Morbidity, Mortality and Costs Associated with Venous Thromboembolism in Hospitalized Patients with Cancer

Background: Venous thromboembolism (VTE) occurs commonly in patients with cancer and is associated with considerable morbidity and mortality. While the risk of VTE is greater in hospitalized patients and those undergoing active treatment, less is known about factors associated with increased risk of mortality and costs in this setting. The study presented here evaluates the risk of mortality among hospitalized cancer patients with VTE and the association of patient comorbidities and infectious complications on duration of hospitalization, in-hospital mortality and costs.

Methods: Data on hospitalization of adult patients (age≥18) with cancer between 2004 and 2012 from 239 US academic medical centers reporting to the University Health Consortium were analyzed. For patients with multiple hospitalizations, the first admission during the time period studied was utilized. Primary outcomes consisted of length of stay, in-hospital mortality and estimated cost of hospitalization. Stratified analyses were performed based on patient characteristics, year of hospitalization, cancer type, major comorbidities and infectious complications. Costs were adjusted to 2014 dollars.

Results: Among more than 3.8 million admissions of adult patients with cancer, 246,653 included a diagnostic code for VTE representing 198,173 individual patients with both cancer and VTE. Overall, 41% of patients with cancer and VTE were hospitalized for 10 days or longer with an in-hospital mortality rate of 11.3% and estimated average costs per hospitalization of $37,039. While length of stay and mortality rates remained relatively stable over the 9 years of observation, 2014-adjusted costs per day hospitalization increased from $2,600 in 2004 to $3,200 in 2012. In-hospital mortality was greatest in patients with lung (15.8%) and gastric (14.1%) cancers and leukemia (14.2%). Medical comorbidities associated with the highest rates of mortality included congestive heart failure (19.8%), cerebrovascular disease (20.4%), and major disorders of the lung (20.6%), liver (20.0%), and kidney (21.4%) with mortality increasing in direct proportion to the number of comorbidities. Likewise, comorbidities associated with the greatest average costs per hospitalization included congestive heart failure ($51,885), cerebrovascular disease ($55,815), and major disorders of the lung ($53,899), liver ($51,332), and kidney ($55,774) with estimated costs increasing from $22,622 with no medical comorbidity to over $70,000 with four or more. Alternatively, infectious complications associated with the highest rates of mortality and greatest average costs were sepsis (38.1%; $90,529) and pneumonia (26.0%; $69,024).

Conclusions: Hospitalized patients with cancer and VTE are at considerable risk for prolonged hospitalization and in-patient mortality accompanied by considerable hospital costs. Patients with additional major comorbidities and infectious complications are at even greater risk of in-hospital mortality and substantially greater costs. Additional efforts to identify cancer patients at greater risk for VTE and its complications including prolonged hospitalization and in-hospital mortality are needed as well as better strategies and agents for reducing the risk and consequences of VTE.