Incidence Of Comorbidities In Medicare Beneficiaries Diagnosed With Acute Lymphoblastic Leukemia
Authors: Cetin Kara , Danese Mark , Katz Aaron J , Kelsh Michael A , Gleeson Michelle , Alekar Shilpa S. , Griffiths Robert 
Published: October 2019

Abstract

Background
The presence of comorbidities, including infections and neurological conditions, among older patients with acute lymphoblastic leukemia (ALL) may impact treatment decisions and influence patient prognosis. Thus, understanding the epidemiology of comorbidities among patients with ALL is useful for identifying subpopulations most likely to benefit from treatment. However, literature describing the epidemiology of comorbidities among older patients with ALL is sparse.

Objective
To characterize the incidence of comorbidities among older adults with ALL in routine clinical practice.

Methods
Using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, we identified a cohort of Medicare beneficiaries with a primary cancer diagnosis of ALL between 2000 and 2007. Individuals from a random 5% sample of cancer-free Medicare beneficiaries residing in SEER regions were matched (1:1) to ALL patients on year of diagnosis (i.e., the cancer-free individual was enrolled in Medicare Parts A and B during the same year), and county of residence. Individuals were required to be enrolled in Medicare Parts A and B for ≥ 4 months prior to diagnosis or index date (i.e., June 1st of the matched year for cancer-free individuals). Time-at-risk for each comorbidity began on the diagnosis or index date and continued until the first of the following events: a claim for the comorbidity, change in Medicare coverage, death, or end of follow-up. Patients were identified with a comorbidity if they had ≥ 2 outpatient claims at least 30 days apart, or 1 inpatient claim with an appropriate diagnosis code. Three- and 12-month crude incidence rates were estimated for a broad range of comorbidities.

Results
There were 646 Medicare beneficiaries with a primary diagnosis of ALL and 646 cancer-free individuals. Incidence rates of comorbidities selected based on clinical relevance and/or large observed differences between patients with ALL and cancer-free individuals are presented (Table). In general, 3- and 12-month incidence rates were considerably higher among ALL patients than in cancer-free individuals.

Conclusions
In older adults with ALL, there is a high incidence of comorbidities, including infections and neurological conditions. The incidence rates of comorbidities are particularly high within the first 3 months of diagnosis, but remain elevated even when observation time is extended up to 12 months following diagnosis. High incidence rates of comorbidities may be attributable to ALL and/or toxicities associated with therapy, or may represent recognition of prevalent conditions at the time of ALL diagnosis.

Disclosures:
Cetin: Amgen, Inc.: Employment. Danese:Amgen, Inc.: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; MedImmune: Consultancy, Research Funding. Katz:Amgen, Inc.: Employment. Kelsh:Amgen, Inc.: Employment. Gleeson:Amgen, Inc.: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; MedImmune: Consultancy, Research Funding. Alekar:Amgen, Inc.: Employment. Griffiths:Amgen, Inc.: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; MedImmune: Consultancy, Research Funding.