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Part I: Overview

What are the common reasons for hospitalization, by type and diagnosis?

This report compares the following types of hospital stays for adults (18 years and over)—

Stays with at least one MHSA diagnosis: Stays related to mental health or substance abuse disorders.iii This type is further divided into these three subtypes:

  • Principal MHSA only: The principal reason for hospitalization was a MHSA disorder and no additional MHSA diagnoses were indicated on the discharge record.iv
  • Principal and secondary MHSA: The principal reason for hospitalization was a MHSA disorder and at least one additional MHSA diagnosis was indicated on the discharge record.
  • Secondary MHSA only: One or more MHSA diagnoses were listed as secondary or complicating conditions, but the principal reason for the hospital stay was not a MHSA disorder.

Stays with no MHSA diagnosis: Stays related to medical, surgical or obstetric conditions that did not have a MHSA diagnosis on the discharge record.

Common Reasons, by Type

  • In 2004, 24 percent of hospital stays for adults in U.S. community hospitals were related to MHSA disorders—almost 7.6 million hospitalizations.
  • Nearly 6 percent of adult hospital stays (about 1.9 million) had a principal MHSA diagnosis and 18 percent of adult stays (5.7 million) were primarily for a non-MHSA condition but had a secondary MHSA diagnosis.
  • Among MHSA hospital stays, nearly 25 percent had a principal MHSA diagnosis listed on the discharge record. The remaining three-fourths were for non-MHSA disorders with a secondary MHSA diagnosis.

Common Reasons, by Diagnosis

  • The most common MHSA disorders seen in hospital stays were mood disorders, substance-related disorders, delirium/dementia, anxiety disorders, and schizophrenia.
  • One out of every 10 hospital stays was related to mood disorders (over 3.3 million stays).
  • One out of every 14 hospital stays was related to substance-related disorders (2.3 million stays).
  • One out of every 20 stays was related to delirium/dementia (1.7 million stays).

iii All MHSA diagnoses were classified into 11 mutually exclusive categories. Details on the classification scheme can be found in the Methods, Glossary, and Appendix A.
iv“Principal” diagnosis is the main reason for hospitalization after evaluation during the stay. “Secondary” diagnosis is an additional, complicating condition that is present on admission or develops during the stay.


Select for Figure 1. (7 KB), Mental Health and Substance Abuse-Related Hospital Stays, by Type.

Table 2. Stays for All-Listed MHSA Diagnoses

All-Listed MHSA Diagnoses Total Number Of Hospital Stays
(in thousands)
Percentage Of All Hospital Stays
Mood disorders including bipolar disorders and depressive disorders 3,311 10.4
Substance-related disorders including drug and alcohol abuse disorders 2,253 7.1
Delirium, dementia, and amnestic and cognitive disorders 1,691 5.3
Anxiety disorders 1,153 3.6
Schizophrenia and other psychotic disorders 821 2.6
Miscellaneous mental disorders 334 1.1
Personality disorders 253 0.8
Adjustment disorders 123 0.4
Disruptive behavior disorders 51 0.2
Impulse control disorders 25 0.1
Disorders usually diagnosed in infancy, childhood, and adolescence 11 0.0

Note: “All-Listed MHSA Diagnoses” refers to all MHSA diagnoses listed on the discharge record. Patients can have more than 1 MHSA diagnosis; thus, the sum of the number and percentage of hospital stays do not match the pie chart.
“0.0” percent indicates < .05 percent.

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How Do Stays Vary by Gender and Age?

Gender

  • Women made up a disproportionate share of patients hospitalized for MHSA disorders in 2004. Although women comprised 51 percent of the U.S. adult population, they accounted for 58 percent of MHSA stays and 62 percent of non-MHSA stays. The top 5 MHSA diagnoses for women were:
    1. Mood disorders (11.1 percent)
    2. Delirium/dementia (5.5 percent)
    3. Substance-related disorders (4.1 percent)
    4. Anxiety disorders (4.0 percent)
    5. Schizophrenia (2.0 percent)
  • Men comprised 49 percent of the U.S. adult population in 2004, but they accounted for only 43 percent of MHSA stays and 38 percent of non-MHSA stays. The top 5 MHSA diagnoses for men were:
    1. Substance-related disorders (11.8 percent)
    2. Mood disorders (9.2 percent)
    3. Delirium/dementia (5.1 percent)
    4. Schizophrenia (3.4 percent)
    5. Anxiety disorders (3.1 percent)
  • Hospital stays associated with substance-related disorders were nearly three times more common among men than women.

