Factors influencing time to initiation of chemotherapy in elderly patients with diffuse large B-cell lymphoma (DLBCL)

Abstract

6630 Background: DLBCL is an aggressive lymphoma for which treatment should be initiated quickly. The purpose of this study is to identify factors associated with the time to initiation of chemotherapy and the incremental cost of care. Methods: We analyzed DLBCL patients diagnosed from 1998–2002 with 1 year of non-HMO coverage prior to diagnosis in the SEER-Medicare dataset. Time to initial chemoimmunotherapy (CT) and costs of care were identified through claims for inpatient, outpatient and physician services through 2005. Costs were compared to a random sample of non-cancer Medicare patients using linear regression. Time to CT was assessed using proportional hazards regression with censoring for death and end of coverage. Models were adjusted for age, race, gender, comorbidity score, year of diagnosis, region (cost model) and stage (time model). CT was classified using all claims after diagnosis. Results: There were 4,716 patients identified. The mean age at diagnosis was 77 years, 86% were white, 31% were stage IV and 53% were alive 12 months after diagnosis. The mean monthly cost for the first year after diagnosis was $8,003 higher in DLBCL patients than in typical Medicare patients. Only 7.164% of patients received CT within the follow up period. Median time to first CT was 57 days. The most common initial CT used was CHOP±R (63%). Older age and greater comorbidity burden were associated with longer times to first CT (p<0.01). Black and other race were also associated with a significantly longer time to first CT (p<0.01). Conclusions: DLBCL is associated with an increased incremental cost of care. The time to CT initiation was associated with several patient characteristics including age and race. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Genentech, Inc. Genentech Genentech