583 - Epidemiology and Resource Utilization in Infantile Epileptic Spasm Syndrome Hospitalizations: National Inpatient Sample, 2016-2022

Publication Number: 3564.583

Avantika Singh, Medical College of Wisconsin, Milwaukee, WI, United States; Chellamani Harini, Boston Children's Hospital, Westborough, MA, United States; Erwin T. Cabacungan, Medical College of Wisconsin, Children's Wisconsin, Milwaukee, WI, United States

Background: Infantile epileptic spasm syndrome represents a rare and severe early childhood epilepsy. Despite epileptic spasms (ES) being one of the most recognizable pediatric epilepsy emergencies, national data describing its modern epidemiology and healthcare impact remain limited. Understanding national burden of hospitalizations and demographic variation of ES can help identify changing disease patterns, comorbidities, and optimize resource allocation.

Objective: To describe trends, demographic and hospital characteristics, risk factors, and outcomes of epileptic spasm hospitalizations among children aged 0-2 years using a national database.

Design/Methods: Hospitalizations for ES (ICD-10-CM G40.821-G40.824) were identified from the 2016-2022 Healthcare Cost and Utilization Project National Inpatient Sample. In this IRB-exempt study, we prespecified three age groups: < 1 year, 1 year, and 2 years. Survey-weighted analyses estimated national incidence, demographics, hospital characteristics, and risk factors. Temporal trends were assessed using survey-weighted logistic regression (Cochran-Armitage equivalent). Negative binomial regression estimated incidence rate ratios (IRR) for length of stay (LOS) and generalized linear models (GLM) evaluated total charges.

Results: The final ES cohort comprised 28,985 (9.9/10,000) discharges among children aged 0-2 from 2016-2022 (Fig.1A). Weighted ES hospitalizations increased from 8.37 (95% CI 6.73-10.01) to 10.88 (95% CI 8.80-12.97) per 10,000 discharges (p = 0.065) (Fig.1B). Age-specific trends were nonsignificant for < 1 year (p = 0.40), but significant for 1 year (OR 1.04, 95% CI 1.01-1.08, p = 0.014) and 2 years (OR 1.10, 95% CI 1.06-1.14, p < 0.001). Demographic differences were noted for race, public insurance, income quartile, and patient location. Hospital characteristics varied by bed size and region (Tables 1A & B). CNS anomalies and autosomal anomalies were independently associated with ES. Compared with < 1 year, odds of mechanical ventilation and cerebral palsy were higher for 1-2 years, and gastrostomy was more frequent at 1 year (Fig. 2). LOS was longer among survivors at 2 years (IRR 1.13, 95% CI 1.01-1.28, p = 0.037), and total charges were higher (GLM 1.18, 95% CI 1.02-1.37, p = 0.024) (Table 2).

Conclusion(s): ES hospitalizations increased nationally from 2016 to 2022, driven by rising rates at 1 and 2 years of age, highlighting the burden of this rare disease. While LOS remained stable overall, 2-year age group had longer stays among survivors and higher hospital charges, underscoring the growing healthcare impact and age-specific needs in ES management.

Fig 1A. Flow Diagram of the Final Study Cohort from HCUP NIS Database (2016 -2022); and Fig 1B. Trends of the Incidence of Epileptic Spasms Hospitalizations (Per 10,000 Discharge Records), 2016 - 2022
Fig. 1A - Illustrates the cohort selection process from an initial weighted 241 million hospital discharges to the final weighted 28,985 hospital discharges
Fig.1B - Incidence of epileptic spasms hospitals stratified by age ( < 1 year, 1 year, 2 years) and combined (0-2 years) from 2016-2022. †Temporal trends were assessed using survey-weighted logistic regression with year as an ordinal variable, equivalent to a Cochran-Armitage test for trend adjusted for the HCUP-NIS complex sampling design. There was no significant trend for <1 year (OR 1.02; 95% CI 0.98-1.06; p = 0.400), significant upward trend by 4.4% per year for 1 year (OR = 1.04; 95% CI 1.01-1.08; p = 0.014), significant upward trend by 10% per year for 2 years (OR = 1.10; 95% CI 1.06-1.14; p < 0.001), and borderline increase over time for combined 0-2 years ((OR = 1.04; 95% CI 1.00-1.07; p = 0.07).

Table 1A. Survey-Weighted Demographic Characteristics of Hospitalizations for Epileptic Spasms by Age Group; Table 1B. Survey-Weighted Hospital Characteristics, Risk Factors, and Resource Utilization for Epileptic Spasms by Age Group
Table 1A - Comparison of demographic characteristics among infants ( <1 Year) and toddlers (1-2 Years) hospitalized with epileptic spasms, presented as weighted n (%). †Comparisons across age groups were assessed using Chi-square test; significant values are shown in bold red.
Table 1B - Comparison of hospital characteristics, clinical risk factors, and resource utilization among infants ( <1 Year) and toddlers (1-2 Years) hospitalized with epileptic spasms. †Categorical variables are presented as weighted n (%) and compared across groups using Chi-square test. ††Continuous variables (Length of Stay, Total Charges) are expressed as median (IQR) and compared using the Kruskal-Wallis test. Significant values are in bold red.

Fig. 2. Forest Plot of Adjusted Odds Ratios (95% CI) for Comorbidities and Outcomes by Age Group Among Infants and Toddlers with Epileptic Spasms. Table 2. Unadjusted and Adjusted Models of Hospital Resource Utilization by Age Group Among Infants and Toddlers with Epileptic Spasms
Fig. 2 -Forest plot showing adjusted odds ratios (95% CI) comparing infants ( <1 Year) with toddlers (1 and 2 years) hospitalized for epileptic spasms. Reference age group: <1 Year._x000B_Comorbidities include the use of mechanical ventilation, tracheostomy, and gastrostomy; outcomes include death and cerebral palsy (CP). Models were adjusted for demographic, hospital, years, and clinical covariates. Significant associations were observed for: Mechanical ventilation: 1 Year (OR 2.08; 95% CI 1.56-2.77; p < 0.001) and 2 Years (OR 2.82; 95% CI 2.07-3.84; p < 0.001); Gastrostomy: 1 Year (OR 1.55; 95% CI 1.12-2.15; p = 0.009); and Cerebral palsy: 1 Year (OR 3.67; 95% CI 2.84-4.75; p < 0.001) and 2 Years (OR 5.41; 95% CI 4.15-7.06; p < 0.001). Significant p-values are shown as a blue asterisk.
Table 2 - Survey-weighted regression analyses showing unadjusted and adjusted incidence rate ratios (IRR) for length of stay (LOS) and generalized linear model (GLM) ratios for total hospital charges across age groups ( <1 year, 1 year, 2 years). Models were adjusted for demographic, hospital, years, and clinical covariates. Reference age group: < 1 Year. Significant differences were observed for survivors aged 2 years, who had a longer LOS (adjusted IRR 1.13; 95% CI 1.01-1.28; p = 0.037) and higher total charges (adjusted ratio 1.18; 95% CI 1.02-1.37; p = 0.024) compared with infants <1 Year. Values are presented as IRR or GLM ratio (95% CI); significant p-values are shown in bold red.