether explicit or implicit, avoided application of UFH or LMWH in half of the patients in our setting.
authors.affiliation: Department of Internal Medicine, Cantonal Hospital of Schaffhausen, Switzerland. sigmund.ruettimann@kssh.ch
authors.forename: Sigmund
authors.initials: S
authors.lastname: Rüttimann
authors.forename: Markus
authors.initials: M
authors.lastname: Danner
authors.forename: Markus G
authors.initials: MG
authors.lastname: Glaser
mesh_terms: D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans; D007297:Inpatients; D008297:Male; D018570:Risk Assessment / Q000379:methods*; D013557:Switzerland; D013923:Thromboembolism / Q000517:prevention & control*; D020246:Venous Thrombosis / Q000517:prevention & control*
chemical_list: D005343:Fibrinolytic Agents