Objective: The study examined whether length of hospital stay is relat
ed to recidivism among psychiatric patients. A quasi-experimental appr
oach was used to address limitations of controlled and epidemiological
research. Methods: Three matched groups, each consisting of 55 inpati
ents with schizophrenia, were selected fi om public psychiatric units
with different mean lengths of stay Regression models were used to com
pare the groups on three variables: time to first readmission (surviva
l analysis), number of readmissions (ordinal legit regression), and to
tal time in the community in the postdischarge year (multiple linear r
egression). Results: An analysis based on the units with different len
gths of stay, which was similar to that typically used in controlled s
tudies, found no differences in the three outcome measures. However, a
second analysis that examined data for all patients irrespective of t
heir unit assignment found that inpatients treated for 30 days or less
relapsed sooner than those with stays longer than 30 days. The dispar
ity in results was largely due to overlapping quasi-experimental condi
tions: many patients on the short-stay units had a long lengths of sta
y; and vice versa, The first analysis supports an administrative polic
y of short stays. The second reinforces previous findings that a group
of patients, primarily young males with onset of illness at an early
age and multiple previous hospitalizations, is at greater risk of rela
pse with short-term treatment, Conclusions: The apparent contradiction
between a unit- or patient-based analysis suggests that unit-based re
sults: should be interpreted with caution when used to make clinical o
r utilization review decisions