Calibration and cross-validation of the ActiGraph wGT3X+ accelerometer for the estimation of physical activity intensity in children with intellectual disabilities

Background: Valid objective measurement is integral to increasing our understanding of physical activity and sedentary behaviours. However, no population-specific cut points have been calibrated for children with intellectual disabilities. Therefore, this study aimed to calibrate and cross-validate the first population-specific accelerometer intensity cut points for children with intellectual disabilities. Methods: Fifty children with intellectual disabilities were randomly assigned to the calibration (n = 36; boys = 28, 9.53±1.08yrs) or cross-validation (n = 14; boys = 9, 9.57±1.16yrs) group. Participants completed a semi-structured school-based activity session, which included various activities ranging from sedentary to vigorous intensity. Direct observation (SOFIT tool) was used to calibrate the ActiGraph wGT3X+, which participants wore on the right hip. Receiver Operating Characteristic curve analyses determined the optimal cut points for sedentary, moderate, and vigorous intensity activity for the vertical axis and vector magnitude. Classification agreement was investigated using sensitivity, specificity, total agreement, and Cohen’s kappa scores against the criterion measure of SOFIT. Results: The optimal (AUC = .87−.94) vertical axis cut points (cpm) were ≤507 (sedentary), 1008−2300 (moderate), and ≥2301 (vigorous), which demonstrated high sensitivity (81−88%) and specificity (81−85%). The optimal (AUC = .86−.92) vector magnitude cut points (cpm) of ≤1863 (sedentary), 2610−4214 (moderate), and ≥4215 (vigorous) demonstrated comparable, albeit marginally lower, accuracy than the vertical axis cut points (sensitivity = 80−86%; specificity = 77−82%). Classification agreement ranged from moderate to almost perfect (κ = .51−.85) with high sensitivity and specificity, and confirmed the trend that accuracy increased with intensity, and vertical axis cut points provide higher classification agreement than vector magnitude cut points. Conclusions: This study provides the first valid methods of interpreting accelerometer output in children with intellectual disabilities. The calibrated physical activity cut points are notably higher than existing cut points, thus raising questions on the validity of previous low physical activity estimates in children with intellectual disabilities that were based on typically developing cut point

The effectiveness of a weight maintenance intervention for adults with intellectual disabilities and obesity: a single stranded study

Background: The evidence base for weight management programmes incorporating a weight loss and a weight maintenance phase for adults with intellectual disabilities (ID) is limited. This study describes the weight maintenance phase of a multicomponent weight management programme for adults with intellectual disability and obesity (TAKE 5). Materials and Methods: Thirty-one participants who had completed the 16 week TAKE five weight loss intervention (Phase I) were invited to participate in a 12 month weight maintenance intervention (Phase II). Content included recommendations of the National Weight Control Registry. Results: Twenty-eight participants completed Phase II with 50.4% maintaining their weight (mean weight change −0.5 kg, SD 2.2), 28.7% gaining weight (mean weight gain 5.4 kg, SD 2.2) and 21.6% losing weight (mean weight loss −8.0 kg, SD 3.0) at 12 months. Conclusion: Further research is justified to investigate the efficacy of weight loss maintenance interventions in adults with intellectual disability and obesity, using controlled study designs

Examining dimensional models of psychopathology experienced by adults with intellectual disabilities

