Financial Impact of Tumor Lysis Syndrome Among Inpatients in the United States

Background

With an estimated 0.1 million cases in 2014, lymphomas and acute leukemias are the leading causes of malignancies in the US. Tumor lysis syndrome (TLS) is a potentially devastating complication associated with hematologic malignancies leading to increased morbidity and mortality. Previous European studies have shown that the financial burden of TLS is high, with an estimated cost of 7,342 Euros ($10,320 US Dollars) per admission. However, there is a paucity of data on the economic impact of TLS among US inpatients.

Methods

We used the Nationwide Inpatient Sample database to identify hospitalized patients aged ≥18 years with a primary diagnosis of TLS (International Classification of Diseases, 9^th Revision, Clinical Modification [ICD-9-CM] code 277.88) from the first year the diagnosis code was introduced (2009) to 2011. Nationwide Inpatient Sample is the largest all-payer publicly available inpatient care database in the US. It contains data from five to eight million hospital stays from about 1,000 hospitals across the country and approximates a 20% sample of all US hospitals. We calculated the mean length of stay (LOS) and mean hospital charges per TLS admission and compared them with those of overall inpatient admissions. Given that renal failure occurs in severe cases, we compared the mean LOS and hospital charge between TLS patients with and without RRT (hemodialysis or peritoneal dialysis, ICD-9-CM procedure codes 39.35 and 54.98 respectively). Data analysis was done using STATA version 13.0 (College Station, TX).

Results

We identified 997 admissions with TLS. Mean age was 67.5 (±3.3) with 62% males and 80.4% whites. Overall mean LOS and hospital charge for TLS during the study period was 8.02 days (SE 0.83) and $ 72,840 (SE 8,083). Both the mean LOS and hospital charge for TLS were significantly higher than overall in-patient admissions (Table 1). A total of 949 patients (95%) underwent RRT. There was no significant difference in mean LOS (9.84 days vs 7.94 days, p=0.28) and mean hospital charge ($ 88,098 vs $ 71,930, p=0.58) in patients with TLS that underwent RRT compared (95.2%, n=949) to patients that did not undergo RRT (4.8%, n=48).

Conclusion

Our study shows that TLS is associated with a significant economic burden, with a mean cost of $ 72,840 per TLS hospitalization. Although majority of the patients hospitalized for TLS received RRT, its use was not associated with significantly higher costs. Further studies are warranted to determine the ways of optimizing current preventive measures and to explore the drivers of increased in-hospital costs in TLS patients.

LOS=Length of Stay; TLS=Tumor Lysis Syndrome; USD=US Dollars