Patient outcomes in myeloproliferative neoplasm-related thrombosis: Insights from the National Inpatient Sample

Abstract

Background: Philadelphia-negative myeloproliferative neoplasms (MPNs) - polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) - often present with thrombosis. We aimed to determine the inpatient mortality, cost of care, and length-of-stay among individuals with Philadelphia-negative MPNs who had arterial or venous thrombosis associated with admission versus those who were admitted for non-thrombosis-related events.

Methods: Using ICD-10M coding, we identified 7,128,770 patients from the National Inpatient Sample (NIS) database who were hospitalized in 2016. 31,302 patients had a diagnosis of a Philadelphia-negative MPN. Mortality, length-of-stay, and cost of care were compared between patients who had thrombosis included among the top three diagnoses and those who were admitted for other reasons. Chi-squared test for categorical variables and t-test for continuous variables were used to compare baseline characteristics. Final multivariable models were constructed to determine predictors of outcomes.

Results: Inpatient mortality was significantly higher among individuals with Philadelphia-negative MPN who had thrombosis associated with admission as compared to those who were hospitalized for other reasons (5.7% versus 3.1%, P < 0.001). Unadjusted cost of care was also significantly higher for patients with thrombosis as compared to those without thrombosis ($25,539.06 versus $19,002.72 USD, respectively, P < 0.001). Length-of-stay was longer among the former group as compared to the latter (8.26 versus 7.95 days, P = 0.0963). However, this finding did not reach statistical significance.

Conclusions: Hospitalization for MPN-related thrombotic events is associated with excess inpatient mortality and higher cost of care. However, thrombosis has no statistically significant effect on length-of-stay among this population. The underlying causes of mortality and cost disparities among patients with MPN-associated thrombosis warrant further investigation.

Keywords: Cancer; Epidemiology; Hematologic malignancies; Philadelphia-negative myeloproliferative neoplasms; Thrombosis.