The author describes a computer-based model that derives nonnursing st
affing requirements from quantifiable performance expectations for str
uctured psychotherapy and rehabilitation therapy. Input variables incl
ude treatment mode, contact hours, patient volume (average daily censu
s and average length of stay), hours of structured therapy per week, a
ssessment and discharge activities, and ancillary staff activities. Ou
tput variables are number of staff needed weekly productivity ratios s
uch as hours of direct service per full-time-equivalent position and n
ew patients served per full-time-equivalent position, and hours of str
uctured therapy per day per patient. Initial validation of the model c
ompared its predictions of staffing requirements with predictions base
d on staffing ratios derived from the literature and with actual staff
ing levels at the author's institution. The model was used in an analy
sis of two hypothetical scenarios showing the effects of managed care
on variables that influence staffing. The results showed that as avera
ge length of stay decreases under managed care, reimbursement based on
number of patients served at one time decreases, although costs of pr
oviding treatment increase because the program needs more staff to han
dle the increased number of admissions and discharges.