Full Length ArticleVenous thromboembolism incidence, recurrence, and mortality based on Women's Health Initiative data and Medicare claims

- Medicare claims compared reasonably well to medical record adjudication for VTE.
- In a national cohort of older women, VTE incidence varied by race/ethnicity.
- Incidence was highest in African-Americans and lowest in Asians/Pacific Islanders.
- VTE recurrence and all-cause mortality were high, especially in women with cancer.
- High post-VTE mortality in cancer patients appears due to cancer rather than VTE.

IntroductionOur objective was to compare Medicare claims to physician review and adjudication of medical records for identifying venous thromboembolism (VTE), and to assess VTE incidence, recurrence, and mortality in a large national cohort of post-menopausal women followed up to 19 years.Materials and methodsWe used detailed clinical data from the Women's Health Initiative (WHI) linked to Medicare claims. Agreement between data sources was evaluated among 16,003 women during 1993-2010. A claims-based definition was selected to analyze VTE occurrence and impact among 71,267 women during 1993-2012.ResultsOur VTE definition had 83% sensitivity. Positive predictive value was 69% when all records were included, and 94% after limiting Medicare records to those with a WHI hospitalization adjudicated. Annualized VTE incidence was 4.06/1000 person-years (PY), recurrence was 5.30/100 PY, and both rates varied by race/ethnicity. Post-VTE mortality within 1 year was 22.49% from all causes, including 1.01% from pulmonary embolism, 10.40% from cancer, and 11.08% from other causes. Cancer-related VTE compared to non-cancer VTE had significantly (p < 0.001) higher recurrence (9.86/100 PY vs. 4.43/100 PY) and mortality from all causes (45.89% vs. 12.28%), but not from pulmonary embolism (0.40% vs. 1.27%).ConclusionsMedicare claims compared reasonably well to physician adjudication. The combined data sources provided new insights about VTE burden and prognosis in older women.