Hannah Jenkins - Thesis submitted in partial fulfilment of the degree of Doctor of Clinical Psychology (DClinPsych)

Critical Review of the Literature:
Background: Positive Behavioural Support (PBS) based interventions for challenging behaviour should be routinely monitored and evaluated through the use of outcome measures. For PBS based interventions to develop and evolve, outcome measures must expand from only measuring behaviour change to measuring the broader issue of quality of life. It is essential that these measures are psychometrically robust.
Method: A systematic search was performed across four electronic databases to identify measures of challenging behaviour and quality of life. Measures were included if they were developed for adults with intellectual disabilities and reported psychometric properties in the original paper or subsequent validation studies. Measures were critically evaluated on their psychometric properties (specifically their reliability, validity, responsiveness and on their acceptability, feasibility, and precision). The Characteristics of Assessment Instructions for Psychiatric Disorders in Persons with Intellectual Developmental Disorders (CAPs-IDD) and established psychometric criteria guided the quality appraisal.
Results: Twenty-one measures were identified, all with varying levels of psychometric robustness. The Health of the Nation Outcome Scales for People with Learning Disabilities, Caregiver's Concerns-Quality of Life Scale, Behaviour Problem Inventory-Short, and the Choice Questionnaire were rated as having the strongest psychometric properties.
Conclusions: A combination of measures is recommended for services to use at an individual and service level for evaluating PBS based interventions. Further research is required to replicate these findings and develop new psychometrically robust instruments.
Service Improvement Project:
This project aimed to explore clinicians’ views on current memory assessment processes and to evaluate the feasibility of a new assessment process, combining high quality assessment (including an MRI scan) with research opportunities, delivered by the Brain Health Centre (BHC). A two-part (pre- and mid- pilot) qualitative design was implemented and nine clinicians took part in semi-structured interviews. Thematic analysis was used to analyse the data. Findings from pre-pilot analysis suggested that memory clinics needed to be updated and clinicians were hopeful the BHC would help improve diagnosis of dementia. Other themes developed focused on the importance of improving patient care and post-diagnostic support. Themes from mid-pilot data included the impact of Covid-19 on service delivery, and the initial outcomes of the BHC pilot, including a process of refinement and learning. Clinicians reported on the strengths of the pilot and areas for improvement when considering expanding the roll-out of this new service.
Main Research Project
Background: People with Intellectual Disabilities (ID) often face barriers accessing psychological interventions – particularly in mainstream services. This can be due to a lack of reasonable adjustments, including the absence of adapted versions of routine outcome measures. Adapted versions of the Patient Health Questionnaire-9 (PHQ-9) and the Generalised Anxiety Disorder -7 (GAD-7) have been created for adults with ID and this study investigated their psychometric properties.
Method: The adapted PHQ-9 and GAD-7 and the Glasgow Depression and Anxiety Scales (GDS-ID, GAS-ID) were administered to 47 adults with ID. Twenty-one participants formed the clinical group and 26 formed the community group to test for discriminant validity. Concurrent validity was tested by correlating the adapted PHQ-9 and GAD-7 with the GDS-ID and GAS-ID. Reliability was investigated by internal consistency and test-retest analysis.
Results: The adapted PHQ-9 and GAD-7 were able to discriminate between the clinical and community sample in terms of the total score on the depression and anxiety measures. Participants in the clinical sample scored significantly higher on the adapted PHQ-9 (t (45) = - 2.28, p = .03, 95% CI [-7.09, -.45]) and GAD-7 (t (45) = -3.52, p = .001, 95% CI [-7.44, -2.02]) than participants in the community sample. The adapted PHQ-9 correlated with the GDS-ID(r (47) = .86, p < .001) and the adapted GAD-7 correlated with the GAS-ID (r (46) = .77, p< .001). The adapted PHQ-9 (Cronbach’s a=.84, ICC=.91) and the adapted GAD-7 (Cronbach’s a=.86, ICC=.77) had good internal consistency and good test-retest reliability. Conclusions: The adapted PHQ-9 and GAD-7 appear valid and reliable measures to use in routine clinical practice.

Keywords: acceptability
systematic review
challenging behaviour
quality of life
psychometric properties
intellectual disability
feasibility
PHQ-9
reliability
service improvement
dementia
validity
outcome measures
memory assessment
GAD-7
thematic analysis
Advisor: Cooper, M
Theodore, K