For each of the study years, information was available for over 2 million hospitalizations (unweighted) representing 6.3-6.5 million hospitalizations for children in the U.S., with fewer than 0.01% of cases missing information on diagnoses. In 2000, 2003 and 2006, the weighted number of hospitalizations of children under age 18 with a mental health principal diagnosis ranged from 145,024-160,252. The percentages of hospitalizations with a mental health principal diagnosis were 15.6%, 15.2%, and 15.0% in children 10-14 in the study years 2000, 2003, and 2006, and 15.2$, 14.5% and 13.7% in children 15-17 in the same study years. For children age 5-9, hospitalizations with a mental health principal diagnosis accounted for 4.8%, 4.4% and 4.7% of pediatric hospitalizations in the three study years. For children age 1-4, the percentages were 0.2% for each year.
Of the hospitalizations with a mental health principal diagnosis, 88,276 (55%) in 2000, 92,349 (60%) in 2003, and 86,251 (59%) in 2006 had a principal diagnosis of mood disorders. The incidence of hospitalizations with mood disorders as the principal diagnosis (MHSA-CCS code 657) was 12.4/10,000 (95%CI = 12.1-12.7) in 2000, 13.0/10,000 in 2003 (95% CI = 12.8-13.3), and 12.1/10,000 (95% CI = 11.9-12.2) in 2006. The incidence of hospitalizations with any diagnosis of mood disorders was 18.9/10,000 (95%. CI = 18.5-19.2) in 2000, 20.4/10,000 in 2003 (95% CI = 20.1-20.6), and 19.6/10,000 (95% CI = 19.3-19.9) in 2006.
The CCS-MHSA system subdivides the group "Mood disorders" into two categories, "Bipolar disorders" and "Depressive disorders." At this level of classification, the incidence of hospitalizations for depressive disorders decreased from 9.1/10,000 (95% CI = 8.8-9.3) in 2000, to 8.4/10,000 (95% CI = 8.3-8.6) in 2003, and to 6.4/10,000 (95% CI = 5.5-5.8) in 2006, while the incidence of hospitalizations for bipolar disorders increased from 3.3/10,000 (95%CI = 3.2-3.5) in 2000 to 4.6/10,000 (95% CI = 4.5-4.7) in 2003 and 5.7/10,000 (95% CI = 5.5-5.8) in 2006 (Table ).
Incidence of hospitalization per 10,000 and 95% Confidence Intervals among children under 18, 2000-2006
At the most granular level, the category, "Mood disorders", includes 56 ICD-9-CM codes (Appendix 1). In 2006, the most frequent specific mood disorder diagnosis was "unspecified episodic mood disorder" (ICD-9-CM 296.90) and accounted for 11.0% of the hospitalizations for mood disorders (Table ). This was followed by depressive disorder not elsewhere classified (311) and manic-depressive not otherwise specified (296.80) which accounted for 10.3 and 8.4 percent of the hospitalizations, respectively. The eight most frequent specific diagnoses accounted for over 50% of the hospitalizations with a principal diagnosis of mood disorders.
The leading ICD-9-CM diagnoses in children hospitalized with a principal diagnosis of mood disorder as a percentage of all hospitalizations with a principal diagnosis of mood disorder, 2006
The diagnosis of mood disorder was strongly associated with suicide attempt (or self-injurious behavior). Within children with any diagnosis of mood disorder, the percentage with a suicide attempt was 11.0% in 2000, 10.2% in 2003, and 9.7% in 2006. Within children with no diagnosis of mood disorder, the percentage with a suicide attempt was 0.2%, 0.1% and 0.1% in the same study years. In 2000, children with any diagnosis of mood disorder were 73 times more likely to have a code of "suicide attempt" on their hospital record compared to children without a diagnosis of mood disorders, in 2003 they were 101 times as likely and in 2006 they were 122 times as likely.
