Co-occurring mood disorders among hospitalized patients and risk for subsequent medical hospitalization.
OBJECTIVE
The objective was to determine if patients hospitalized with a primary medical diagnosis and any co-occurring serious mental illness (SMI) were more likely than patients without any co-occurring SMI diagnosis to experience a subsequent medical hospitalization.


METHODS
This was a longitudinal cohort study of 925,705 adult persons (aged 18+ years). Patients hospitalized in Washington State from 2004 to 2008 were followed through 2009 (for an average of 43 months).


RESULTS
Compared to patients hospitalized for medical conditions without co-occurring SMI, patients with co-occurring dysthymia, bipolar and major depressive disorders were at an elevated risk for long-term subsequent hospitalization. Patients in the combined co-occurring mood disorders cohort were more likely (hazard ratio=1.13; 99% confidence interval=1.10-1.16; P<.001) than patients in the reference cohort to experience a subsequent medical hospitalization. A significant interaction between substance and mood disorders that increased risk for subsequent hospitalization was also observed.


CONCLUSIONS
Hospitalized patients with co-occurring mood disorders are at high risk for repeat hospitalization for a medical reason. This high-risk population, including those with substance abuse, should be a focus of research efforts to identify and address ambulatory-care-sensitive conditions amenable to strategies that decrease complications and illness leading to subsequent hospitalizations.
College of Nursing, Washington State University, Spokane, WA, USA. kdaratha@wsu.edu
Kenn B
KB
Daratha
Celestina
C
Barbosa-Leiker
Mason
M
H Burley
Robert
R
Short
Matthew E
ME
Layton
Sterling
S
McPherson
Dennis G
DG
Dyck
Bentson H
BH
McFarland
Katherine R
KR
Tuttle
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D005260:Female; D006760:Hospitalization; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000453:epidemiology*; D018570:Risk Assessment; D014861:Washington / Q000453:epidemiology; D055815:Young Adult