substance use and five-year survival in washington state mental hospitals

SUBSTANCE USE AND FIVE-YEAR SURVIVALIN WASHINGTON STATE MENTAL HOSPITALS

Charles Maynard, Gary B. Cox, Judy Hall, Antoinette Krupski,and Kenneth D. Stark

ABSTRACT: This report combines five-year survival and cause of death in individualsdischarged from Washington State mental hospitals with (1) mental illness only, (2) co-occurring mental illness and substance use disorder, or (3) substance use disorder only.Five-year survival was similar in the three groups, although after adjusting for age, individ-uals with co-occurring disorders or substance use disorder were almost 50% more likelyto die than those with mental illness only. Persons with these conditions need treatmentto prevent premature death and medical conditions directly related to substance use dis-order.

KEY WORDS: cause of death; co-occurring disorders; state mental hospitals; survival.

Persons with serious mental illness die prematurely and are more likelyto succumb from injuries associated with psychotropic and other medica-tions (Dembling, Chen, & Vachon 1999). There is also strong evidencethat individuals with co-occurring mental illness and substance use disor-der have higher mortality rates than the general population. Individualsdischarged from residential treatment in Washington State with co-occurring disorders had an age-adjusted death rate 1.7 times greater thanthe general population (Maynard, Cox, Krupski, & Stark, 1999a). Forindividuals who had substance use disorder and were discharged in Wash-ington State, the age-adjusted death rate was over four times greater than

Charles Maynard, Ph.D., is a Research Associate Professor in the Department of Health Services atthe University of Washington, and an Investigator for Health Services Research and Development atthe Department of Veterans Affairs in Seattle, WA. Gary B. Cox, Ph.D., is a Senior Research Scientistfor the Alcohol and Drug Abuse Institute at the University of Washington, Seattle, WA. Judy Hall,Ph.D., is a Research Director in the Mental Health Division at Washington State Department ofSocial and Health Services, Olympia, WA. Antionette Krupski, Ph.D., is a Research Director in theDivision of Alcohol and Substance Abuse at Washington State Department of Social and Health Ser-vices, Olympia, WA. Kenneth D. Stark, M.B.A., M.E.D., is the Director of the Division of Alcohol andSubstance Abuse at the Washington State Department of Social and Health Services, Olympia, WA.Address for correspondence: Charles Maynard, Ph.D., 1107 NE 45th, Room 120, Seattle, WA

98105. E-mail: [email protected].

Administration and Policy in Mental Health, Vol. 31, No. 4, March 2004 (� 2004)

339 � 2004 Human Sciences Press, Inc.

that for the general population (Maynard, Cox, Krupski, & Stark, 2000).The purpose of this report is to examine five-year survival and cause ofdeath in individuals discharged from Washington State mental hospitals(Semke, Kamara, Hendryx, & Stegner 2001). Specifically, we comparesurvival and cause of death in individuals with (1) mental illness only, (2)co-occurring mental illness and substance use disorder, or (3) substanceuse disorder only.

METHODS

Study Population

This study linked computerized state hospital discharge records fromthe Washington State Mental Health Division (1996), Medicaid diagnosticdata from the Washington State Medical Assistance Administration(1996), and death records from the Washington State Department ofHealth (1996–2001). Included in this study are individuals who were18 years and older, and were discharged from Washington State mentalhospitals in the year 1996 (n ¼ 2416). Using ICD-9 diagnosis codes, weexcluded individuals with a discharge diagnosis of senility (code 290),transient organic psychosis (code 293), other organic psychoses (code294), mental retardation (codes 316–319), or developmental delays (code315), resulting in 2041 individuals available for analysis.

Persons with serious mental illness die prematurely and are more likely tosuccumb from injuries associated with psychotropic and other medications.

Study Variables

Demographic variables including age, gender, and race were obtainedfrom state hospital discharge records, as was the type of hospitalization(forensic versus non-forensic) and days hospitalized in 1996. Mental ill-ness and substance use disorder were defined with a series of ICD-9codes indicative of mental illness and/or alcohol or drug abuse ordependence, as well as medical conditions related to substance use disor-der (Table 1). Since state hospital discharge records contained only onediagnostic variable, it was not possible to identify individuals withco-occurring mental illness and substance use disorder.However, with diagnostic information from both Medicaid utilization

records and state hospital discharge records for 1996, individuals wereclassified as having mental illness only (n ¼ 1531), co-occurring disorders