Select for Figure 2. (11 KB), Hospital Stays and U.S. Population, by Gender.

Table 3. Stays for All-Listed MHSA Diagnoses, by Gender

All-Listed MHSA Diagnoses Female Male
Number Of All-Listed Diagnoses, In Thousands
(percentage of all gender-specific hospital stays)
Mood disorders including bipolar disorders and depressive disorders 2,169 (11.1) 1,139 (9.2)
Substance-related disorders including drug and alcohol abuse disorders 794 (4.1) 1,457 (11.8)
Delirium, dementia, and amnestic and cognitive disorders 1,063 (5.5) 628 (5.1)
Anxiety disorders 774 (4.0) 378 (3.1)
Schizophrenia and other psychotic disorders 398 (2.0) 420 (3.4)
Miscellaneous mental disorders 294 (1.5) 40 (0.3)
Personality disorders 149 (0.8) 104 (0.8)
Adjustment disorders 70 (0.4) 53 (0.4)
Disruptive behavior disorders 23 (0.1) 29 (0.2)
Impulse control disorders 9 (0.1) 16 (0.1)
Disorders usually diagnosed in infancy, childhood, and adolescence 3 (0.0) 8 (0.1)

Note: “All-Listed MHSA Diagnoses” refers to all MHSA diagnoses listed on the discharge record; patients can have more than 1 MHSA diagnosis.
“0.0” percent indicates < .05 percent.

Age

  • Overall, the mean age for adults hospitalized with any MHSA disorder was similar to that of all other patients—58 and 56 years, respectively. Hospitalizations for principal MHSA disorders (i.e., principal MHSA only plus principal and secondary MHSA) occurred more often among younger adults (mean age = 46 years); hospitalizations for only secondary MHSA disorders occurred more often among older adults (mean age = 62 years).
  • Older age groups accounted for a disproportionate share of hospital stays for MHSA disorders overall in 2004. Adults 65-79 years comprised 12 percent of the U.S. adult population, but they accounted for nearly 20 percent of MHSA hospital stays and 26 percent of non-MHSA stays.

Select for Figure 3. (8 KB), Mean Age, by Type.

  • Adults 80 and older comprised 5 percent of the U.S. adult population, yet they accounted for nearly 21 percent of MHSA hospital stays and 15 percent of non-MHSA stays.
  • In contrast, adults ages 18 to 44 comprise over half the total U.S. adult population, but they accounted for only 30 percent of MHSA hospital stays and 33 percent of hospital stays with no MHSA diagnosis.
  • While adults ages 45 to 64 represented nearly one-third (32.1 percent) of the U.S. adult population, they accounted for slightly fewer hospital stays for MHSA disorders (29.7 percent) and non-MHSA conditions (25.9 percent).

Select for Figure 4. (13 KB), Hospital Stays and U.S. Population, by Age.

  • The most common MHSA diagnosis for adults younger than age 80 was mood disorders, seen in 11 percent of stays for patients ages 18-44, 13 percent of stays for patients ages 45-64, and 8 percent of stays for patients ages 65-79.Mood disorder was seen in 8 percent of stays for patients 80 and older, second to delirium/dementia (20.6 percent) as the most common diagnosis for this age group.
  • The second most common MHSA diagnosis for adults ages 18-64 was substance-related disorders (about 10 percent).
  • Anxiety disorders were the third most common group of MHSA disorders for all age groups—ranging from about 3 percent of inpatients age 80 and older to 5 percent of inpatients ages 45-64.

Select for Table 4, Stays for All-Listed MHSA Diagnoses, by Age Group.

Distribution of Age for the Top 5 Most Common MHSA Diagnoses

  • The distribution of age varied by the top 5 most common MHSA diagnoses. Almost half of all substance-related stays were for patients ages 18 to 44 (49.0 percent), but almost all stays related to dementia/delirium were for adults age 65 and older (93.3 percent).
  • Mood and anxiety disorders affected every age group. About one-third of stays for mood or anxiety disorder involved patients 18-44, one-third of patients were 45-64 and one-third were age 65 and older.

Select for Figure 5. (6 KB), Hospital Stays Related to Mood Disorders.

Select for Figure 6. (6 KB), Hospital Stays Related to Substance-Related Disorders.

Select for Figure 7. (7 KB), Hospital Stays Related to Delirium/Dementia.

Select for Figure 8. (6 KB), Hospital Stays Related to Anxiety Disorders.

