IPDE - Extranet Systems - World Health Organization

128 Manual
section, if there are questions in that section that pertain to the disorders
that are being assessed.
The second option is to use the self-administered 'IPDE Screening
Questionnaire' to eliminate subjects who are unlikely to have a personality
disorder or the particular disorders of interest. The screen is
expected to produce a considerable number of false-positive but relatively
few false-negative cases vis-a-vis the interview. The rates of
case misidentification, however, are likely to vary considerably depending
on the baserates of the disorders in the population in which it is
employed.
It is especially important to recognize that personality disorder questionnaires
and semistructured clinical interviews are not interchangeable.8
Therefore, under no circumstances should the 'IPDE Screening
Questionnaire' be used to make a psychiatric diagnosis. Nor should it be
used to calculate dimensional scores, with the expectation that they will
be equivalent to those based on the IPDE itself.
Reliability and validity of the IPDE
The interrater agreement and temporal stability of the IPDE were studied
at 14 clinical facilities in 11 countries in North America, Europe, Africa,
and Asia. The field trial employed 58 psychiatrists and clinical psychologists
as interviewers and observers of 716 patients. The reliability and
stability of the IPDE were roughly similar to what has been reported with
instruments used to diagnose the psychoses, mood, anxiety, and substance
use disorders?
Establishing the validity of semistructured clinical interviews has
proved to be a more elusive undertaking, because of the absence of an
acceptable gold standard. The use of clinical consensus as that standard
is problematic without information about the reliability and validity of
the clinicians themselves. The advantage of semistructured interviews
like the IPDE, is that they have a certain procedural validity that makes
their conclusions more readily exportable, and less susceptible to institutional
and regional biases. In theory, they provide clinicians and investigators
with a more uniform method of case identification, and thus
facilitate the comparison and replication of research findings. It was the
opinion of most of the clinicians who participated in the field trial, that
the IPDE was a useful and essentially valid method of assessing personality
disorders for research purposes.