340 Administration and Policy in Mental Health

(n ¼ 238), or substance use disorder only (n ¼ 182). The mental illnessonly group had one or more diagnoses listed under major mental illness,minor mental illness, or other mental conditions in Table 1, and hadnone of the conditions listed under substance use disorder. Theco-occurring group had one or more diagnoses from the three mentalillness categories and one or more from the substance use disorder cate-gory. The substance use disorder only group had no diagnoses from themental illness categories, and had one or more from the substance usedisorder category. In order for an individual to be classified as having

TABLE 1ICD-9 Diagnosis Codes for Mental Illness and Substance Use Disorder

Category Diagnosis Codes

Major mental illnessSchizophrenia 295Major depression 296.2, 296.3Other affective psychoses 296.0, 296.1, 296.4–296.9Other psychoses 297, 298, 299

Minor mental illnessStress and adjustment disorders 308, 309Personality disorders 301, excluding 301.13Childhood disorders 307, 312–314Other mood disordersand anxiety

300, 301.13, 311

Other mental disorders 302, 306, 310, 648.41–684.49Other mental conditionsSenility 290Transient organic psychoses 293Other organic psychoses 294Developmental delays 315Mental retardation 316–319

Substance use disorderAlcoholic psychoses 291Alcohol dependence/nondependent abuse

303, 305.0

Drug psychoses 292Drug dependence/nondependent abuse

304, 305.2–305.9

Other alcohol and drugrelated disordersand conditions

265.2, 357.5, 357.6, 425.5, 535.3,571.0–571.3, 648.3, 655.4, 655.5,760.7, 779.5, 962.0, 965.0,967–969, 977.0, 977.3, 980

341C. Maynard, G. B. Cox, J. Hall, A. Krupski, and K. D. Stark

co-occurring mental illness and substance use disorder, he or she had tohave diagnostic information from both a state hospital and Medicaidrecords. In the mental illness only group, 39% did not have Medicaidrecords, and in the substance use disorder only group, 70% did not haveMedicaid records.The underlying cause of death, as well as post discharge vital status,

was obtained from Washington State death records for the years 1996–2001. The underlying cause of death was classified as (1) injury/accident,such as homicide, suicide, or overdose; (2) illness related to substanceuse disorder, including hepatitis or liver failure; or (3) other, includingcardiovascular, cancer, diabetes, and other conditions. For the years1996–2000, ICD-9 codes were used, but for 2001, underlying cause ofdeath was reported with ICD-10 codes.

Statistical Methods

Baseline characteristics were compared with the chi-square statistic forcategorical variables and the student’s t-test for continuous ones. Thenon-parametric Kruskal–Wallis test was employed to compare the numberof days hospitalized across the three groups. The log rank test comparedsurvival for the three groups, and stepwise Cox proportional hazardsregression was used to identify predictors of survival. Variables listed inTable 2, as well as the three-part diagnostic category and an indicator forsubstance use disorder diagnosis, were used in multivariate analysis. Sta-tistically significant predictors (p < .05) entered the model in a stepwisemanner.

The risk of death after discharge was almost 50% higher in those with asubstance use disorder as opposed to mental illness only.

RESULTS

Most individuals were discharged with mental illness only, withco-occurring and substance use disorder comprising 16% and 9%, respec-tively, of the study population (Table 2). Individuals with mental illnessonly were older than their counterparts in the other two groups. How-ever, those with substance use disorder only were predominantly male,had a much higher proportion of forensic admissions, and were hospital-ized fewer days than individuals in the other two groups. All three groupswere predominantly white, although there was a higher proportion with


unknown race in the substance use disorder only group. All differencesin Table 2 were highly statistically significant (p < .0001).Unadjusted five-year survival was similar in the three groups. It was

90% in mental illness only, 93% in co-occurring disorders, and 87% insubstance use disorders only (p ¼ .37 by Log Rank statistic). In stepwiseCox regression analysis, age (p < .0001) was the first variable to enter,and substance use disorder diagnosis (p ¼ .024) was the second. All othervariables were not statistically significant. For each 10-year increase inage, the hazard of death went up by 95% (hazard ratio ¼ 1.95, 95% con-fidence interval ¼ 1.79–2.09). After adjusting for age, those with a sub-stance use disorder diagnosis had a 44% higher risk of death (hazardratio ¼ 1.44, 95% confidence interval ¼ 1.05–1.98).There were 214 deaths in all three groups with 162 (76%) in mental

illness only, 29 (14%) in co-occurring disorders, and 23 (11%) in sub-stance use disorder only. The median age at death was 57.5 years in themental illness only group, and 55.0 in the substance use disorder grouponly. Significantly, it was only 41.0 years in individuals withco-occurring disorders. This finding is related to differences in theunderlying causes of death, as reported on the state death certificate(Figure 1). Injury or accident was the underlying cause of death in about