Select for Figure 9. (6 KB), Hospital Stays Related to Schizophrenia and Other Psychotic Disorders.

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How Are Patients Admitted to the Hospital?

  • In 2004, nearly 61 percent of admissions with a MHSA diagnosis were admitted through the emergency department (ED) compared to 45 percent of admissions with no MHSA diagnosis.
  • Adults with only secondary MHSA diagnoses were the most likely to be admitted through the ED (63.6 percent). They were 1.4 times more likely to be admitted through the ED than those with no MHSA diagnosis (45.0 percent) and 1.3 times more likely than those with only a principal MHSA diagnosis (50.7 percent).
  • Hospital admissions through courts or law enforcement comprised less than 1 percent of all hospitalizations, but more than 83 percent of these admissions had a principal MHSA diagnosis and an additional 6 percent had a secondary MHSA diagnosis (data not shown).

Select for Figure 10. (13 KB), Hospital Admissions, by Type.

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What Is the Mean Length of Stay?

Length of Stay, by Type

  • On average, hospital stays involving MHSA disorders were 29 percent longer than stays for non-MHSA conditions (5.8 versus 4.5 days) in 2004.
  • Adults with only a principal MHSA diagnosis stayed in the hospital an average of 8 days compared with 5 days for patients with no MHSA condition.
  • Adults with both principal and secondary MHSA diagnoses had shorter lengths of stay than those with only a principal MHSA diagnosis (6.7 versus 8.3 days).
  • Hospital stays for adults with only secondary MHSA diagnoses were 20 percent longer than adults with no MHSA diagnosis (5.4 versus 4.5 days).

Select for Figure 11. (7 KB), Length of Hospitalization, by Type.

Length of Stay, by Principal Diagnosis

  • Among patients with a principal MHSA diagnosis, those with schizophrenia had the longest length of stay—over 11 days.
  • When disorders typically diagnosed in childhood (such as pervasive development disorders and tic disorders) required hospitalization in adulthood, stays averaged about 10 days.
  • An additional three MHSA disorders had average lengths of stay of 1 week or longer—impulse control disorders (9.6 days), delirium/dementia (8.6 days), and mood disorders (7.0 days).

Table 5. Length of Stay, by Principal MHSA Diagnosis

Principal MHSA Diagnosis Mean Length of Stay
(in days)
Schizophrenia and other psychotic disorders 11.1
Disorders usually diagnosed in infancy, childhood, and adolescence 9.7
Impulse control disorders 9.6
Delirium, dementia, and amnestic and cognitive disorders 8.6
Mood disorders including bipolar disorders and depressive disorders 7.0
Disruptive behavior disorders 5.8
Personality disorders 5.6
Miscellaneous mental disorders 3.6
Substance-related disorders including drug and alcohol abuse disorders 4.6
Anxiety disorders 3.8
Adjustment disorders 3.3

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How Much Do Hospital Stays Cost?

Per-Stay and Per-Day Cost, by Type

  • The mean total cost for a hospital stay with any MHSA diagnosis ($7,800) was 14 percent lower than for stays with no MHSA diagnosis ($8,900). The mean cost per day for MHSA hospitalizations was 42 percent lower than for non-MHSA hospital stays—$1,600 per day compared with $2,300 per day—indicating that MHSA stays were less resource intensive.
  • The mean total cost for a hospital stay with only a principal MHSA diagnosis was 39 percent lower than non-MHSA stays ($6,400 versus $8,900), and costs per day were 171 percent lower ($900 versus $2,300).
  • Stays that involved principal and secondary MHSA diagnoses were the least expensive ($5,000), but the cost per day ($900) was identical to stays for principal MHSA diagnoses only.
  • The costs of stays with only secondary MHSA diagnoses were slightly less than stays with no MHSA diagnosis ($8,500 versus $8,900).

Select for Figure 12. (10 KB), Cost per Stay and Cost per Day of Hospitalization, by Type.

Total Aggregate and Per-Stay Cost, by Principal Diagnosis

  • In 2004, hospitalizations principally for MHSA disorders cost a total of $10.2 billion.
  • Hospitalizations for the 5 most common principal MHSA diagnoses—mood disorders, schizophrenia, substance-related disorders, dementia/delirium, and anxiety disorders—cost $9.9 billion nationally in 2004.
  • The most common principal MHSA diagnosis—mood disorders—also had the highest aggregate inpatient hospital costs of all MHSA diagnoses at $3.4 billion nationally in 2004.
  • On a per stay basis, schizophrenia was the most expensive of the common principal MHSA diagnoses to treat at $8,000 per stay.
  • Disorders of childhood are rarely recorded as the principal diagnoses in adults, accounting for only 773 stays in 2004 (Go to Appendix B). When hospitalization did occur, stays were expensive. The mean cost per stay for disorders of childhood in adults was $7,200, almost as high as that for schizophrenia.

