BACKGROUND

1. AUTISM-RELATED HOSPITALIZATIONS: ESTIMATES FROM 2006 HEALTH CARE COST AND UTILIZATION PROJECT KIDS' INPATIENT DATABASE Khanna R,Madhavan SS School of Pharmacy, West Virginia University, Morgantown, WV, USA Partial funding support provided by: AHRQ P20 HS 01593 BACKGROUND RESULTS METHODS (- cont.) Autism spectrum disorders (ASDs) are a set of neurodevelopmental disabilities that are characterized by deficiencies in three core domains: social interaction, communication/language skills, and behavior development. Over the past two decades, there has been a significant increase in the prevalence and incidence of ASDs in the United States (US). It is estimated that there are roughly 560,000 individuals in the age group up to 21 years with ASD in the US currently. The increasing prevalence of ASD in the US has been accompanied by an increase in the healthcare burden and costs associated with the disorder. The average lifetime societal cost of caring for an individual with autism in the US is estimated to be roughly $3.2 million, with costs from lost productivity and adult care constituting the largest component. National estimates of the effect of autism on inpatient hospital services among children in the US are not known. The burden of autism in terms of hospitalizations among children in the US has not been previously studied. Data Analyses • Given the complex sampling design of KID, analyses were conducted using SAS 9.1®. • All results are reported as national estimates (unless otherwise specified) using the appropriate sampling weights. • Distribution of autism-related hospitalizations is reported by demographic and hospital characteristics. • Rates for autism-related hospitalizations were calculated by different demographic and hospital characteristics and determined by dividing the number (weighted) of hospitalizations associated with autism with the total number (weighted) of hospitalizations in each category. • Weighted proportions and 95% confidence intervals (CIs) were generated using PROC SURVEYFREQ. • Means and corresponding standard errors for continuous variables (length of stay, charges) were generated using PROC SURVEYMEANS. • Significant associations/differences were determined using the Chi-square test for categorical variables and the t-test for means of continuous variables. • Logistic regression analysis (using PROC SURVEYLOGISTIC) was conducted to determine the factors associated with hospitalizations for autism. • Table II presents the odds ratio from logistic regression model describing the factors associated with hospitalizations with autism diagnosis among hospitalized children. • Hospitalizations for males were more likely to involve autism than those for females (AOR=6.89 (5.75, 8.26). • Admissions for children in the age group ≤4 years were less common for autism than children in the age group 15-20 years (AOR=0.03 (0.02, 0.04). • Table III shows the effect of various patient demographic and hospital characteristics on length of stay and charges for autism-related hospitalizations. • The average length of stay was higher among males ,children in the age group 5-9 years, and where the primary payer was government. • In terms of hospital characteristics, the average length of stay and charges for hospitalizations with a primary diagnosis of autism were higher among hospitals in lower income ZIP code and those in the northeast region of the country. • Roughly 12% of the hospitalizations with a primary diagnosis of autism documented the use of psychological and psychiatric evaluation and therapy (Table IV). • Most (89.5%) hospitalizations for autism results in routine discharges to home (Table V). Table 1 describes the result of comparison of patient demographic and hospital characteristics among hospitalizations with versus without a primary diagnosis of autism . Of the 3,131,324 pediatric discharges (unweighted) listed in 2006 HCUP KID, 1,456 were autism-related. Males accounted for 82.4% of autism-related hospitalizations as compared to 47.3% for non-autism related hospitalizations (p<0.001). Children ≤4 years of age accounted for only 5.3% of autism-related hospitalizations in comparison to >70% for non-autism related hospitalizations (p<0.001). Compared with non-autism hospitalizations, the average length of stay was higher for hospitalizations among children with autism (3.6 versus 13.6, p<0.001). The average hospital charge per hospitalization was also higher among children with autism than those without autism ($24,042 versus $13,017, p<0.001). Figure 1 depicts the rate of hospitalizations with a primary diagnosis of autism by patient demographic and hospital characteristics. Rates were higher among males and those in the age group 10-14 years. Table I. Comparison of patient demographic and hospital characteristics among hospitalizations with and without a primary diagnosis of autism. Figure 1. Rates of hospitalizations (per 10,000 admissions) with a primary diagnosis of autism by patient demographic and hospital characteristics. Table III. Average length of stay and charges by patient demographic and hospital characteristics for hospitalizations with a primary diagnosis of autism. OBJECTIVES To determine the rates of autism-related hospitalizations among individuals ≤20 years of age in the US. To determine the demographics and cost of hospitalizations associated with autism. CONCLUSIONS Autism-related hospitalizations have a significant economic impact on society. Consistent with the prevalence patterns of autism, a majority of hospitalizations occurred among males. In addition, the average length of stay and charges were higher among males. A large majority of hospitalizations with a diagnosis of autism resulted in patient being discharged to home. Figure 1a. Rates of hospitalization by gender. METHODS Data Source • The 2006 Healthcare Cost and Utilization Project (HCUP) Kids’ Inpatient Database (KID) was used for the purpose of the study. • Sponsored by the Agency for Healthcare Research and Quality (AHRQ), the KID is the only dataset designed specifically to assess the use of inpatient services among children in the US. • The target universe includes discharges for children (≤20 years) from community, non-rehabilitation hospitals in the US. • Discharges from academic medical centers, short-term general, and specialty hospitals including children’s hospitals are included in the dataset. • However, discharges from federal hospitals (Department of Defense, Indian Health Services, and Veterans Administrations), long-term care hospitals, psychiatric hospitals, and rehabilitation treatment facilities and hospitals are not included in the dataset. • The KID contains charge information on all patients, regardless of payer, including persons covered by private insurance, Medicaid, Medicare, and the uninsured. • The database includes information concerning patient demographics, diagnosis codes, procedure codes, admission and discharge status, payment status, length of stay, total charges, and hospital characteristics. • The 2006 KID sample was drawn from 3,739 hospitals spread across 38 states, and included 3,131,324 unweighted pediatric discharges and 7,558,812 weighted pediatric discharges. Study Sample • Hospitalizations with a primary International Classification of Diseases, Ninth Revision [ICD-9-CM] code of 299.XX were classified as autism-related. • Analysis was conducted for all children ≤20 years of age. Figure 1b. Rates of hospitalization by age group. LIMITATIONS The study only includes hospitalizations where the primary diagnosis was listed as autism, with secondary diagnosis of autism not being considered in the analyses. Due to lack of patient identifiers, we could not determine whether all hospitalizations with a primary diagnosis of autism were unique or not. Therefore, some children could have been represented more than once in the study sample. Table IV. Most common procedures performed for hospitalizations with a primary diagnosis of autism. Figure 1c. Rates of hospitalization by payer. Table II. Logistic regression model for hospitalizations with a primary diagnosis of autism. Table V. Discharge disposition for hospitalizations with a primary diagnosis of autism. Figure 1d. Rates of hospitalization by ZIP income quartile. REFERENCES HCUP: Design of the HCUP Kids Inpatient Database (KID), 2000. Rockville, MD , Agency for Health Care Research and Quality; 2003. Fombonne E. Epidemiological surveys of autism and other pervasive developmental disorders: an update. J Autism Dev Disord 2003;33:365-382. Centers for Disease Control and Prevention. (2007). Autism Information Center. Accessed September 2, 2007, from http://www.cdc.gov/ncbddd/autism/faq_prevalence.htm Ganz ML. The costs of autism. In: Moldin SO, Rubenstein JLR, eds. UnderstandingAutism: From Basic Neuroscience to Treatment. 2006 Boca Raton, Fla: Taylor and Francis Group. Newschaffer CJ, Curran LK. Autism: an emerging public health problem. Public Health Rep 2003;118:393-399. Figure 1e. Rates of hospitalization by region of hospital.