Prescription Drug Utilization and Associated Costs Among Children with Case-Defined Autism Spectrum Disorders

Background: Evidence suggests that children with autism spectrum disorders (ASD) have high rates of prescription drug utilization, particularly psychotropic medications used alone or in combination. Children with ASD have substantially higher costs of care than children without ASD; a large portion of excess costs could be due to prescription drugs. However, medication utilization studies in this population have been limited by parent recall, volunteer participation, or claims-based analysis to identify patients with recorded ASD diagnoses.

Objectives: The aims of this study were (1) to describe prescription drug use, and (2) to examine costs associated with prescription drug use among children with ASD.

Methods: Children were identified through the population-based South Carolina Autism and Developmental Disabilities Monitoring Network (SCADDM). All children with case-defined ASD from the two most recent surveillance years (2006 and 2007) and who were Medicaid-eligible during the surveillance year plus one year prior were included; at age 7 or 8 years for those identified in the Coastal and Pee Dee regions of the state in 2006, and age 14 or 15 years for those identified in a demographically similar sub-region in 2007. All confidentiality procedures were followed and appropriate regulatory approvals were granted. Data linkages were made using unique identifiers common to both datasets; PHI was removed following this linkage, resulting in a completely de-identified database that contained a two-year history of prescription drug utilization and associated costs. Categorical and continuous variable differences were assessed using chi-square or t tests respectively.

Results:

Of the 263 children with case-defined ASD and Medicaid information, 56% (n=147) had at least one prescription of any type filled, 40% (n=105) used psychotropic medication, and 20% (n=52) used multiple psychotropic classes during the study period. The most common combinations were attention deficit hyperactivity disorder (ADHD) medications plus an antihypertensive, antidepressant, or antipsychotic; and antidepressants plus an antipsychotic. Older children (15/16 years) were more often prescribed multiple psychotropic classes (31% versus 16%, p<.01), had a higher mean number of psychotropic prescription claims (16.3 versus 5.9, p=.02), and 2.4 times higher prescription drug costs over the study period ($2999 versus $1260, p=.05) when compared to younger children (7/8 years). Overall, children with any psychotropic medication had significantly higher mean prescription drug costs than children without psychotropic medication ($3632 versus $420, p<.0001).

Conclusions:  

The current study was able to provide a more complete and precise estimate of medication use among children with ASD by combining population-based data and Medicaid. These results confirm that psychotropic medication use alone or in combination among those with ASD is common, costly, and may increase with age.