# Investigating the Secondary Care System Burden of Glycogen Storage Disease Type Ia (GSDIa) Using the Hospital Episode Statistics Database

## TL;DR

This study shows that Glycogen Storage Disease Type Ia causes a high healthcare burden in England, with frequent hospital visits and higher mortality compared to the general population.

## Contribution

The study quantifies the secondary care burden of GSDIa using a national hospital database in England.

## Key findings

- Patients with GSDIa had an average of 8 hospital events per year, much higher than the general population's 1 event per year.
- Adolescents with GSDIa had the highest number of events (28.5 on average), and mortality was 4.3% compared to 0.9% in the general population.
- Infants with GSDIa had the longest average hospital stays, with 4.6 days for nonelective and 3.4 days for elective events.

## Abstract

Background: Glycogen storage disease type Ia (GSDIa) is a rare, inherited metabolic disorder characterized by a deficiency in glucose 6-phosphatase. People living with GSDIa are at high risk for clinical manifestations (including hypoglycemia and hepatomegaly) and clinical complications (including hyperlipidemia, stunted growth, liver adenomas, and renal failure). Evaluating symptom management and secondary care burdens is vital to understanding the patient experience and optimizing care pathways. Objective: We sought to quantify the number of patients with GSDIa within secondary care settings across England and to evaluate the burden of disease associated with living with GSDIa. Methods: This study utilized the United Kingdom Hospital Episode Statistics (HES) database across a 69-month time period (April 2015–December 2020) to investigate National Health Service (NHS) resource use and GSDIa mortality. Results: Patients (N = 943) with GSDIa were identified. Frequent manifestations included anemia (n = 421; 45%), hypoglycemia (n = 185; 20%), and hepatomegaly (n = 152; 16%). On average, patients had a total of 8 events/year, including 2 elective events, 2 nonelective emergencies, 1 outpatient visit, and 3 daycase visits. In the entire HES population, there was approximately 1 (~60% elective, ~40% nonelective) event/year. The highest total number of events across the entire patient journey tracked within the HES occurred with adolescents (12-17 years) who had an average of 28.5 events. Average length of stay was greatest in the pediatric infantile (0-2 years) population with 4.6 days and 3.4 days for nonelective and elective events, respectively. When benchmarked against the general population, patients with GSDIa had a mortality rate of 4.3%, compared with 0.9% for the entire HES population. The average age at mortality was 14.3 years lower for patients with GSDIa vs the entire HES population (63.7 years vs 78.0 years). Discussion: This study demonstrates high burden associated with GSDIa. Complications are a key driver of NHS resource use. Mortality associated with GSDIa in hospitalized patients is higher than the general population. Conclusions: GSDIa imposes a large burden on the healthcare system. There is a clear unmet need for patients with GSDIa, and complications are a substantial driver of resource use and burden of disease.