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

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

Understanding and validating accelerometry as a measure of physical activity in children with intellectual disabilities

Background Physical activity in children with intellectual disabilities is a neglected area of study, which is most apparent in relation to physical activity measurement research. Although objective measures, specifically accelerometers, are widely used in research involving children with intellectual disabilities, existing research is based on measurement methods and data interpretation techniques generalised from typically developing children. However, due to physiological and biomechanical differences between these populations, questions have been raised in the existing literature on the validity of generalising data interpretation techniques from typically developing children to children with intellectual disabilities. Therefore, there is a need to conduct population-specific measurement research for children with intellectual disabilities and develop valid methods to interpret accelerometer data, which will increase our understanding of physical activity in this population. Methods Study 1: A systematic review was initially conducted to increase the knowledge base on how accelerometers were used within existing physical activity research involving children with intellectual disabilities and to identify important areas for future research. A systematic search strategy was used to identify relevant articles which used accelerometry-based monitors to quantify activity levels in ambulatory children with intellectual disabilities. Based on best practice guidelines, a novel form was developed to extract data based on 17 research components of accelerometer use. Accelerometer use in relation to best practice guidelines was calculated using percentage scores on a study-by-study and component-by-component basis. Study 2: To investigate the effect of data interpretation methods on the estimation of physical activity intensity in children with intellectual disabilities, a secondary data analysis was conducted. Nine existing sets of child-specific ActiGraph intensity cut points were applied to accelerometer data collected from 10 children with intellectual disabilities during an activity session. Four one-way repeated measures ANOVAs were used to examine differences in estimated time spent in sedentary, moderate, vigorous, and moderate to vigorous intensity activity. Post-hoc pairwise comparisons with Bonferroni adjustments were additionally used to identify where significant differences occurred. Study 3: The feasibility on a laboratory-based calibration protocol developed for typically developing children was investigated in children with intellectual disabilities. Specifically, the feasibility of activities, measurements, and recruitment was investigated. Five children with intellectual disabilities and five typically developing children participated in 14 treadmill-based and free-living activities. In addition, resting energy expenditure was measured and a treadmill-based graded exercise test was used to assess cardiorespiratory fitness. Breath-by-breath respiratory gas exchange and accelerometry were continually measured during all activities. Feasibility was assessed using observations, activity completion rates, and respiratory data. Study 4: Thirty-six children with intellectual disabilities participated in a semi-structured school-based physical activity session to calibrate accelerometry for the estimation of physical activity intensity. Participants wore a hip-mounted ActiGraph wGT3X+ accelerometer, with direct observation (SOFIT) used as the criterion measure. Receiver operating characteristic curve analyses were conducted to determine the optimal accelerometer cut points for sedentary, moderate, and vigorous intensity physical activity. Study 5: To cross-validate the calibrated cut points and compare classification accuracy with existing cut points developed in typically developing children, a sub-sample of 14 children with intellectual disabilities who participated in the school-based sessions, as described in Study 4, were included in this study. To examine the validity, classification agreement was investigated between the criterion measure of SOFIT and each set of cut points using sensitivity, specificity, total agreement, and Cohen’s kappa scores. Results Study 1: Ten full text articles were included in this review. The percentage of review criteria met ranged from 12%−47%. Various methods of accelerometer use were reported, with most use decisions not based on population-specific research. A lack of measurement research, specifically the calibration/validation of accelerometers for children with intellectual disabilities, is limiting the ability of researchers to make appropriate and valid accelerometer use decisions. Study 2: The choice of cut points had significant and clinically meaningful effects on the estimation of physical activity intensity and sedentary behaviour. For the 71-minute session, estimations for time spent in each intensity between cut points ranged from: sedentary = 9.50 (± 4.97) to 31.90 (± 6.77) minutes; moderate = 8.10 (± 4.07) to 40.40 (± 5.74) minutes; vigorous = 0.00 (± .00) to 17.40 (± 6.54) minutes; and moderate to vigorous = 8.80 (± 4.64) to 46.50 (± 6.02) minutes. Study 3: All typically developing participants and one participant with intellectual disabilities completed the protocol. No participant met the maximal criteria for the graded exercise test or attained a steady state during the resting measurements. Limitations were identified with the usability of respiratory gas exchange equipment and the validity of measurements. The school-based recruitment strategy was not effective, with a participation rate of 6%. Therefore, a laboratory-based calibration protocol was not feasible for children with intellectual disabilities. Study 4: The optimal vertical axis cut points (cpm) were ≤ 507 (sedentary), 1008−2300 (moderate), and ≥ 2301 (vigorous). Sensitivity scores ranged from 81−88%, specificity 81−85%, and AUC .87−.94. The optimal vector magnitude cut points (cpm) were ≤ 1863 (sedentary), ≥ 2610 (moderate) and ≥ 4215 (vigorous). Sensitivity scores ranged from 80−86%, specificity 77−82%, and AUC .86−.92. Therefore, the vertical axis cut points provide a higher level of accuracy in comparison to the vector magnitude cut points. Study 5: Substantial to excellent classification agreement was found for the calibrated cut points. The calibrated sedentary cut point (ĸ =.66) provided comparable classification agreement with existing cut points (ĸ =.55−.67). However, the existing moderate and vigorous cut points demonstrated low sensitivity (0.33−33.33% and 1.33−53.00%, respectively) and disproportionately high specificity (75.44−.98.12% and 94.61−100.00%, respectively), indicating that cut points developed in typically developing children are too high to accurately classify physical activity intensity in children with intellectual disabilities. Conclusions The studies reported in this thesis are the first to calibrate and validate accelerometry for the estimation of physical activity intensity in children with intellectual disabilities. In comparison with typically developing children, children with intellectual disabilities require lower cut points for the classification of moderate and vigorous intensity activity. Therefore, generalising existing cut points to children with intellectual disabilities will underestimate physical activity and introduce systematic measurement error, which could be a contributing factor to the low levels of physical activity reported for children with intellectual disabilities in previous research

