Differences In Treatment Patterns and Costs Among Diffuse Large B-Cell Lymphoma Patients Treated In The Clinic Vs. The Hospital Outpatient Setting
Authors: Reyes Carolina , Byfield Stacey Dacosta , Becker Laura K. , Small Art 
Published: October 2019

Abstract

Background
Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of Non-Hodgkin's Lymphoma (NHL) accounting for approximately 30% of newly diagnosed casesi. DLBCL is an aggressive form of NHL and without treatment, median survival estimates are <1 year.ii Rituximab in combination with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) is recommended first-line therapy for DLBCL patients and has been shown to improve overall survival compared with CHOP alone (previous standard therapy).iii In addition, published evidence suggests that receipt of granulocyte-colony stimulating factor (G-CSF) may improve outcomes among patients who initiate CHOP-based therapy.iv
It is unclear whether differences in treatment and outcomes exist among cancer patients by site where care is delivered. This study examines differences in treatment patterns, health care resource use and costs among DLBCL patients receiving rituximab (R) or R+ chemotherapy in the office/clinic (OC) setting vs. the hospital outpatient (HOSP) setting.

Methods
This retrospective study used medical and pharmacy claims (1/2007 - 7/2012) from a national US commercial health plan to identify patients at least18 years old with ≥2claims for R. Patients were required to have evidence of DLBCL (≥1 claim with ICD-9-CM 200.78 or ≥2 claims with unique diagnosis codes from ICD-9-CM 200.70 to 200.77) and be enrolled in the health plan for ≥6 months before and after the index date (date of the first R claim). The follow-up period, that is, the episode of care (EOC), was the date of the first R infusion through 30 days after the last infusion prior to a gap in R administration of at least 7 months; those with less than 6 months of follow-up due to death were included. Patients with multiple cancers or receipt of R at both the OC and HOSP setting during the EOC were excluded. Differences in number of infusions, receipt G-CSF, healthcare utilization and per-patient per-month (PPPM) health care costs by cohort were examined.

Results
A total of 491 patients were identified, 65% OC (n=320) and 35% HOSP (n=171): by insurance type, 140 Medicare Advantage patients, 39% HOSP and 351 commercially insured patients, 33% HOSP. From 2007 to 2011/2012, the percentage of patients in HOSP increased from 32% to 43%.
Descriptive results are shown in the Table. The cohorts had similar mean age, baseline Charlson comorbidity index scores and similar EOC lengths. However, compared to the OC cohort, the HOSP cohort had fewer infusions during the EOC and fewer infusions per month. In addition, fewer HOSP patients had evidence of combination therapy and receipt of any G-CSF during the EOC. HOSP patients also had significantly higher rates of emergency room visits, but not hospitalizations compared to OC patients. Total PPPM costs during the EOC as well as average costs of anti-cancer systemic therapy drugs plus administration costs incurred on days of rituximab infusions were significantly higher among the HOSP cohort compared to the OC cohort.

Conclusions
Increasing proportions of DLBCL patients receive infusions in the HOSP setting. HOSP patients had fewer infusions per month and incurred greater costs on the day of infusion compared to the OC cohort. There were fewer patients in HOSP with evidence of G-CSF during the EOC compared to OC patients. Overall, total PPPM costs were higher among the HOSP cohort compared to the OC cohort. Future research is warranted to assess the impact of these differences on clinical outcomes by site of care.
[i] Armitage et al. JCO 1998;16(8):2780-95
[ii] Mey et al. Swiss Med Wkly 2012;140:w13511
[iii] NCCN Guidelines Version 1.2013 Diffuse Large B-cell Lymphoma
[iv] Donnelly, et al, Leuk Lymphoma. 2000;39(1-2):67-75

Disclosures:
Reyes: Genentech, inc: Employment, Equity Ownership. Dacosta Byfield:Genentech, Inc: Genentech contracted with OptumInsight to conducting the work described in the abstract. Stacey is employed at Optum but did not receive funds directly from Genentech and employment is not contingent on work with Genentech., Genentech contracted with OptumInsight to conducting the work described in the abstract. Stacey is employed at Optum but did not receive funds directly from Genentech and employment is not contingent on work with Genentech. Other; OptumInsight: Employment. Becker:Genentech, Inc: Genentech contracted with OptumInsight to conducting the work described in the abstract. Laura is employed at Optum but did not receive funds directly from Genentech and employment is not contingent on work with Genentech., Genentech contracted with OptumInsight to conducting the work described in the abstract. Laura is employed at Optum but did not receive funds directly from Genentech and employment is not contingent on work with Genentech. Other; OptumInsight: Employment. Small:Genentech, Inc: Employment, Equity Ownership.