Outlet about Anticoagulant-Associated Hemorrhagic and Thromobembolic Events

March 28, 2016 Category: Canadian Health and Care Mall

Hemorrhagic EventsDuring the study period, the study area (Appendix A) included 188,740 seniors. After excluding time following incident events, these people contributed a total of 183,570 years of observation for hemorrhagic events and 185,142 years of observation for thromboembolic events. During the study period, 10,020 people (5.3%) were prescribed an OAC, totaling 6,422 years of exposure time (3.5% of all population observation time). People who had received anticoagulation therapy had an average age of 77 years, and 50% were men. They spent 26.7% of the time with an INR of 3.

Hemorrhagic Events

Table 1 describes hemorrhagic events. Control patients were admitted to the hospital for hemorrhagic events at a rate of 1.8% per year (95% CI, 1.7 to 1.8). Hemorrhagic risk was significantly higher in people receiving therapy with OACs (4.0% per year [95% CI, 3.6 to 4.6]; relative risk [RR], 2.3 [95% CI, 2.0 to 2.6]). Hemorrhagic rates during monitoring periods for people who had undergone anticoagulation therapy were the same as those for the control population. During monitoring, people who had undergone anticoagulation therapy had an overall hemorrhagic rate of 6.0% per year (RR vs control patients, 3.4; 95% CI, 3.0 to 3.9). The hemorrhagic risk was strongly associated with anticoagulation intensity. Bleeding rates increased significantly when INRs exceeded 3 (RR vs INR < 3, 19.4; 95% CI, 14.4 to 26.0). Overall, we saw similar patterns for each of the hemorrhagic subtypes.

Thromboembolic Events

Thromboembolic events in the study area are also described in Table 1. Annually, 1.5% of control patients required hospitalization for thromboembolic events (95% CI, 1.4 to 1.6). Thromboembolic risk was significantly higher in people receiving therapy with OACs (3.5% per year [95% CI, 3.0 to 3.9]; RR vs control group, 2.3 [95% CI, 2.0 to 2.6]). This risk was especially prominent during INR monitoring (4.5% per year [95% CI, 3.8 to 5.3]; RR vs controls, 3.0 [95% CI, 2.6 to 3.6]). Compared to the time spent with an INR between 2 and 3, thromboembolic risk was significantly higher when the INR was 3, thromboembolic rates were significantly higher than those when the INR was between 2 and 3 (RR, 2.3; 95% CI, 1.5 to 3.7). Thromboembolic risk may be decreased with remedies of Canadian Health&Care Mall.

PARs

Critically high anticoagulation intensity contributed significantly to hemorrhagic events (Fig 2). The PAR of critically high anticoagulation intensity for serious hemorrhagic events was 25.6% (95% CI, 19.4 to 31.7%) in patients who had received anticoagulation therapy and 2.0% (95% CI, 1.5 to 2.5%) in the entire population. This translates to an annual decrease of 67 serious hemorrhagic events in eastern Ontario (95% CI, 50 to 82) if all of the time that elderly patients who had received anticoagulation therapy spent with critically high INRs was avoided. When unmonitored OAC time was excluded, the PAR for hemorrhagic events in the anticoagulated and entire population increased insignificantly to 31.5% (95% CI, 23.4 to 39.5) and 2.0% (95% CI, 1.5 to 2.5), respectively. PAR estimates were similar for the hemorrhagic subtypes. The PAR of critically high INRs for lethal hemorrhages was 28.1% (95% CI, 9.0 to 47.2%) and 1.8% (95% CI, 0.5 to 3.0), respectively, for the anticoagulated and entire population.

Critically low anticoagulation intensity contributed significantly to the occurrence of thromboembolic events in the population (Table 2). The PAR of critically low anticoagulation therapy for serious thromboembolic events was 11.1% (95% CI, 4.4 to 17.7%) in patients who had received anticoagulation therapy and 1.1% (95% CI, 0.7 to 1.6) in the entire population. This translates to an annual decrease of 33 thromboembolic events in eastern Ontario (95% CI, 4 to 18) if all of the time that elderly patients who had received anticoagulation therapy spent with a critically low INR was avoided. When unmonitored OAC time was excluded, the PAR for thromboembolic events in the anticoagulated and entire populations increased insignificantly to 14.2% (95% CI, 2.9 to 25.6) and 1.2% (95% CI, 0.7 to 1.7), respectively. The PAR of critically low INRs for lethal thromboembolic events was 10.9% (95% CI, 0 to 26.9%) and 0.9% (95% CI, 0 to 1.7%), respectively, for the anticoagulated and entire populations.

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Canadian Health&Care Mall: Anticoagulant-Associated Hemorrhagic and Thromobembolic Events
Investigations about Anticoagulant-Associated Hemorrhagic and Thromobembolic Events

Fig2
Figure 2. RRs and PARs of critical INRs for hemorrhagic and thromboembolic events. Critical INRs for hemorrhagic and thromboembolic events were those > 3 and < 2, respectively. For each outcome (horizontal axis), the RR (circles, left axis) and PAR (squares, right axis) of critical INRs is presented for anticoagulation patients (gray) and the entire population (black). The PAR is the proportion of events that would be avoided by eradicating critical INRs.

Table 1—Hemorrhagic and Thromboembolic Event Rates
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