Background: Classification systems for use in the diagnosis of mental disorders have been developed based on a categorical model of psychopathology. Although current categorical diagnostic classification systems have been found to have good utility and reliability, studies have questioned whether these systems have adequate validity. Dimensional models of psychopathology have been examined as an alternative to categorical diagnostic classification systems and found to be more strongly related to clinical parameters, such as the severity and outcome of mental disorders. A literature review found a small evidence base on dimensional models of psychopathology experienced by adults with intellectual disabilities. However, the findings were limited by small sample sizes, biased samples and inclusion of only a limited range of items of psychopathology. Furthermore, the methods of exploratory factor analysis used do not meet established best practice guidelines. Informed by the existing literature, this thesis aimed to; 1. identify a dimensional model of psychopathology experienced by adults with intellectual disabilities 2. examine the associations of a dimensional model of psychopathology with measures of the severity and outcome of mental disorders 3. compare the predictive validity of dimensional and categorical models of psychopathology. Methods: The Psychiatric Present State- Learning Disabilities (PPS-LD) was used as a structured instrument to collect psychopathology data. Exploratory factor analysis (EFA) following best practice guidelines was used to identify dimensions of psychopathology. Continuous measures representing the dimensions of psychopathology were calculated. Meeting criteria for the diagnosis of a mental disorder from the Diagnostic Criteria for Psychiatric Disorders for use with Adults with Learning Disabilities (DC-LD) was used as the variable representing the categorical model of psychopathology. Baseline data was collected on four measures of severity; the Health of the Nation Outcome Scales- Learning Disabilities (HoNOS-LD), Global Assessment of Functioning (GAF), Clinical Global Impression (CGI), and the Camberwell Assessment of Needs for Adults with Developmental and Intellectual Disabilities- Research version (CANDID-R) unmet needs. These measures were completed again at follow up 4-5 years later and change over time used as a measure of longitudinal outcome. Bivariate statistics and multivariate linear regression were used to examine the associations of the dimensions of psychopathology, and DC-LD diagnosis, with the measures of the severity of and longitudinal outcome of mental disorders. Relevant socio-clinical variables, associated with psychopathology in previous populationbased intellectual disabilities studies were included in the analyses: gender, age, living circumstances, level of intellectual disabilities, autism, Down syndrome, epilepsy, sensory impairments, mobility problems and incontinence. Key results: A model of psychopathology with four dimensions was extracted from the EFA. This model was stable in two additional EFA using random samples. There were no significant correlations between the four dimensions which were labeled depressive,organic, behaviour-affective and anxiety. Only the anxiety dimension of psychopathology was not associated with any of the measures of severity of mental disorders. The depression dimension was independently associated with severity on the HoNOS-LD (β=.413, p<.001), GAF (β=-.402, p<.001) and the CGI (β=.457, p<.001). The organic dimension was independently associated with severity on the HoNOS-LD (β=.205, p=.004), GAF(β=-.326 p<.001) and CGI (β=.266, p<.001). The behaviour-affective dimension was independently associated with severity on the HoNOS-LD (β=.332, p<.001), GAF (β=-.286, p<.001), CGI (β=.253, p<.001) and CANDID-R unmet needs (β=.178, p=.018). Level of intellectual disabilities was independently associated with severity on the HoNOS-LD and CANDID-R unmet needs. Finally, younger age (β=-.208, p=.010), living independently (β=-.599, p<.001) and not having a visual impairment (β=-.191, p=.009) were associated with greater CANDID-R unmet needs. None of the baseline measures of psychopathology were associated with longitudinal outcome on the CANDID-R unmet needs. Baseline scores on the depressive dimension were significantly associated with longitudinal outcome on the HoNOS-LD(β=.297, p=.034), GAF (β=.342, p=.002) and CGI (β=.373, p=.001). Similarly, the behaviour-affective dimension was significantly associated with longitudinal outcome on the HoNOS-LD (β=.292, p=.033), GAF (β=.244, p=.036) and CGI(β=.298, p=.009). The organic dimension was only associated with longitudinal outcome on the HoNOS-LD (β=-.382, p=.006). Individuals with mild intellectual disabilities had poorer outcomes on all four measures of longitudinal outcome.Hearing impairment was associated with poorer outcome on the GAF (β=-.483, p=.000) and CGI (β=-.331, p=.004), and poorly controlled seizures with poorer outcome on the CGI (β=-1.638, p=.004).The variable representing the categorical model of psychopathology was only independently associated with severity on the HoNOS-LD (β=.178, p=.026), and longitudinal outcome on the GAF (β=.259, p=.045) and CGI (β=.257, p=.044). However, when categorical and dimensional models were both included in the regression analyses only the dimensional model of psychopathology was retained as independently associated with these measures of severity and outcome. Conclusions: The description of a stable dimensional model demonstrates the value of using multivariate statistical methods to examine psychopathology experienced by adults with intellectual disabilities. Since the findings suggest that dimensional models have better validity than categorical models of psychopathology, the use of EFA, and other multivariate methods, could contribute to the development of valid diagnostic classification systems. The presence of affective items of psychopathology across the depressive, behaviour-affective and anxiety dimensions highlights the possible relevance of a global affective model of psychopathology. Findings reported in this thesis support the potential relevance of models of affect regulation and affective arousal to developing an understanding of psychopathology experienced by persons with intellectual disabilities. There are similarities between the dimensional model in this thesis and the tripartite model of depression and anxiety psychopathology, described in the literature- which has depressive, anxiety and general distress dimensions. Overlaps between the behaviour-affective dimension, and general distress dimension within the tripartite model, suggest that there may be an association between affective psychopathology and problem behaviours. However, it could be that this association is with affective psychopathology in the general distress dimension, rather than with depressive psychopathology, as examined in previous studies. Confirmatory factor analyses should be considered to examine the four dimension model of psychopathology. Future studies involving individuals with intellectual disabilities should examine the relevance of global affective models of psychopathology

