Inter-observer reliability of a risk assessment model for venous thromboembolism in acutely-ill medical hospitalized patients: Results from a prospective cohort study.

OBJECTIVES: To analyze the inter-observer reliability of risk for venous thromboembolism (VTE) in a population of adult acutely-ill medical patients. METHODS: In this prospective cohort study, we collected risk factors and risk classification for VTE using RAM IMPROVE7. Kappa statistics was used to evaluate inter-observer reliability between lead clinicians and trained researchers. We evaluated occurrence of VTE in patients with mismatched classification. RESULTS: We included 2,380 patients, median age 70 years (interquartile range [IQR], 58-79), 56.2% female. Adjusted Kappa for VTE risk factors ranged from substantial (0.64, 95% confidence interval [CI], 0.61-0.67) for "immobilization", to almost perfect (0.98; 95% CI 0.97-0.99) for "thrombophilia"; risk classification was 0.64 (95% CI 0.60-0.67). Divergent risk classification occurred in 434 patients (18.2%) of whom seven (1.6%) developed VTE. CONCLUSION: Despite substantial to almost perfect reliability between observers for risk factors and risk classification, lead clinicians tended to underestimate the risk for VTE.