Table 6. Total Aggregate and Per-Stay Cost, by Principal MHSA Diagnosis

Principal MHSA Diagnosis Aggregate Total Costs Mean Total Cost per Stay
Mood disorders including bipolar disorders and depressive disorders $3,438,589,800 $4,800
Schizophrenia and other psychotic disorders $3,316,145,400 $8,000
Substance-related disorders including drug and alcohol abuse disorders $2,006,342,800 $4,300
Delirium, dementia, and amnestic and cognitive disorders $974,618,500 $6,700
Miscellaneous mental disorders $164,157,600 $3,700
Anxiety disorders $137,655,800 $3,500
Adjustment disorders $100,878,900 $2,700
Impulse control disorders $54,937,100 $7,200
Personality disorders $19,700,600 $4,500
Disorders usually diagnosed in infancy, childhood, and adolescence $5,544,500 $7,200
Disruptive behavior disorders $4,637,800 $4,400

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Who Is Billed for Hospital Stays?

  • About 33 percent of all uninsured stays, 29 percent of Medicaid stays, and 26 percent of Medicare stays were related to MHSA disorders. This compares to about 16 percent of privately insured stays.
  • Roughly 12 percent of uninsured stays and 12 percent of Medicaid stays were for principal MHSA diagnoses (i.e., principal MHSA only plus principal and secondary MHSA). On the other hand, only about 4 percent of Medicare and privately insured stays were principally for MHSA diagnoses.
  • Focusing on those stays with only secondary MHSA diagnoses, nearly twice as many hospital stays were billed to Medicare or were considered uninsured than were billed to private insurance (about 21 percent versus 12 percent).

Select for Figure 13. (7 KB), Uninsured or Self-Pay Hospital Stays.

Select for Figure 14. (7 KB), Hospital Stays Billed to Medicaid.

Select for Figure 15. (7 KB), Hospital Stays Billed to Medicare.

Select for Figure 16. (7 KB), Hospital Stays Billed to Private Insurance.

Expected Primary Payer, by Type

  • Over 66 percent of adult hospital stays with MHSA diagnoses were billed to the government—about 18 percent to Medicaid, a joint State and Federal Government program, and 49 percent to the Federal Medicare program. In comparison, 56 percent of hospital stays with no MHSA diagnosis were billed to the government.
  • Adults with MHSA diagnoses were 36 percent more likely to be uninsured than those without MHSA diagnoses. Nearly 8 percent of MHSA stays were uninsured compared with about 5 percent of stays without MHSA diagnoses.
  • Patients with both principal and secondary MHSA diagnoses were the most likely to be uninsured or require self-pay—nearly 13 percent compared with 5 percent for patients with no MHSA diagnosis.
  • Only about 23 percent of stays with MHSA diagnoses were billed to private health insurance compared with about 37 percent of stays with no MHSA diagnosis.
  • Between 30 and 37 percent of hospital stays with principal MHSA diagnoses were billed to Medicare and about 22 percent were billed to private insurers.
  • About 54 percent of stays with only secondary MHSA diagnoses were billed to Medicare, compared with 43 percent of non-MHSA stays.

Select for Figure 17. (15 KB), Expected Primary Payer, by Type.

Expected Primary Payer, by Principal Diagnosis

  • The majority of hospital stays for 2 of the 4 most frequent MSHA diagnoses—schizophrenia and delirium/dementia—were billed to government payers. Over 78 percent of hospital stays for schizophrenia were billed to the government (35.0 percent to Medicaid and 43.5 percent billed to Medicare). Similarly, more than 90 percent of hospital stays for delirium/dementia were billed to the government (3.6 percent to Medicaid and 86.1 percent to Medicare). This most likely was because schizophrenia is a qualifying disorder for Medicaid and delirium/dementia is more frequent among the elderly who are covered by Medicare.
  • In contrast, 53 percent of hospital stays for mood disorders and 52 percent of stays for substance-related disorders were billed to government payers.
  • About 1 in 5 hospital stays principally for adjustment disorders and substance-related disorders was uninsured. About 1 in 10 stays principally for anxiety disorders, personality disorders, mood disorders, and impulse control disorders was uninsured.
  • The only MHSA diagnoses for which private insurers covered more than other payers were mood, anxiety, and adjustment disorders.

