Impact of Evidence-Based Chemotherapy Regimens on Health Outcomes, Utilization and Cost for Diffuse Large-b-Cell Lymphoma (DLBCL) Patients

Introduction

Diffuse large-b-cell lymphoma (DCBCL), an important, prevalent sub-type of non-Hodgkin lymphoma, is treated with curative intent. A national commercial payer has designated certain chemotherapy regimens as "on-pathway" based on their efficacy, toxicities, and costs, to enhance high quality and affordable cancer care. This study compared health outcomes, healthcare utilization and cost among DLBCL patients receiving on-pathway versus off-pathway regimens.

Methods

Using administrative claims data and clinical data from the payer's Cancer Care Quality Program, we identified 1,012 DLBCL patients aged 18 or older, receiving first-line chemotherapy from 2014 to 2018. Those with a history of non-NHL cancer or prior exposure to chemotherapy were excluded. Outcomes, including complications, use of diagnostic imaging, additional therapies or treatments, hospice enrollment, all-cause mortality, healthcare utilization and cost, were assessed following chemotherapy until death or end of enrollment (up to 12 months). Generalized linear models examined the association between on-pathway regimens and outcome measures, adjusting for demographic characteristics, socioeconomic status, cancer stage, body mass index, comorbidities and healthcare utilization within 6 months prior to chemotherapy.

Results

A total of 695 (68.7%) patients received on-pathway regimens. Both groups had similar age (57.9 vs. 58.4, p=0.72), females (42.6% vs 44.8%, p=0.51) and follow-up time (10.6 vs.10.8 months). However, more on-pathway patients were obese (40.4% vs.33.8%, p=0.04) and had early-stage NHL (44.2% vs.24.0%, p=0.002).

The use of on-pathway regimens was associated with significantly lower risk for blood transfusion (adjusted odds ratio (AOR): 0.64, 95% CI: 0.45-0.91), similar risk for infections (AOR:1.05, 95%CI: 0.74 -1.49) and granulocytopenia (AOR:1.16, 95%CI: 0.81-1.67) compared to off-pathway regimens. The on-pathway group also had significantly more use of PET scan (incidence rate ratio (IRR): 1.12, 95% CI: 1.04-1.21), radiotherapy (IRR: 1.57, 95% CI: 1.07-2.31), and higher likelihood of using granulocyte colony stimulating factors (G-CSF)(AOR: 1.95, 95% CI: 1.33-2.87). One potential explanation for the observed difference in G-CSF use was that 93% on-pathway patients used regimens with intermediate risk for febrile neutropenia while more than 25% off-pathway regimens had low risk. There was no difference in the risk of hospice enrollment (adjusted hazard ratio (AHR)=0.97, 95%CI: 0.56-1.70) and all-cause mortality (AHR=0.97, 95%CI: 0.51-1.88) during follow-up.

Patients receiving on-pathway regimens had significantly fewer non-transplant hospital admissions (IRR: 0.75, 95% CI: 0.68-0.84), and lower overall healthcare costs (-$3,335 per patient per month, 95% CI: -$6,146 to -$525), mainly driven by the reduced hospital cost (-$2,517 per patient per month,95% CI: -$4,860 to -$173).

Conclusions

In our study, on-pathway regimens demonstrated lower risk of complications, and generally lower healthcare utilization and overall total costs. These findings provide a strong basis for promoting evidence-based chemotherapy regimens for DLBCL patients.