The incidence of hospitalizations for mood disorders increased with age. In 2006, the incidence of hospitalizations with any diagnosis of mood disorders was 7.2/10,000 in children ages 5-11 and 47.1/10,000 in children ages 12-17, and the incidence of hospitalizations with principal diagnosis of mood disorders was 4.4/10,000 and 29.0/10,000, respectively. The rate was less than 1.0/10,000 in children under 4. Age specific rates show a sharp increase between age 12 and 17, and a slight decline between age 17 and 18 (Figure ). Among the hospitalizations with any diagnosis of mood disorder there were more females than males (57% female in 2006).
Pediatric hospitalizations with diagnoses of mood disorders, age specific rates/10,000 children 2006.
Over the years 2000 to 2006, an increasing proportion of hospital stays for mood disorders was paid by the government (Table ). Medicare and Medicaid were expected payers for 35% of cases in 2000, increasing to 45% in 2006, and, correspondingly, the proportion paid by private insurance decreased from 57% to 45%. Over the same period, teaching hospitals accounted for an increasingly greater proportion of the hospitalizations, from 52 to 63%. The distribution of mood disorder hospitalizations by hospital size remained fairly constant (9-10% in small hospitals, 22-24% in medium hospitals, and 68% in large hospitals over 2000-2006). Inflation-adjusted charges for hospitalization increased from $10,600 in 2000, to $13,700 in 2003, to $16,300 in 2006, accompanied by a slight increase in length of stay from 7.1 days in 2000 to 7.7 days in 2006. The aggregate charges for hospitalizations with any diagnosis of mood disorders were over $2.2 billion in 2006.
Characteristics of hospitalization among children under 18 with any mood disorder diagnosis, 2000-20061
Hospitalization rates for children with a principal diagnosis of mood disorders varied several fold by region of the country. The western region of the United States experienced the lowest pediatric hospitalization rates for mood disorders, ranging from 9.9/10,000 to 11.6/10,000 during the 2000-2006 time period (Figure ). In the same period, hospitalization rates for mood disorders ranged from 18.1/10,000 to 21.9/10,000 in the South and 19.0/10,000 to 21.2/10,000 in the Northeast. Hospitalization rates for mood disorders in children were highest in the Midwest ranging from 25.4/10,000 to 27.6/10,000 children. Rates in the Midwest, Northeast and South were more than double the rates of the West. In the Midwest, the Relative Risk of admission to a hospital with a diagnosis of mood disorder was 2.7, 2.4 and 2.5 in the three study years. In the Northeast, these same Relative Risks were 2.1, 1.6 and 2.1, and in the South, the Relative Risks were 1.8, 1.9 and 2.1. In 2006, a similar pattern was observed for hospitalizations with any mental health diagnosis as a primary diagnosis with rates of 20.1/10,000 in the Midwest, 16.6/10,000 in the Northeast, and 16.5/10,000 in the South, all, higher than the 6.4/10,000 observed in the West. Hospitalizations with any mental health diagnosis (primary or not) were 49.7/10,000 in the Midwest, 51.6/10,000 in the Northeast, 48.5/10,000 in the South and 30.7/10,000 in the West. The regional variation in hospitalizations for mood disorders contrasts with the overall rates of pediatric hospitalizations by region for 2006. The highest hospitalization rates were found in the South (1,004.4/10,000) followed by the Northeast (891.4/10,000) and West (862.1/10,000), and lowest in the Midwest (788.1/10,000).
Hospitalization rates with any diagnosis of mood disorders by region 2000-2006.
The mean age ranged from 13.9 in the South to 14.5 in the West. In 2006, the rates of hospitalizations for females and males followed the regional pattern; females and males from the Midwest had the highest rates and their counterparts from the West had the lowest rates of hospitalization with any diagnosis of mood disorder. The proportion paid by Medicare or Medicaid ranged from 31.2% in the West to 51.8% in the South, and the proportion paid by private insurance ranged from 38.3% in the South to 56.5% in the West. Mean total charges in 2006 were lowest in the Midwest ($12,260) and highest in the West ($23,980). The average length of stay was lowest in the Midwest (6.5 days) and highest in the Northeast (10.4 days).