Acute Psychiatric Inpatient Care for People With a Dual Diagnosis: Patient Profiles and Lengths of Stay

Philip Burge, MSW, RSW¹, Hélène Ouellette-Kuntz, BScN, RN, MSc², Haider Saeed, BA, MSc³, Bruce McCreary, MD, FRCPC⁴, Dana Paquette, BA, MSc⁵, Franklin Sim, MD, FRCPC⁶

Objective: This study describes characteristics of psychiatry inpatients with developmental disabilities (DD) and their admissions to psychiatry wards in 2 acute care hospitals. It also compares differences in lengths of stay between admissions of this group with a comparison sample of inpatient admissions without DD.

Method: A retrospective chart review was conducted on all individuals with DD who were psychiatric inpatients at 2 Kingston, Ontario, general hospitals, within a 4-year period (1994 to 1998). A comparison sample of admissions of patients without DD was chosen. Frequency tables were used to describe the inpatients with DD and to describe the 2 samples of admissions. Nonparametric statistics were used to compare the median length of stay between the 2 samples. Associations between length of stay and other covariates were explored within the sample of patient admissions with DD.

Results: The 62 individuals with DD had 101 admissions over the study period. Suicidal ideation was the most common admission reason (46%), and mood disorder was the most common discharge diagnosis (29%). The median length of stay for patients with DD was 8 days, which did not differ meaningfully from the comparison sample. Variables that were significantly associated with length of stay among individuals with DD included sex, referral source, and diagnosis.

Conclusions: When individuals with DD are psychiatric inpatients, their length of stay is affected by some factors that have been identified in previous studies not specific to DD (for example, referral source and diagnosis). Our finding that male patients with DD have longer lengths of stay than do female patients in the same sample has not been reported in previous research.

Clinical Implications

Contrary to what is commonly thought, this study did not find that individuals with developmental disabilities (DD) have longer admissions.
Given the policy directions to depopulate residential institutions for individuals with DD and to downsize provincial psychiatric hospitals, the study results provide a baseline to monitor policy and program decisions impacting people with a dual diagnosis.
Our extensive study, now under way, will shed more light on the interplay between age, disposition, and DD as factors relevant to length of stay for psychiatric inpatient care.

Limitations

The sample size of this preliminary study did not allow us to explore fully several relations between DD and length of stay.
Many potentially relevant factors associated with length of stay could not be investigated due to the retrospective nature of the study.
The study was confined to 1 urban community in Ontario, so its findings may not be generalizable to other jurisdictions.

Key Words: dual diagnosis, length of stay, admissions, developmental disabilities, mental retardation, acute care

Résumé: Soins psychiatriques actifs des patients hospitalisés présentant un diagnostic mixte : profils des patients et durées de séjour

The DSM-IV definition of mental retardation (MR)—known as developmental disability (DD) in Ontario—specifies the existence of “significantly subaverage intellectual functioning” (that is, an IQ of approximately 70 or lower); adaptive functioning deficits or impairments; and onset before age 18 years (1). The term “dual diagnosis” refers to individuals with DD and an additional mental disorder. In a systematic literature review, Yu and Atkinson concluded that 38% of people with DD also had another mental disorder (2), which is twice as high as the 1-year prevalence of mental disorders in the general Ontario population (19%) (3).

The prevalence of additional mental disorders among individuals with DD living in regional institutions has been found to be roughly 60% (4,5). Further, studies have confirmed a high use of psychiatric services among former residents of institutions (6–8). Due to government policy dictating the downsizing and closure of these institutions, the demand for community-based mental health services for this high-needs population will increase.

General hospitals will increasingly be expected to provide acute inpatient mental health care for individuals with a dual diagnosis living in the community. Mental health and developmental service planners have recognized hospital-based acute psychiatric care as a key component of a community’s system of mental health supports (9,10). Little is known, however, about the experience of patients with DD in acute inpatient psychiatric units.

The only Canadian investigation of hospital psychiatric service provision to individuals with a dual diagnosis published to date was done over 15 years ago.

Addington, Addington, and Ens conducted a retrospective chart review of all patients with a dual diagnosis admitted to 2 Calgary general hospitals over a 2-year period (11). They gathered information on several descriptive variables and compared the mean length of stay of this sample (24.3 days) with that of patients without DD. Results revealed similar profiles of admissions for the 2 groups and showed no significant difference in average length of stay between the groups.

To begin to understand drivers of length of stay for psychiatric care, a literature review from the general psychiatric population was conducted. The review showed that the following variables are associated with longer admissions: increased age (12–17), planned vs emergency admissions (13), discharge to a long-term care facility (18), and the presence of schizophrenia or the presence of a mood disorder (13,16,19–21). Conversely, the following factors tend to be associated with a decreased length of stay: discharge home or to another inpatient facility (18,22) and the presence of a neurotic disorder or the presence of a substance-related disorder (16,19,23). Sex is often determined to be an insignificant predictor of length of stay; only 1 study reviewed concluded that female patients stay in hospital longer (13). These variables have not been extensively studied among individuals with DD.

The current study’s purpose was to develop a profile of individuals with DD who were admitted to general hospitals for acute psychiatric care. In addition, their admissions were compared with a sample of patient admissions without DD. An analysis of factors associated with length of stay for subjects with DD was also performed. We can use this information to inform policy and program development related to service delivery to this population.