Objective The aim of this study is to investigate
the reliability and validity of the Disability Assessment
Structured Interview (DASI). The DASI is a semi-structured
interview for assessing long-term functional limitations
concerning the work disability assessment of
claimants. Methods A randomized controlled trial was
conducted. Patients applying for a work-disability pension
after 21 months of sick leave were independently interviewed
and examined either by two physicians who had
completed a DASI training period (n = 32) or by two
physicians from a control group (n = 30) without any
DASI training. Agreement percentages within both groups
of physicians, eligibility for a disability benefit, and differences
between the groups in terms of the scores given on
the work-limitation items from the Functional Ability List
(FAL) were measured to investigate reliability and concurrent
validity. To determine the content validity, the
insurance physicians who completed DASI training
(n = 8) were asked to fill out a questionnaire concerning
their opinion of the DASI. Additionally, patients filled out
a questionnaire to measure their satisfaction as to the
behavioral aspects of the physicians. Results The groups
showed no important differences in agreement percentages
(mean percentage about 80%) and eligibility for a disability
benefit. In 9 out of 21 items the physicians of the control
group indicated fewer work limitations compared to physicians
using the DASI. All physicians agreed on the fact
that the DASI was an acceptable tool in daily practice, one
that provided a realistic picture of the patient and provided
sufficient information to assess functional limitations. In
addition, between the two groups, no differences were
found as to the satisfaction of patients concerning the
behavioral aspects of the physicians. Conclusion The DASI
is a tool with a reasonable to good inter-rater reliability and
content validity, and it appears to be acceptable to both
patients and physicians. It did not improve inter-observer
agreement beyond that of usual interview procedures used
in the Netherlands. The DASI would seem to be a worthwhile
tool for collecting self-reported information in order
to assess functional limitations in claimants.