Colonial imperative and the transformation of the Taranaki landscape : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Geography at Massey University

This study is an historical cultural geography of colonial Taranaki. I argue the history of colonial Taranaki can be better understood by focusing on the notions that underpinned the actions of the settler Government towards Maori, and the Taranaki landscape. The notions of 'civilisation', 'progress', 'savages', and 'order', are some of the concepts that were complicit in shaping the settlers' understanding of their 'reality'. These notions structured the settlers' own identity as 'civilised', and that of Maori as 'savages', and constituted the Taranaki landscape as 'wasted' and unproductive in the hands of Maori. In this context, both the landscape and Maori were constructed as needing 'culturing', to transform them from a state of 'savagery', to a state of 'civilisation'. I argue that these notions constituted a context in which the dispossession of Maori land was constructed as 'just' and natural'. Maori land was alienated through war, confiscations, the compensation process, and the 'rule of law'. A legislative framework was set up to include Maori within its authority, based on the notions above. Maori resistance to the assertion of that authority was greeted as further proof of the 'savageness' of Maori. The settler Government maintained a paternalistic attitude towards Maori, and indirectly caused war and injustice through their refusal to deal with Maori as equals. The identity of the settlers, and of Pakeha today, is based on a conventional history that represents the colonisation of New Zealand as a benevolent and beneficial process for Maori and Pakeha. I argue that by challenging this history and asserting the existence of other historical experiences, unseen by the conventional history, the politics of 'being Pakeha' and 'being Maori' can be engaged in. This engagement is crucial to the ability of New Zealand society to move beyond colonialism, to a state of post-coloniality

Tiv-Model : an empirically validated design methodology for complex space systems

