Authors: Adriana Boateng-Kuffour, Nanxin Li, Keval Chandarana, Vamshi Ruthwik Anupindi, Liang Chen, Michael Hull, Xiaoyu Zhou, Jason Gaglia, Mitch DeKoven, Beth Barber
Categories: Original Research, Type 1 diabetes, Severe hypoglycemic events, Diabetes-related complications, Healthcare costs
Source: Advances in Therapy
Severe hypoglycemic events (SHEs) impose substantial clinical and economic burden on people with type 1 diabetes (pwT1D), yet real-world data describing this burden remain limited in the U.S. hospital setting. This study examined T1D-related complications and direct medical costs in pwT1D hospitalized or treated in the emergency department (ED) for hypoglycemia.
IQVIA’s PharMetrics Plus database was used to identify adults with T1D who experienced at least 1 hypoglycemic event requiring an inpatient hospitalization or ED visit from April 2016-April 2020. The SHE date was defined as the date of the first hospital-treated SHE: a claim with a hypoglycemia diagnosis and an inpatient hospitalization or ED visit. Patients were followed up until the end of continuous enrollment or end of the study period (April 30, 2022). Prevalence of T1D-related complications were descriptively summarized, and all-cause direct medical costs were calculated as per-patient-per-year (PPPY). The study was conducted during a period of early adoption of advanced diabetes technologies, such as hybrid closed-loop systems, and only included direct medical costs, potentially underestimating total costs.
Among 4627 adults with T1D and hospital-treated SHEs, mean age was 41.4 years, 57.3% were male, and 93.4% had commercial insurance. Common comorbidities included hypertension (24.6%), anxiety (9.5%), and depression (9.3%). Prevalence of retinopathy, neuropathy, chronic kidney disease (any stage), coronary artery disease, and peripheral vascular disease were 38.6%, 38.6%, 17.7%, 13.2%, and 11.4%, respectively. Total all-cause direct medical costs averaged 59,719 in 2025 USD), driven primarily by inpatient hospitalization (mean—25,968 in 2025 USD). Among patients with a hospitalization, mean (SD) number of hospitalizations (PPPY) were 1.5 (3.6) and the average length of stay per patient (PPPY) was 5.0 (20.7) days.
High T1D-related complication rates and elevated direct medical costs highlight the complexity of pwT1D who experienced hospital-treated SHEs.
The online version contains supplementary material available at 10.1007/s12325-026-03505-7.
Keywords: Type 1 diabetes, Severe hypoglycemic events, Diabetes-related complications, Healthcare costs
Current standard of care treatment for people with type 1 diabetes (pwT1D) is exogenous insulin therapy [1, 2]. A serious, potentially life-threatening, adverse event associated with exogenous insulin therapy is severe hypoglycemic events (SHEs), defined as hypoglycemic events requiring third-party assistance for recovery [1, 3, 4]. SHEs may present with neurocognitive dysfunction leading to confusion, and without third party intervention, loss of consciousness, seizures, coma or even death can occur [1, 3, 4]. They also increase the risk of unintentional injury, such as falls and motor vehicle accidents [5].
Recognizing the symptoms of a hypoglycemic event can lead to prompt management with, for example, immediate consumption of oral carbohydrates or glucagon administration [1]. However, about 1 in 3 pwT1D report having impaired awareness of hypoglycemia (IAH), which involves diminished or absent physiological responses due to repeated exposure to hypoglycemia [6]. PwT1D with IAH are less able to recognize and promptly treat hypoglycemia symptoms, compounding risk of future SHEs up to sixfold [7].
For some pwT1D who experience an SHE, urgent medical attention is required, potentially including emergency department (ED) visits or inpatient hospitalization [8, 9]. In a study of over 500 people with type 1 and 2 diabetes experiencing SHEs, approximately 11.9% had an ED or inpatient visit within 24 h of the event [9].
In general, the literature reports isolated costs for hospitalizations involving hypoglycemic events without describing the total medical costs to manage this subgroup of pwT1D [8, 10]. This research examined T1D-related complications and estimated the annual direct medical costs for pwT1D with an ED visit or inpatient hospitalization involving a hypoglycemic event.
This retrospective cohort study utilized administrative claims data from IQVIA’s PharMetrics Plus database to identify pwT1D from April 1, 2016, through April 30, 2020. The overall study period was October 1, 2015, to April 30, 2022, to allow at least two years of follow-up. PharMetrics® Plus is a nationally representative source of fully adjudicated medical and pharmacy claims for commercially insured individuals in the U.S. The database contains longitudinal patient-level information on diagnoses, procedures, inpatient and outpatient services, prescription and office/outpatient administered drugs, and costs. This study used de-identified, retrospective administrative claims data and did not involve the collection or use of identifiable personal information. As such, institutional review board (IRB) approval was not required in accordance with the Health Insurance Portability and Accountability Act (HIPAA). Necessary permissions were obtained from IQVIA to access and use the data.