Table 7. Expected Primary Payer, by Principal MHSA Diagnosis

Principal MHSA Diagnosis Expected Primary Payer
Uninsured Or
Self-Pay's Share
Medicaid's Share Medicare's Share Private Insurer's Share
Number of Hospital Stays, in Thousands
(percentage of disorder-specific hospital stays)
Mood disorders including bipolar disorders and depressive disorders 76 (10.8) 174 (24.7) 197 (27.9) 217 (30.8)
Substance-related disorders including drug and alcohol abuse disorders 96 (20.5) 170 (36.1) 74 (15.7) 109 (23.2)
Schizophrenia and other psychotic disorders 24 (5.9) 144 (35.0) 178 (43.5) 39 (9.6)
Delirium, dementia, and amnestic and cognitive disorders 2 (1.5) 5 (3.6) 125 (86.1) 11 (7.4)
Miscellaneous mental disorders 3 (7.4) 19 (43.7) 6 (13.2) 14 (31.9)
Anxiety disorders 5 (13.8) 7 (18.0) 12 (30.4) 13 (33.1)
Adjustment disorders 8 (22.6) 9 (22.8) 5 (12.9) 12 (32.6)
Impulse control disorders 1 (10.5) 3 (36.8) 2 (31.7) 1 (14.6)
Personality disorders 1 (13.7) 1 (30.1) 1 (28.0) 1 (20.0)
Disruptive behavior disorders * < 1 (33.0) < 1 (28.9) < 1 (26.1)
Disorders usually diagnosed in infancy, childhood, and adolescence * < 1 (36.5) < 1 (34.3) < 1 (24.6)

Note: Percentages represent row percents. Other insurance coverage is excluded; thus, the sum of row percentages does not equal 100. Statistics based on estimates with a relative standard error (standard error/weighted estimate) greater than 0.30 or with standard error = 0 are not reliable. These statistics are suppressed and are designated with an asterisk (*).

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Where Do Patients Go After They Are Discharged?

  • In 2004, about 60 percent of discharges for adults with any MHSA diagnosis were routine; that is, they were discharged to their homes. In contrast, 73 percent of adults with no MHSA diagnosis had routine discharges.
  • Adults with MHSA disorders were more likely to be discharged to a non-acute care facility (including psychiatric facilities, nursing homes, and rehabilitation centers) compared with those with no MHSA disorder. About 16 percent of hospital stays for principal MHSA diagnoses (i.e., principal MHSA only or principal and secondary MHSA) resulted in a transfer to a non-acute care health facility, while over 27 percent of hospital stays for those with only secondary MHSA diagnoses ended with such a transfer. This is primarily attributable to the larger proportion of elderly patients with dementia as secondary diagnoses (Go to Appendix C).
  • Home health care was a more common followup to stays for those with non-MHSA principal diagnoses—10 percent of those with no MHSA diagnosis and 11 percent of those with only secondary MHSA diagnoses were discharged to home health care. In contrast, only 2 percent of hospital stays for principal MHSA diagnoses were discharged to home health care.
  • Adults with a principal MHSA diagnosis (i.e., principal MHSA only or principal and secondary MHSA) were 5 to 8 times more likely to leave the hospital against medical advice than those without MHSA diagnoses. They were also 2 to 3 times more likely to leave the hospital against medical advice than those with only secondary MHSA diagnoses.
  • Adults with principal MHSA diagnoses were less likely to die in the hospital than those with non-MHSA principal diagnoses (<1 percent versus 2.6 percent).

Select for Figure 18. (10 KB), Discharge Status, by Type.

Select for Figure 19. (9 KB), Discharge Status Other Than “Home,” by Type.

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What Percentage of Hospital Resource Use Is Attributable to MHSA Disorders?

  • About 24 percent of all adult hospital stays, 29 percent of all days in the hospital, and 22 percent of total hospital costs were attributable to adults with a MHSA disorder in 2004.
  • Hospitalization for principal MHSA diagnoses (i.e., principal MHSA only plus principal and secondary MHSA) accounted for 6 percent of all adult stays, 9 percent of total days, and 4 percent of total hospital costs, pointing to the relatively low resource intensity of MHSA care in community hospitals.
  • Care for adults with only secondary MHSA diagnoses accounted for roughly 18 percent of hospital stays and total hospital costs and 20 percent of all days in the hospital.

Select for Figure 20. (11 KB), Total Hospital Resource Use.

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