Epidemiology of venous thromboembolism in patients with liver diseases: a systematic review and meta-analysis

The risk of venous thromboembolism (VTE) may be increased in patients with liver diseases. A systematic review and meta-analysis were conducted to analyze the epidemiology of VTE in such patients. All relevant studies were searched via the PubMed, EMBASE, and Cochrane Library databases. The incidence and prevalence of VTE were pooled using random-effect models. Subgroup analyses were conducted according to the type of VTE [deep vein thrombosis (DVT), pulmonary embolism (PE)], type of liver disease (liver cirrhosis alone/unclassified liver diseases or non-cirrhotics), region in which the study was performed (USA/Europe/Asia), number of total observed patients with liver diseases (> 1,000/< 1,000 patients), study quality (high/low), and methods for identifying the cases (ICD codes/clinical charts). Of 4,843 papers initially identified, 20 were included. The incidence of VTE varied from 0.33 to 6.32 % in 14 studies with a pooled value of 1 % (95 % confidence interval (CI) 0.7-1.3 %). The pooled incidence of DVT and PE was 0.6 % (95 % CI 0.4-0.8 %) and 0.28 % (95 % CI 0.13-0.49 %), respectively. The prevalence of VTE varied from 0.6 to 4.69 % in six studies with a pooled value of 1.0 % (95 % CI 0.7-1.2 %). The pooled prevalence of DVT and PE was 0.7 % (95 % CI 0.6-0.9 %) and 0.36 % (95 % CI 0.13-0.7 %), respectively. The heterogeneity was statistically significant in the main and subgroup meta-analyses. In conclusion, about 1 % of patients with liver diseases develop or are diagnosed with VTE during their hospitalizations. However, the epidemiological data are very heterogeneous among studies.