# P-1573. Healthcare Costs Associated With Lyme Disease Among Medicare Fee-for-Service Beneficiaries in the United States: A Retrospective Claims-Based Study

## TL;DR

This study finds that older adults with Lyme disease in the US face high healthcare costs, especially those with more severe cases.

## Contribution

The study provides the first detailed analysis of Medicare healthcare costs associated with Lyme disease in older adults.

## Key findings

- Disseminated Lyme disease cases had the highest mean LD-specific costs at $4,554.
- All-cause costs increased significantly for all LD subgroups at 6-month follow-up.
- Strategies to prevent LD in older adults could reduce the economic burden.

## Abstract

Lyme disease (LD) is the most common tick-borne illness in the United States (US). Incidence peaks in older adults, yet LD-associated healthcare costs are understudied in this population. This retrospective, observational study assessed LD-associated healthcare costs among US Medicare Fee-for-Service (FFS) beneficiaries aged ≥ 65 years.

Eligible LD cases were identified in Medicare FFS claims data (Medicare Parts A, B, and D) from Jan 2016–Jul 2023, had continuous eligibility for the assessment period, and had ≥ 1 outpatient or inpatient LD claim. Outpatient claims had an LD diagnosis code (A69.xx) with qualifying antibiotic treatment within 30 days. Inpatient claims had a primary LD diagnosis code or a secondary LD diagnosis code with a primary LD-linked condition. Cases were classified into subgroups (localized, disseminated, indeterminate) based on LD-associated diagnosis codes, outpatient and inpatient services, and antibiotics. Outcomes included LD-specific (medical) costs during individual LD episodes and all-cause (medical and pharmacy) costs at 6-month follow-up versus 6-month baseline. Comparisons used a paired t test for continuous measures, with significance noted at P< 0.001.

Among 121,941 identified LD cases, 53.0% were female, 93.4% were White, and the mean (standard deviation) age was 74.0 (6.0) years. Of these, 62.2% had localized LD, 21.3% had disseminated LD, and 16.6% had indeterminate LD. Mean LD-specific total (medical) costs were $1,513 overall and were highest for disseminated cases ($4,554) (Figure 1). Mean all-cause total costs at 6-month follow-up versus 6-month baseline were significantly higher for LD cases overall (Δ$4,378), localized LD cases (Δ$2,638), disseminated LD cases (Δ$9,888), and indeterminate LD cases (Δ$3,841) (Figure 2).

US Medicare FFS beneficiaries with LD incurred substantial healthcare costs, especially those with disseminated disease. Strategies to prevent LD cases in older adults may decrease associated economic burden.

Holly Yu, MSPH, Pfizer Inc.: Employee; may hold company shares and/or stocks. Peter Kardel, MA, ADVI Health LLC: Employee; may hold company shares and/or stocks. Heidi De Souza, MPH, ADVI Health LLC: Employee; may hold company shares and/or stocks. L. Hannah Gould, PhD, MS, MBA, Pfizer Inc.: Employee; may hold company shares and/or stocks.