TABLE 2Baseline Characteristics

VariableMental Illness

Only Co-occurring

SubstanceUse Disorder

Only

N 1531(75%) 328 (16%) 182 (9%)Age (years) 41 ± 14 35 ± 11 36 ± 14Women 37% 35% 16%RaceCaucasian 77% 85% 59%Black 7% 7% 8%Native 1% 4% 8%Asian 3% 1% <1%Hispanic 2% 1% 3%Other 2% 2% 5%Unknown 8% 0% 17%

Forensic admission 33% 45% 84%

Median dayshospitalized in 1996

67.0 30.0 11.5

Note. All comparisons p < .0001.


one-quarter of deaths in the mental illness only and substance use disor-der only groups, but accounted for over half of deaths in co-occurringdisorders, whose members died at a much younger age. In the groupwith mental illness only, 1% of deaths were due to illnesses related todrug or alcohol disorders, whereas in the co-occurring and substance usedisorder, 21% and 26%, respectively, were due to these illnesses.

Many discharged from state hospitals die at an earlier age than the gen-eral population and require treatment to prevent premature death.

CONCLUSIONS

In 1996, 25% of persons discharged from Washington State mental hos-pitals had co-occurring mental illness and substance use disorder, or sub-stance use disorder only. The risk of death after discharge was almost 50%higher in those with substance use disorder as opposed to mental illnessonly, as indicated by the the younger median age of the former group.These results suggest that persons who are discharged from state mentalhospitals with co-occurring disorders or substance use disorder only needtargeted treatment to prevent premature death from injury, or medicalconditions directly related to substance use disorder. In addition to medicalconditions attributable to substance use disorders, attention should be paidto smoking, which is associated with substance use, and may contribute topremature mortality in the form of cardiovascular and respiratory disease.

0

10

20

30

40

50

60

Mental illnessonly

Co-occurring Substance usedisorder

Per

cent

Injury/accident

Alcohol-drug relatedconditionOther

FIGURE 1Distribution of Cause of Death in Mental Illness Only, Co-occurring

Disorders, and Substance Use Disorder Only


This study was limited by having only one diagnostic variable in thestate hospital discharge database, necessitating the use of Medicaidrecords to create the diagnostic classification used. Over 70% of the sub-stance use disorder only group did not have Medicaid records in 1996.Consequently, these individuals may have had mental illness as well. How-ever, these individuals were different from those with mental illness andco-occurring disorders in that they were less likely to be female, morelikely to be hospitalized for forensic purposes, and had fewer days of hos-pitalization in 1996. Similarly, 40% of the mental illness group did nothave Medicaid records in 1996, and it is possible that some of them didindeed have co-occurring disorders. Nevertheless, the mental illnessgroup was older, and among those who died, only 1% did so from drugor alcohol-related illnesses, lending some support to the classificationused in this paper. In addition, this diagnostic classification is subject topotential errors when assigning ICD-9 diagnostic codes for the mentaland substance use disorders examined in this study. It is beyond thescope of this study to assess the extent of these potential errors.This study included individuals with serious mental illness and/or sub-

stance use disorder, serious in the sense that they were admitted to one oftwo state mental hospitals in Washington State. Among those individualsdischarged from these institutions in 1996, a substance use disorder diag-nosis increased the risk of death, as indicated by the younger median ageof this group. Particularly disturbing was the fact that these individualsdied in their early forties, predominantly from injury or accidents, or frommedical conditions directly related to their addictions. Despite potentialbias in the diagnostic classification employed, there is good evidence forincreased risk of premature death in individuals with cooccurring or sub-stance use disorder only. While many individuals discharged from statehospitals die at an earlier age than the general population and requiretreatment to prevent premature death, it appears that those with substanceuse disorder are in particular need of such treatment.

REFERENCES

Dembling, D.P., Chen, D.T., & Vachon, L. (1999). Life expectancy and causes of death in a popula-tion treated with serious mental illness. Psychiatric Services, 50, 1036–1042.

Maynard, C., Cox, G.B., Krupski, A., & Stark, K. (1999a). Utilization of services for mentally ill chemi-cally abusing patients discharged from residential treatment. The Journal of Behavioral Health Servicesand Research, 26, 219–228.

Maynard, C., Cox, G.B., Krupski, A., & Stark, K. (2000). Utilization of services by persons dischargedfrom involuntary chemical dependency treatment. Journal of Addictive Diseases, 19, 83–93.

Semke, J., Kamara, S., Hendryx, M., & Stegner, B. (2001). State mental hospitals in Washington Statein an era of policy change. Administration and Policy in Mental Health, 29, 51–65.


substance use and five-year survival in washington state mental hospitals

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