Efficacy and safety of anticoagulation dose reduction for venous thromboembolism prophylaxis in low body weight patients: a systematic review and meta-analysis

BACKGROUND: Venous thromboembolism (VTE) is a common complication among hospitalized patients, hence VTE prophylaxis is essential. Low body weight patients are at an increased risk of bleeding however there are no guideline recommendations regarding dose adjustment in this population. We performed a meta-analysis to determine whether dose reduction for VTE prophylaxis in low-body weight patients reduces the risk of bleeding, without compromising its efficacy. METHODS: We searched electronic databases from inception to October 2024. We did a random-effects meta-analysis using RevMan 5.4. Data were pooled to obtain a risk ratio (RR) with 95% confidence interval (CI). Heterogeneity and publication bias were assessed with statistic and funnel plot, respectively. Risk of bias was assessed using ROBINS-I and certainty of evidence was assessed using GRADE. RESULTS: Seven observational studies with 5,575 individuals were included. Pooled analyses revealed no significant difference in risk of total bleeding [RR 0.78, 95% CI 0.48–1.26] and major bleeding [RR 0.62, 95% CI 0.33–1.15] with reduced dose compared to standard dose anticoagulation, however with high heterogeneity (I2 = 64%). Excluding studies with baseline characteristics increasing risk of bleeding in the reduced dose group, sensitivity analysis showed that dose reduction significantly decreases the risk of total [RR 0.49, 95% CI 0.30–0.82] and major bleeding [RR 0.42, 95% CI 0.22–0.80], with low heterogeneity (I = 0). In terms of efficacy, there is not enough evidence to show that anticoagulation dose reduction increases risk of VTE [RR 0.74, 95% CI 0.32–1.73]. CONCLUSION: Among low body weight patients, dose reduction for VTE prophylaxis may reduce risk of bleeding, especially major bleeding, without compromising its efficacy in preventing VTE, hence it can be considered in this population. Randomized controlled trials are needed to further support this recommendation.