Mental health, potential minority stressors and resilience: evidence from a crosssectional survey of gay, bisexual and other men who have sex with men within the Celtic nations

Background: Gay, bisexual and other men who have sex with men (GBMSM) are at a greater risk of mental health problems, such as anxiety and depression, than heterosexual adults. Numerous factors and stressors have been reported to impact men’s mental health, although it has been suggested that resilience could have a protective effect. The aim of this study is to explore mental health, minority stressors, and resilience among a large online cross-sectional survey of GBMSM in the Celtic nations. Methods: Data for this cross-sectional study were collected from the Social Media, GBMSM and Sexual and Holistic Health (SMMASH2) self-report online survey. Participants (n = 3077) were recruited via gay sociosexual media in Scotland, Wales, Northern Ireland, and the Republic of Ireland. Binary logistic regression analyses were conducted to identify factors that increased the odds of moderate-to-severe anxiety and depression. Potentially relevant variables (p < 0.05) were carried forward in hierarchal logistic regression analyses. Results: The prevalence of moderate-to-severe anxiety and depression was 19.9 and 14.4%, respectively. Having a disability (OR = 1.73) and having financial worries sometimes/all of the time (OR = 1.93) increased the odds of having moderate-to-severe depression and anxiety, respectively. No minority stressors were associated with depression, whereas experiencing any form of relationship abuse in the last 12 months significantly increased the odds of anxiety (OR = 1.50). Resilience, namely a sense of coherence, had a protective effect and significantly reduced the odds of moderate-to-severe depression (OR = 0.85) and anxiety (OR = 0.89). Conclusions: Disability and financial worries were associated with increased depression and anxiety, respectively, while resilience had a protective effect for GBMSM in the SMMASH2 study. Future research is needed to better understand the role of resilience and the challenges and stresses of everyday life and intersecting health problems. Future research is also needed that incorporates the perspectives of those most affected by mental ill-health to co-develop effective solutions that respond to their contextual surroundings

Patterns of objectively measured sedentary behaviour in adults with intellectual disabilities