In response to emergent space systems engineering industry challenges, this thesis explored work on the following; 1. The development of engineering design methodologies, following a design process and proposing a baseline of requirements for new methodologies called the “Methodology Requirements Document”. 2. A new design engineering methodology called the “Tiv-Model”, which combines novel academic research into a space systems engineering life cycle model that addresses the emergent challenges. 3. A procedure for verifying and validating design models, based on an existing technique called the “Validation Square”, incorporated to boost the waning confidence industry drivers have of academic models. Through literature research, the Methodology Requirements Document is formed, and the TivModel is created with the aim of optimising the development of space systems. Its novel aspects include a model-based verification technique (called multi-perspective modelling), a focus on teachability for novice engineers and incorporation of other new academic findings, to utilise useful research. The verification and validation of the Tiv-Model is used as an example to create a procedure for academics to validate their own models. A combination of comparative benchmark studies and a focus group was used to continuously improve the model and drive it through the design process. The Tiv-Model rated better in student projects than its benchmark (V-Model) in 13 out of 24 survey categories in a t-test study, and underwent changes requested by industry veterans to finalise the model.In response to emergent space systems engineering industry challenges, this thesis explored work on the following; 1. The development of engineering design methodologies, following a design process and proposing a baseline of requirements for new methodologies called the “Methodology Requirements Document”. 2. A new design engineering methodology called the “Tiv-Model”, which combines novel academic research into a space systems engineering life cycle model that addresses the emergent challenges. 3. A procedure for verifying and validating design models, based on an existing technique called the “Validation Square”, incorporated to boost the waning confidence industry drivers have of academic models. Through literature research, the Methodology Requirements Document is formed, and the TivModel is created with the aim of optimising the development of space systems. Its novel aspects include a model-based verification technique (called multi-perspective modelling), a focus on teachability for novice engineers and incorporation of other new academic findings, to utilise useful research. The verification and validation of the Tiv-Model is used as an example to create a procedure for academics to validate their own models. A combination of comparative benchmark studies and a focus group was used to continuously improve the model and drive it through the design process. The Tiv-Model rated better in student projects than its benchmark (V-Model) in 13 out of 24 survey categories in a t-test study, and underwent changes requested by industry veterans to finalise the model

Use of behaviour change techniques in lifestyle change interventions for people with intellectual disabilities: A systematic review

Background: People with intellectual disabilities (ID) experience more health problems and have different lifestyle change needs, compared with the general population. Aims: To improve lifestyle change interventions for people with ID, this review examined how behaviour change techniques (BCTs) were applied in interventions aimed at physical activity, nutrition or physical activity and nutrition, and described their quality. Methods and procedures: After a broad search and detailed selection process, 45 studies were included in the review. For coding BCTs, the CALO-RE taxonomy was used. To assess the quality of the interventions, the Physiotherapy Evidence Database (PEDro) scale was used. Extracted data included general study characteristics and intervention characteristics. Outcomes and results: All interventions used BCTs, although theory-driven BCTs were rarely used. The most frequently used BCTs were ‘provide information on consequences of behaviour in general’ and ‘plan social support/social change’. Most studies were of low quality and a theoretical framework was often missing. Conclusion and implications: This review shows that BCTs are frequently applied in lifestyle change interventions. To further improve effectiveness, these lifestyle change interventions could benefit from using a theoretical framework, a detailed intervention description and an appropriate and reliable intervention design which is tailored to people with ID

Parental perceptions of facilitators and barriers to physical activity for children with intellectual disabilities: A mixed methods systematic review

Background: There is a need increase our understanding of what factors affect physical activity participation in children with intellectual disabilities (ID) and develop effective methods to overcome barriers and increase activity levels. Aim: This study aimed to systematically review parental perceptions of facilitators and barriers to physical activity for children with ID. Methods: A systematic search of Embase, Medline, ERIC, Web of Science, and PsycINFO was conducted (up to and including August, 2017) to identify relevant papers. A meta-ethnography approach was used to synthesise qualitative and quantitative results through the generation of third-order themes and a theoretical model. Results: Ten studies were included, which ranged from weak to strong quality. Seventy-one second-order themes and 12 quantitative results were extracted. Five third-order themes were developed: family, child factors, inclusive programmes and facilities, social motivation, and child’s experiences of physical activity. It is theorised that these factors can be facilitators or barriers to physical activity, depending on the information and education of relevant others, e.g. parents and coaches. Conclusions: Parents have an important role in supporting activity in children with ID. Increasing the information and education given to relevant others could be an important method of turning barriers into facilitators

