The state Medicaid programs included in this study covered more than 2.5 million individuals each year who were aged 17 years and under and who were continuously enrolled in fee-for-service Medicaid, adding up to a total of 10,690,434 person-years from 2000 through 2003. Sample characteristics are presented in . The number of patients with a mental disorder rose from 508,561 in 2000 to 572,701 in 2003, representing 21.2% of the studied population in 2003. The mean age among those with a mental disorder ranged from 9.5 to 9.7 years. The number of children with an ASD rose from 14,552 in 2000 to 20,099 in 2003. Although the proportion of those with an ASD was relatively small, ranging from 2.9% to 3.5% among those with a MD, it increased by 20.7% over the study period, a rate of increase higher than any of the other diagnostic groups except anxiety disorder.
Characteristics of patients with mental disorders (fee-for-service patients only)
Among children with an ASD, as shown , more than 75% were male, higher than the 62% male proportion among patients with other mental disorders (). Although children with ASD rarely had a diagnosis of bipolar disorder or substance abuse/dependence, they often had comorbid hyperactivity, mental retardation, conduct disorder or learning disorder. Children with an ASD were about half a year younger than those with other mental disorders.
Comorbid conditions of patients with an autism spectrum disorder (ASD)
As indicated in , the treated prevalence of ASDs per 10,000 covered lives in fee-for-service Medicaid ranged from 57.5 in 2000 to 74.1 in 2003, which was relatively low compared to hyperactivity, conduct disorder or learning disorder. However the treated prevalence of ASDs rose by 28.7% from 2000 to 2003, the largest increase among all the mental disorder diagnostic groups. In particular, the treated prevalence of autism as a subcategory of ASDs increased by 32.2% from 40.6 to 53.6 per 10,000 covered lives.
Treated prevalence of mental health disorders per 10,000 covered livesa
reports total health care expenditures per treated patient for ASDs and for other mental disorders in 2003 dollars. Mean total health care expenditures per treated child were $22,079 in 2000 (in 2003 dollars), with mean expenditures for autism and any other ASDs being $22,833 and $20,342, respectively. Mean expenditures for ASDs were higher than those for the other diagnostic groups except mental retardation and psychosis. The median expenditures for ASDs were a little above half of the mean, indicating that a relatively small proportion of heavy spenders had driven up mean expenditures, despite the winsoring. Median expenditures were higher for ASD patients than any other diagnostic group. The mean expenditures for ASDs increased by just 3.1% from 2000 to 2003, whereas the increase was 17% for bipolar disorder and 20% post-traumatic stress disorder.
Total health care expenditures per treated patient with a mental disordera
Health care expenditures per 10,000 covered lives for ASDs were $1,270,435 in 2000 (in 2003 dollars) and $1,686,938 in 2003 (see ). These expenditures were in the middle range, with hyperactivity, mental retardation, conduct disorder and learning disorder being relatively expensive and bipolar disorder and anxiety disorder being relatively inexpensive. ASD-related expenditures per 10,000 covered lives increased by 32.8% from 2000 to 2003, the highest rate of increase of all the diagnostic groups. In particular, health care expenditures per 10,000 covered lives for autism as a sub-category of ASDs increased 37.0%.
Total health care expenditures per 10,000 covered lives a