Adults with T1D who experienced a hospital-treated SHE, defined as an ED visit or inpatient hospitalization for hypoglycemia were identified. Patient identification was based on a validated claims-based algorithm using International Classification of Diseases, 9th and 10th Revision (ICD-9-CM and ICD-10-CM) diagnosis codes for T1D and hypoglycemia (Supplementary Table 1) [8, 11–13].
Eligible patients met all the following inclusion aged ≥ 18 years with an ICD-10-CM diagnosis code for T1D between April 1, 2016, and April 30, 2020 (the date of the first T1D diagnosis was defined as the T1D index date); continuous enrollment with medical and pharmacy benefits for 6 months prior to the T1D index date; a T1D to type 2 diabetes (T2D) diagnosis code ratio > 0.5, calculated as the number of T1D codes divided by the sum of T1D and T2D codes; and no baseline prescriptions for non-insulin antidiabetic drugs [12, 13]. As ICD codes alone may not reliably distinguish between T1D and insulin-treated T2D, a T1D-to-T2D code ratio greater than 1 ensures that the patient’s diagnostic history aligns more closely with T1D, improving the specificity of patient classification and reduce misclassification between T1D and T2D patients. Prescriptions for metformin, pramlintide, SGLT2 inhibitors, or GLP-1 receptor agonists were permitted, consistent with prior literature [12, 13].
Hospital-treated SHEs were defined as ≥ 1 claim with a hypoglycemia diagnosis (Supplementary Table 1) in any position in an inpatient or ED visit [11]. The date of the first hospital-treated SHE was defined as the SHE date for the study cohort. Patients were followed until the end of continuous enrollment or end of the study period (April 30, 2022).
Patients were excluded if they had any claim for secondary/gestational diabetes during the study period. Gestational diabetes was identified with ICD-10-CM codes E08.x, E09.x, E13.x, and O24.x. Patients were also excluded for data quality issues, including invalid year of birth or missing sex.
Demographics and clinical characteristics, including age, sex, payer type, index year, and geographic region were assessed at index and comorbidities of interest including hypertension, anxiety, depression, epilepsy/seizure, and autoimmune disease (autoimmune thyroid diseases, type A gastritis, celiac disease, vitiligo, rheumatoid arthritis, systemic lupus erythematosus, and Addison’s disease) were assessed during baseline period. Diabetes-related complications were identified as ≥ 1 medical claim with ICD-9-CM or ICD-10-CM diagnosis codes corresponding to the complication of interest during the post-index period (Supplementary Table 1). The following diabetes-related complications of interest were microvascular complications (retinopathy, neuropathy, and nephropathy), macrovascular complications (coronary artery disease, congestive heart failure, cerebrovascular disease, and peripheral vascular disease), and other diabetes-related complications (diabetes ketoacidosis, gastroparesis, and hyperlipidemia/atherosclerotic disease). Complications were ascertained longitudinally throughout the follow-up period, and patients were flagged as having complication if they had at least one relevant claim after the index date.
All-cause direct medical costs were assessed by setting of care, including inpatient, ED, outpatient, and pharmacy, and reported as per-patient-per-year (PPPY) in 2022 USD using the medical care component of the Consumer Price Index [14]. Cost for the hospital-treated SHE event, which enabled the identification of these patients, were also assessed.
Descriptive analyses were conducted for demographic and clinical characteristics, as well as the prevalence of complications of interest (using ICD-10-CM diagnosis codes in the variable follow-up period for all patients) and all-cause direct medical costs. Categorical variables were summarized as counts and percentages. Continuous variables were reported as mean and standard deviation (SD).
A total of 4,627 pwT1D with hospital-treated SHEs were identified (Supplementary Fig. 1). The mean age was 41.4 years (SD: 14.0); 57.3% were male and 93.4% had commercial health insurance. Common comorbidities observed included hypertension (24.6%), anxiety (9.5%), depression (9.3%), and autoimmune diseases (6.1%). (Table 1).
The prevalence of microvascular complications, retinopathy, neuropathy, and nephropathy was 38.6%, 38.6%, and 12.6%, respectively. The prevalence of any stage chronic kidney disease was 17.7%, of which Stage 5 CKD was 10.2% (Table 2).
The prevalence of macrovascular complications, coronary artery disease, peripheral vascular disease, congestive heart failure, and cerebrovascular disease were 13.2%, 11.4%, 6.2%, and 6.0%, respectively. Hyperlipidemia or atherosclerotic disease had the highest prevalence, affecting 55.4% of patients. Other macrovascular complications observed are reported in Table 2.
The mean annualized total all-cause costs per patient were 57,181) in 2022 USD (22,981 (SD: 2,423 (SD: 3,318, SD: 993, SD: 2,932, SD: 7,173, SD: 16,839 (SD: 13,029 (SD: 9,765 in 2022 USD ($11,034 in 2025 USD).
Fig. 1 Mean All-cause Direct Medical Costs by Care Setting, PPPY. *In 2022 USD by healthcare setting for patients with T1D and at least 1 hypoglycemia diagnosis in emergency department/hospitalization. ED Emergency department, IP Inpatient, PPPY per patient per year, T1D Type 1 diabetes, USD United States dollars
This is the first U.S claims database study examining annual total medical care costs for patients with at least 1 hospital-treated SHE specifically in pwT1D. Findings from this study highlight high rates of T1D-related complications and elevated medical care costs.
