Linkage of Medicare insurance claims to police-reported motor vehicle crashes: advancing traffic safety research in older adult populations

TL;DR

This study links Medicare claims with police-reported crashes to better understand factors affecting older drivers' safety.

Contribution

A novel linkage of Medicare and crash data to study clinical factors influencing MVCs in older adults.

Findings

97.76% of linked individuals had Strong or Fair match quality.

Cataracts were the most prevalent diagnosed condition among older drivers.

Only 2.47% of linked individuals experienced an MVC.

Abstract

Motor vehicle crashes (MVCs) are a leading cause of injury among adults aged 65 years and older (“older adults”). As the number of older drivers grows, it is increasingly important to understand clinical factors associated with an increased risk of MVC. A major barrier, however, is the lack of data. To address this, we linked two large-scale administrative databases, the New Jersey Safety and Health Outcomes (NJ-SHO) Data Warehouse, which contains information on all police-reported crashes in New Jersey from 2004 to 2019, and Medicare Fee-for-Service (FFS) insurance claims, which contains health care encounters and prescription drug dispensings among older adults in the United States over the same period. This paper explains the linkage process, describes selected work leveraging these data to study MVCs in older drivers, and highlights features and strengths of this linkage for future research.

The NJ-SHO–Medicare linkage was performed using categories of name (first and last), sex, age (birth and death date), and residence (state and ZIP code). Matches were ranked by quality and overall confidence.

After comparing different match strategies, we accepted a match when (1) the name match quality was High or Medium and the age match was High or (2) the name, sex, and residence match categories were all High. Of the 2,722,773 individuals successfully linked, we accepted 2,661,782 matches (97.76% of individuals linked and 91.59% of those submitted for linkage). All accepted matches were Strong or Fair. Among accepted matches who enrolled in Medicare FFS in 2019, 342,422 (28.57%) were 65–69 years old, 619,437 (51.69%) were female, and 955,309 (79.72%) were non-Hispanic White. Only 29,561 (2.47%) experienced an MVC and 25,478 (2.13%) received a citation. The most prevalent clinical conditions ever diagnosed were cataracts (669,044; 55.83%); chronic pain, fatigue, and fibromyalgia (367,165; 30.64%); and glaucoma (287,420; 23.98%).

With extensive temporal and population coverage, the NJ-SHO–Medicare linkage supports studying the relationships between clinical exposures (e.g., medications ), driving events (e.g., crashes, citations) and medical care trajectories, which can help advance the driving safety of older adults and inform future efforts to integrate administrative data.

The online version contains supplementary material available at 10.1186/s40621-026-00658-5.

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