Page 42 - Post-traumatic stress disorder in adults with mild intellectual disability: Screening, assessment, and brief intensive EMDR therapy

Chapter 2
Procedure
The data were collected between November 2021 and June 2022. Trained
master students of Radboud University and Vrije Universiteit Amsterdam
and the first author conducted the DITS-ID-adults, then the BSI and finally
the IES-ID were administered to clients. Interviews were conducted in a
quiet room at the facility. All DITS-ID-adults’ interviews were recorded on
video to assess interrater reliability. Three participants did not complete
the DITS-ID-adults (see Participants and Setting). In addition, the BPI
and ADESS were sent by postal mail or e-mail to a person who knew the
participant well. Both, the BPI and ADESS were completed by the same
person for each participant: a professional caregiver for 83 participants
and by a parent or husband for 11 participants.
We randomly selected 35 recorded interviews to assess the interrater
reliability of the DITS-ID-adults. On a question-by-question basis, a second
independent rater scored all items of the event and symptom sections
of the DITS-ID-adults. The second rater assessed whether the event met
criterion A and whether the participant met the criteria for PTSD.
Statistical Analyses
SPSS version 27 was used to analyze the data. First, a descriptive analysis
was performed. To assess the interrater reliability of the DITS-ID-adults,
Cohen’s kappa was calculated for all items of the event section, symptom
section, whether the reported event met criterion A, and the presence or
absence of PTSD. To examine construct validity, correlation coefficients
were calculated between the BSI-18, BPI, IES-ID, ADESS and total number
of PTSD symptoms (DITS-ID-adults). Point-biserial correlations were
calculated between the BSI-18, BPI, IES-ID, ADESS and PTSD classification.
The association reporting a PTSD criterion A event and fulfilling the
PTSD symptom criteria was tested with chi-square and an independent
samples t-test to examine the difference between the mean number of
reported type A criterion events in participants who did and those who did
not fulfill the PTSD criteria. If more than 10% of the items of a total score
or subscale on the DITS-ID-adults, BSI-18, BPI, IES-ID or ADESS were not
scored, the scores of that scale were not included in the analyses (see
results for the number of participants per total scale and subscale). The
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