The rates of T1D-related complications among patients with at least 1 hospital-treated SHE in this study were notably higher than those reported in the literature for the broader T1D population [8, 10]. Prior literature reports the prevalence of neuropathy in the broader T1D population as 7.8–16.5% [15], whereas in this study cohort, the prevalence was two to three times higher (38.6%). Similarly, prior literature reports the prevalence of coronary artery disease as 5.7–6.5% [15] among adults with T1D, whereas a prevalence of 13.2% was observed in this study population of interest with severe hypoglycemia. Some pwT1D intentionally maintain blood glucose levels above the recommended HbA1c targets as a strategy to avoid SHEs, thereby increasing the risk for long-term complications. The multi-fold elevated rates of these micro- and macro-vascular complications are consistent with prolonged, uncontrolled hyperglycemia, which have been hypothesized to potentially impact vascular function and increase cardiovascular risk [4, 16]. It is important to note that our study cohort represents a more clinically complex subset of individuals with T1D, those who were admitted to ER or hospital to treat an SHE. These rates of complications underscore the noted comorbidity burden in this more complicated group.
Consistent with increased clinical complexity, these pwT1D with hospital-treated SHEs incurred high annual healthcare costs. The mean total all-cause annual medical costs per patient was 17,784–18,264 PPPY) [15]. Even when the cost of hospital-treated SHE ($11,034 [in 2025 USD]), which allowed identification of the patients, was removed, the total direct annual medical costs for these patients were more than double that for adult T1D population. The elevated costs are consistent with previous studies that have reported the substantial economic burden of SHEs [8, 17]. For example, Shi et al., 2021, found that patients with SHEs incur higher rates of hospitalization, ED utilization, and medication use [18]. These studies reinforce the findings of this study and further emphasize the substantial clinical and economic burden associated with SHEs.
There are key limitations with this study. First, the study was conducted during a period of early adoption of advanced diabetes technologies, such as hybrid closed-loop systems. Recent literature estimated the annual cost of advanced diabetes technologies as approximately $10,000 [19, 20]. Second, by focusing only on direct medical costs, the study underestimated the total economic burden of SHEs, which also include substantial indirect costs such as work productivity loss [15]. Third, the database included primarily commercially insured patients, limiting the generalizability of these findings to patients covered by other types of insurance. Fourth, sex-based or gender-based analyses were not performed, as the primary objective was to assess overall burden in a more complicated population, rather than to compare outcomes across demographic subgroups. Finally, given the complexity of identifying SHEs in a claims database, future research using other types of real-world data (e.g., electronic medical records) could be considered to identify T1D patients without SHEs and assess their outcomes for contextualization.
This study highlights the substantial clinical and economic burden in pwT1D who experienced hospital-treated SHEs. The high rates of clinical complications and substantial direct medical costs underscore the complexity of this subgroup of patients.
Below is the link to the electronic supplementary material.
The authors would like to acknowledge Elizabeth Langford, employee of IQVIA for her assistance with manuscript preparation. This medical writing and editorial assistance was funded by Vertex Pharmaceuticals Incorporated.
Adriana Boateng-Kuffour, Keval Chandarana, Nanxin Li, Liang Chen, Jason Gaglia, and Beth Barber were involved in the design, execution, and interpretation of results. Vamshi Ruthwik Anupindi, Michael Hull, Xiaoyu Zhou and Mitch DeKoven were involved in the design and execution of this study.
This study was funded by Vertex Pharmaceuticals Incorporated. The journal’s Rapid Service and Open Access Fees was funded by Vertex Pharmaceuticals Incorporated.
The datasets generated during and/or analyzed during the current study are not publicly available as the data used was proprietary and were used under license with IQVIA for the current study.
Adriana Boateng-Kuffour, Nanxin Li, Keval Chandarana, Liang Chen, and Beth Barber are employees of Vertex Pharmaceuticals Incorporated, and hold stocks at Vertex Pharmaceuticals Incorporated. Jason Gaglia is a consultant for Vertex Pharmaceuticals Incorporated and an employee of Joslin Diabetes Center. Vamshi Ruthwik Anupindi, Michael Hull, Xiaoyu Zhou and Mitch DeKoven were employees of IQVIA at the time this study was conducted, which received funding from Vertex Pharmaceuticals Incorporated for conducting this study. Michael Hull and Mitch DeKoven are no longer employed at IQVIA but have no new affiliations.
This study used de-identified, retrospective administrative claims data and did not involve the collection or use of identifiable personal information. As such, institutional review board (IRB) approval was not required in accordance with the Health Insurance Portability and Accountability Act (HIPAA). Necessary permissions were obtained from IQVIA to access and use the data.
The datasets generated during and/or analyzed during the current study are not publicly available as the data used was proprietary and were used under license with IQVIA for the current study.