A meta-analysis of working memory in individuals with autism spectrum disorders

Background: Autism spectrum disorders (ASD) are lifelong neurodevelopmental disorders. It is not clear whether working memory (WM) deficits are commonly experienced by individuals with ASD. Aim: To determine whether individuals with ASD experience significant impairments in WM and whether there are specific domains of working memory that are impaired. Methods: We conducted a meta-analysis using four electronic databases EMBASE (OVID), MEDLINE (OVID), PsychINFO (EBSCOHOST), and Web of Science, to examine the literature to investigate whether people with ASD experience impairments related to WM. Meta-analyses were conducted separately for phonological and visuospatial domains of WM. Subgroup analyses investigated age and intelligence quotient as potential moderators. Results: A total of 29 papers containing 34 studies measuring phonological and visuospatial domains of WM met the inclusion criteria. WM scores were significantly lower for individuals with ASD compared to typically developed (TD) controls, in both the visuospatial domain when investigating accuracy (d: -0.73, 95% CI -1.04 to -0.42, p &lt; 0.05) and error rates (d: 0.56, 95% CI 0.25 to 0.88, p&lt;0.05), and the phonological domain when investigating accuracy (d:-0.67, 95% CI -1.10 to -0.24, p&gt;0.05) and error rate (d: 1.45, 95% CI -0.07 to 2.96, p = 0.06). Age and IQ did not explain the differences in WM in ASD. Conclusions: The findings of this meta-analysis indicate that across the lifespan, individuals with ASD demonstrate large impairments in WM across both phonological and visuospatial WM domains when compared to healthy individuals

A cluster randomised control trial of a multi-component weight management programme for adults with intellectual disabilities and obesity

There have been few published controlled studies of multi-component weight management programmes that include an energy deficit diet (EDD), for adults with intellectual disabilities and obesity. The objective of this study was to conduct a single-blind, cluster randomised controlled trial comparing a multi-component weight management programme to a health education programme. Participants were randomised to either TAKE 5, which included an EDD or Waist Winners Too (WWToo), based on health education principles. Outcomes measured at baseline, 6 months (after a weight loss phase) and 12 months (after a 6-month weight maintenance phase), by a researcher blinded to treatment allocation, included: weight; BMI; waist circumference; physical activity; sedentary behaviour and health-related quality of life. The recruitment strategy was effective with fifty participants successfully recruited. Both programmes were acceptable to adults with intellectual disabilities, evidenced by high retention rates (90 %). Exploratory efficacy analysis revealed that at 12 months there was a trend for more participants in TAKE 5 (50·0 %) to achieve a clinically important weight loss of 5-10 %, in comparison to WWToo (20·8 %) (OR 3·76; 95 % CI 0·92, 15·30; 0·064). This study found that a multi-component weight management programme that included an EDD, is feasible and an acceptable approach to weight loss when tailored to meet the needs of adults with intellectual disabilities and obesity

The effects of multi-component weight management interventions on weight loss in adults with intellectual disabilities and obesity: a systematic review and meta-analysis of randomised controlled trials

Background: Adults with intellectual disabilities have been shown to experience higher rates of obesity in comparison to the general population. Aim: To examine the effectiveness of randomised controlled trials of multi-component weight management interventions for adults with intellectual disabilities and overweight/obesity. Methods and procedures: A systematic search of six electronic databases was conducted from database inception to January 2016. Risk of bias was assessed by the Cochrane Collaboration tool. Behavioural change techniques were defined by coding against the Coventry Aberdeen LOndon REfined (CALO-RE) taxonomy. Meta-analyses were conducted as Weighted Mean Difference (WMD) between intervention and control/comparator intervention. Outcomes and results: Six randomised controlled trials were included. The interventions did not adhere to clinical recommendations [the inclusion of an energy deficit diet (EDD), physical activity, and behaviour change techniques]. Meta-analysis revealed that current multi-component weight management interventions are not more effective than no treatment (WMD: −0.38 kg; 95% CI −1.34 kg to 0.58 kg; p = 0.44). Conclusion and implications: There is a paucity of randomised controlled trials of multi-component weight management interventions for adults with intellectual disabilities and overweight/ obesity. Current interventions, based on a health education approach are ineffective. Future longterm interventions that include an EDD and adhere to clinical recommendations on the management of obesity are warranted