A statistical model for length of psychiatric in-patient treatment and an analysis of contributing factors.
OBJECTIVE
Direct illness costs in psychiatry are strongly related to the length of in-patient stay (LOS). Prior studies have shown that LOS depends upon many factors; however, there is no systematic work on their interrelation and relative contribution.


METHODS
A detailed statistical analysis of the factors explaining LOS for n = 4,706 consecutive admissions (1994-97) to the psychiatric hospital of the University of Tübingen is presented.


RESULTS
The distribution of LOS follows an exponential decay function, suggesting a hazard-based process. Cox regression indicates that the incidence of discharge and hence LOS is modulated by a number of illness-related and other factors, and their relationship is explored.


CONCLUSIONS
While a linear model is commonly assumed, LOS in psychiatry is governed by a hazard-based process. As a tool in quality management, LOS data for psychiatric hospitals might be routinely analyzed and the effects of non-illness-related factors minimized.
Stevens
A
A
Department of Psychiatry, University of Tübingen, Germany.
Hammer
K
K
Buchkremer
G
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006760:Hospitalization / Q000191:economics; D006778:Hospitals, Psychiatric; D006801:Humans; D007902:Length of Stay / Q000191:economics; D008297:Male; D001523:Mental Disorders / Q000191:economics* / Q000534:rehabilitation*; D008605:Mental Health Services / Q000458:organization & administration; D008875:Middle Aged; D010351:Patient Discharge / Q000706:statistics & numerical data; D012189:Retrospective Studies