Brit.J.
Psychiat. (1976), ia8, 537-40
Cross-Validation of a Predictive Scale for Subsequent Suicidal Behaviour in an Italian Sample CHRISTA
By N. GARZO1TO, ROBERTA SIANI, ZIMMERMANN TANSELLA and M. TANSELLA
Summary. A six-point predictive scale for parasuicide repetition developed by Buglassand Horton (1974a)was testedon a group of patientsadmittedfor parasuicide to a psychiatric ward of one of the city hospitals of Verona. The scale gave a range of probability of repetition within 12 months of 15 per cent
at a score of o up to 45.5 per cent at the scores 3, 4, 5 and 6. Moreover the scale discriminated significantly between repeaters and non-repeaters. Items significantly associated with repetition in the Italian sample, which are not represented by the six-point scale were: previous parasuicide not admitted to hospital, violence received, alcohol taken at time of act, less than one year at the present address.
A substantial proportion of patients (2o—3o per cent) admitted for attempted suicide (parasuicide) are reportedtorepeatsuicidalbeha viour within a year (World Health Organiza tion,
ig68).
The
early
identification
of ‘¿repeaters'
sheet consistently discriminated repeaters from non-repeaters in three separate cohorts. The resulting
nine-item
list differs
from
the former
six-item scale by four additional items (social class V, dependence on drugs, unemployment, and a history of criminal behaviour) and the
therefore becomes important, especially when omission of one item (not living with relatives). resources are limited and special attention has to be concentrated on the group at the greatest The predictive value of these nine items is still risk of relapse (Buglass and McCullock, 5970; unknown. In the present study the validity of the six Buglass and Horton, 1974a). A new predictive scale has recently been item predictive scale has been tested in a group of patients admitted for parasuicide to the developed by Buglass and Horton (I9@a) and successfully validated for both sexes on two psychiatricward of a general hospital in successive cohorts. It consists of six items, Verona. Moreover, repeatersand non-repeaters allowing one point each, and gives a range of were compared on the basis of the six-item scale, probability of repetition within twelve months of the nine-item list and the 24-item data sheet used 5 per centat thescoreof0 up to48 per centat by Buglassand Horton (ig@a). Furthermore, thescores5 and 6.These items,selected from a singleitems significantly associatedwith repeti 24-items listdescribing the social situation, tionin our samplewere identified. clinical diagnosis and past history of the patient METHOD
are:diagnosisof sociopathy,problem in the use of alcohol,previous in-patienttreatment,pre
There were 120 patients admittedforpara
vious psychiatric out-patient treatment, previous parasuicide resulting in hospital admission, not living with relatives. In a laterpaper Buglassand Horton (1974b) examined which of the 24 items of the data 2
suicideto the PsychiatricUniversity Clinicof
Verona during the first three years of its activity (‘.4.'93'.3.'g@).
This Clinic is a 36-bed ward in a general hospital. The admissions are in general selective
‘¿37
138
CROSS-VALIDATIONOF A PREDICTIVESCALE FOR SUBSEQ@TJENT SUICIDALBEHAVIOUR
only in so far as to exclude patients under 14 years and presumably long-stay patients; corn pulsory admissions are not possible. Whereas the patients admitted may be considered as
The number of patients admitted for para suicide increased steadily over the three years, while the percentage of the identified repeaters
representative
remained
of the population
of psychiatric
RESULTs
fairly
constant
at about
26 per cent
patients in our district on the basis of the fre
(Table I). Women were slightly more likely to
quency graphic
repeat
of diagnostic data (Tansella
categories and of socio ci ci., 1974), this cannot
be said for our parasuicide patients, who are a highly selective group. Many parasuicide patients
are
admitted
to
other
psychiatric
facilities and some are discharged from the resuscitation departments of the two general hospitals of the city without having seen a psychiatrist. Moreover, the majority of the parasuicide patients admitted to our ward come from the lower social classes. Members of the middle and upper classes commonly call on private clinics or their general practitioners, and their number is therefore under-represented in our sample. In 5974 all 120 parasuicide patients (the 12 per
cent
during
the first three years) were invited
of the
letter for a follow-up
total
number
interview.
(27 per cent)
than
men
(23 per cent).
The distribution ofthesix-item scalescores by repetition is shown in Table II. The scale gives a range ofprobabilityofrepetition of 55 per cent at the score of 0 up to 45@5 per cent at the
scores 3, 4, 5 and 6, the predictive power of the scale being somewhat lower for our sample than forBritish subjects(Buglassand Horton, 1974a).The scaleislesseffective for the higher
[email protected] I FR@Petitio@of suicidal behaviour within 12 months
CohortsParas
—¿
Nters %*NInterviewed %Repea %70—71Nulcides
of admissions
by
Non-responding
patients living in the district were the social worker and interviewed The follow-up period covered one the patient's first discharge from the
visited by at home. year after clinic, and
information was collected about any subsequent parasuicidal act; the 24-item data sheet used by Buglass and Horton (1974a), including demo
graphic, clinical and social data referring to the patient at the time ofhis first discharge, was then completed. Information about 76 per cent (9' patients) ofthe total number of parasuicides
II 75—72 47 31 26Total120129!762426 72—7314596 54II 4979
*
Percentage
66 833
8
of total admissions.
