Health care quality and outcomes among medicare patients with guillain-barré syndrome

The National Institute of Neurological Disorders and Stroke awarded the University of South Carolina $237,254 on September 1, 2026, under the Extramural Research Programs in the Neurosciences and Neurological Disorders program (CFDA 93.853) to conduct a national retrospective cohort study of health care quality and outcomes among Medicare patients with Guillain-Barre syndrome.

The recipient will perform a retrospective analysis of traditional Medicare claims and Medicare Advantage encounter data from 2016 through 2024 linked with facility-level data from CMS Care Compare, Provider of Service files, and post-acute patient assessment data. The project addresses three primary aims: quantifying diagnostic delays in Guillain-Barre syndrome and their association with patient outcomes including mortality and time to recovery; identifying patient and hospital factors associated with in-hospital mortality and potentially preventable healthcare-acquired conditions to highlight quality improvement opportunities in acute care; and evaluating patients' access to high-quality post-acute care and assessing how post-acute care factors influence recovery. The study targets a rare but potentially severe inflammatory neuropathy affecting one to two cases per 100,000 annually, for which substantial knowledge gaps exist regarding variation in care delivery and its relationship to patient outcomes, particularly between traditional Medicare and Medicare Advantage beneficiaries.

Work is performed in Columbia, South Carolina. The period of performance runs from September 1, 2026, through July 31, 2028.

Abstract

Guillain-barré syndrome (GBS) is a rare but potentially severe inflammatory neuropathy (1 - 2 cases per 100,000 annually) that causes numbness, muscle weakness, and autonomic dysfunction. In severe cases, IT can lead to paralysis, respiratory failure, or death. While most individuals recover following treatment with intravenous immunoglobulin or plasma exchange, others remain permanently disabled, and 1-year mortality ranges from 3 - 20%. Because GBS is uncommon, patients with this condition are a hard population to study. Consequently, little is known about the extent to which variation in care delivery exists or how IT is associated with patient outcomes. Critical knowledge gaps remain regarding: 1) the occurrence of diagnostic delays and their association with patient outcomes, 2) factors associated with variation in acute hospital outcomes, and 3) access to high-quality post-acute care and its association with recovery. Moreover, IT is unknown whether these relationships differ between traditional medicare and medicare advantage plans, which now enroll a majority of beneficiaries. To address these gaps, we propose a national retrospective cohort study of GBS patients using traditional medicare claims and medicare advantage encounter data from 2016 - 2024, linked with facility-level data from CMS care compare and the provider of service files as well as post-acute patient assessment data. Aim 1 will quantify diagnostic delays and determine their association with patient outcomes, including mortality and time to recovery. Aim 2 will identify patient and hospital factors associated with in- hospital mortality and potentially preventable healthcare-acquired conditions, highlighting opportunities for quality improvement in acute GBS care. Aim 3 will evaluate patients' access to high-quality post-acute care and assess how post-acute care factors, including quality, are associated with recovery, functional improvement, and mortality. The proposed study is innovative in its integration of national medicare and medicare advantage data with comprehensive information on hospital and post-acute care facility characteristics, quality measures, and patient-level health assessment data. Together, these linkages will enable US to conduct the first comprehensive evaluation of care quality and outcomes for GBS across the full care continuum from diagnosis through recovery. Understanding which GBS patients are at greatest risk of experiencing diagnostic delays, adverse events, and prolonged recovery is significant because IT will identify key points along the care continuum where clinical and systems-level interventions, including targeted quality improvement efforts, predictive modeling, and development of clinical decision support tools, are most likely to improve patient outcomes for this potentially devastating condition. By advancing a data-driven framework to evaluate care delivery for rare neurological conditions, this study will also establish a generalizable approach to improving quality and outcomes for other rare but serious diseases.