Wolf et al reported a clinical prediction rule for a patient committing a violent crime after discharge from a secure psychiatric hospital. This can help to identify a patient who may benefit from careful follow-up. The authors are from the University of Oxford, Karolinska Institute, Orebro University and the Oxford Health NHS Foundation Trust.
FoVOx stands for Forensic Psychiatry and Violence tool Oxford.
Patient selection: inpatient of a secure psychiatric hospital
Parameters:
(1) sex
(2) age at discharge in years
(3) history of previous violent crime
(4) primary diagnosis at discharge
(5) current drug use disorder
(6) current alcohol use disorder
(7) personality disorder
(8) employment prior to admission
(9) number of previous inpatient episodes
(10) lifetime drug use disorder
(11) length of stay in forensic hospital in months
|
Parameter
|
Finding
|
Points
|
|
sex
|
male
|
0
|
|
|
female
|
-0.8407
|
|
age at discharge
|
|
-0.0299 * (age)
|
|
previous violent crime
|
no
|
0
|
|
|
yes
|
1.1682
|
|
primary diagnosis
|
schizophrenia spectrum
|
0
|
|
|
bipolar
|
0.5994
|
|
|
unipolar depression
|
0.2867
|
|
|
anxiety disorder
|
0.1142
|
|
|
other
|
0.304
|
|
drug use disorder
|
no
|
0
|
|
|
yes
|
-0.1188
|
|
alcohol use disorder
|
no
|
0
|
|
|
yes
|
0.2288
|
|
personality disorder
|
no
|
0
|
|
|
yes
|
0.3052
|
|
employment
|
no
|
0
|
|
|
yes
|
-0.578
|
|
previous inpatient episodes
|
< 5
|
0
|
|
|
>= 5
|
-0.4676
|
|
lifetime drug use
|
no
|
0
|
|
|
yes
|
0.7964
|
|
length of stay
|
< 12 months
|
0
|
|
|
>= 12 months
|
-0.4576
|
where:
• In Appendix Table 6 the entries for sex and age appear to be flipped, as compared to the hazard ratios shown in Table 2 of the article.
score =
= SUM(points for all of the parameters)
X = EXP(score)
probability of violent offense within 12 months =
= 1 - (0.9280^X)
probability of violent offense within 24 months =
= 1 - (0.8762^X)
Performance:
• The area under the ROC curve is 0.77.