[email protected] Sir-item scale (Buglass and Horton, 1974a) tested on the Italian sample Distribution
of scores by repetition, with percentages in
brackets
Score0 collected, the remainder having left the district or being untraceable. I 234 A x2 analysis ofthethreeannual cohortsfor 56TotalRepeaters4
was
repeatersand non-repeatersseparatelyshowed
thehomogeneityofthesamplesinrespect tothe 24 items collected. Only the item ‘¿previous out patient psychiatric treatment' increased signi
ficantly in frequency over the three years for the non-repeaters. All the patients were there fore treated as a single cohort, including both sexes. No patient
in this cohort
appears
ignored.
8 7 -@24Non(is)(23)(s7)4
I ‘¿0
—¿@ (j@.@)0
27 52 repeaters22 (85)(@fl) (63)33
-@67Total
twice.
Thirteen patientshad second admissionsin successive years;thesesecond admissionswere
26
1327
=ioo%26
35 5973
0 —¿@
(@)0 I09!
BY N. GARZOTIO,
ROBERTA
SIANI,
CHRISTA
ZIMMERMANN
TANSELLA
AND M. TANSELLA
139
TArnI III Rating scores (medians and ranges) and comparison of repeatersand non-repeatersusing three different item lists
(Mann-Whitney U test; two-tailed) 67)ZPMedianRangeMedianRange6items@@5()0—5o@860—4—2@I33•OI9itCITIS (N = = 24)Non-repeaters ItemlistsRepeaters(N
24iteiflS..
....
..2@2O
2—12I@70 4@100—5
4@50o-6
risk groups scoring 3 and more. This is due to the small size of the higher risk groups which are inevitably subject to fluctuation. Table III shows the comparison of repeaters and non-repeaters on the basis of the six-item scale
and
point
the nine
scale
longer
and
discriminates
item
24 item as
lists (p =
.oi)
lists. The
well
as
between
the
six two
the two
groups and is therefore preferable. Table IV shows that three items of the 24item list in our sample were associated with repetition
at
(diagnosis
of sociopathy,
the
02
level
of
significance
previous
parasuicide
not admitted to hospital, violence received) and two items at the ‘¿05 level of significance (alcohol taken at time of act, less than one year at the
present address).
—¿
[email protected]'•¿0I 0-9—2@076
DISCUSSION
The complete lack ofany official figures about parasuicidal
acts in Italy prevents
us from draw
ing any conclusions about our sample, which is likely to be a highly selective group. Despite these limitations, together with the small sample size, and despite the different cultural context in which the Buglass-Horton scale was used, the results
are
encouraging
: 83 per
cent
of the
repeaters were correctly identified (scoring i or more), which is very near to the proportion of 88 per cent found by Buglass and Horton (1974a),
and
i 7 per
cent
were
missed.
The
proportion of the non-repeaters falsely classified as potential repeaters was 67 per cent compared to 56 per cent reported by Buglass and Horton ( I 974a). Becaus@non-repeaters outnumber re peaters, the risk group (scoring i or more) contains
more than twice as many non-repeaters
as repeaters. This degree of misclassification
[email protected] IV
non-repeaters
Comparisonof repeatersand non-repeaters Items significantly associated with repetition (x' test with Tates' correction)
Non Items
Repeaters 0/ /0repeaters
/0PDiagnosis
of sociopathy
..
ofview
of
high, but from a clinical
less serious
than
a misclassification
of repeaters would be. Comparing repeaters and non-repeaters on every single item of the 24 item list, only one (diagnosis
ofsociopathy)
ofthe
five items which
were significantly associated with repetition belongs to the six-item scale. This suggests that for our sample other characteristics may be more
0/
Alcohol time215‘02of taken at act
point
is rather
..
Previous parasuicide257‘05not
important
for parasuicide
described
by the six-item
further
repetition
scale.
than
This
those
needs
investigation.
tohospital admitted
.. .. ‘¿@2present Violence received .. Less than one year at2! address
294
..3315‘05
9•02
[email protected] We wish to thank Miss Dorothy Buglau, M.Phil., and Dr. Norman Kreitman (M.R.C. Unit for Epiderniological
Studies in Psychiatry, comments.
Edinburgh)
for their helpiW
140
CROSS-VALIDATION OF A PREDICTIVE SCALE FOR SUBSEQ@UENTSUICIDAL BEHAVIOUR
T@isnu@, M., BELLINI,P., TA000NI,A. & SIcI,.Lksn,0.
REFERENCES
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—¿
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&
McCuu.ocx,
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W.
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(i@7o)
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N. Garzotto, M.D., Roberta Siani, Social Worker, Christa Zimmermann Tansella,
Dipl.-Psych.,M.5c., Clinical P.@ychologut,
M. Tansella, M.D., Istituto di Clinica Psichiatrica di Verona, Università di Padova, Policlinico, 1-37100,
(Received 2! March ‘¿975)
Verona, Italy