The purpose of this study was to investigate the patterns of objectively measured sedentary behaviour in adults with intellectual disabilities. Baseline accelerometer data were pooled from two randomized controlled trials of lifestyle behaviour change programmes for adults with intellectual disabilities. Patterns of sedentary behaviours were computed including total volume, number, and duration of bouts and breaks. Participants spent >70% of the day sedentary (8 hr), which was generally accumulated in short sedentary bouts (<10 min). Participants were engaged in significantly more sedentary time during the morning, although differences between time of day were small (mean bout duration range: 19.8-22.3 min). The findings add valuable insight into the patterns of sedentary behaviours among adults with intellectual disabilities. Further research investigating the patterns and context of sedentary behaviour is required to develop targeted interventions to reduce total sedentary time in adults with intellectual disabilities

Correlates of objectively measured sedentary time in adults with intellectual disabilities

Sedentary behaviour is an independent risk factor for adverse health conditions. Adults with intellectual disabilities spend a high proportion of their day engaged in sedentary behaviour, however, there is limited evidence on potential correlates of objectively measured sedentary behaviour in this population group. In Glasgow, UK from July to September 2017, a secondary analysis of pooled baseline accelerometer data from two randomised controlled trials of lifestyle behaviour change programmes was conducted. Backwards linear regression was used to investigate the associations between demographic, biological, and environmental correlates and objective measure of sedentary behaviour (percentage of time spent sedentary). One-hundred and forty-three participants provided valid accelerometer data. Mean percentage time spent sedentary (adjusted for wear time) was 72.9% [Standard Deviation (SD) = 8.7] per day. In the final model, physical and mental health problems were significantly (p < 0.05) associated with increased percentage time spent sedentary. This is the first study to provide evidence on multi-level, demographic, biological, and environmental correlates of objectively measured sedentary behaviour in adults with intellectual disabilities. To inform the development of interventions to modify sedentary behaviours in adults with intellectual disabilities, further research is required including a wide range of socio-ecological correlates

Individual, interpersonal, and environmental correlates of sedentary behaviours in adults with intellectual disabilities

Background: Sedentary behaviours have adverse health outcomes and adults with intellectual disabilities are at a higher risk of unhealthy lifestyle behaviours. The lack of knowledge relating to sedentary behaviours in adults with intellectual disabilities has impeded the development of effective interventions. This study aimed to investigate individual, interpersonal and environmental correlates that are associated with sedentary behaviours in adults with intellectual disabilities. Method: A secondary analysis of data from The UK Household Longitudinal Study (Understanding Society; collected 2011–2013) was conducted. Twenty-two predictor variables were included in a stepwise logistic regression, with TV hours during weekdays (≤3 and &gt;3 h/day) used as a proxy for sedentary behaviours. A sample of 266 adults, with mean age of 37.9 and range from 18 to 49 years old, with intellectual disabilities were identified. Because 63.9% were female, 62.4% had children and 28.2% were employed, the sample is likely to be most representative of more able adults with intellectual disabilities. Results: A significant interaction term between having children and neighbourhood status was found in the initial model so separate models for good and poor-quality neighbourhoods are reported. Having children only had a significant effect to lower the odds of high TV time among participants living in good quality neighbourhoods (OR 0.10, 95% CI 0.03, 0.25). However, for people living in poor quality neighbourhoods it was better quality leisure services that was associated with lower odds of high TV time (OR 0.48, 95% CI 0.23, 0.90). Being employed only significantly reduced the odds of high TV time in the good quality neighbourhood model (OR 0.35, 95% CI 0.12, 0.78). These effects highlight the importance of environmental effects on lifestyle behaviours of adults with intellectual disabilities. Conclusions: Future research should aim to expand our understanding of environmental effects on the sedentary behaviours and other lifestyle behaviours of adults with intellectual disabilities

Feasibility of the Go2Play Active Play intervention for increasing physical and social development in children with intellectual disabilities

Introduction: An active play is designed to increase children’s physical activity levels and fundamental movement skills through outdoor play and is well-suited to the needs of children with intellectual disabilities. However, no active play interventions have included children with intellectual disabilities. This study aims to investigate the feasibility of a school-based active play intervention for children with intellectual disabilities. Method: Children aged 7–12 years who had intellectual disabilities and were independently ambulatory were eligible. This single-group 17-week intervention was implemented in two additional support needs schools. It consisted of a weekly 1-h active play session incorporating 30 min of structured games and 30 min of free play. Feasibility of recruitment/retention, adherence, and outcome measures were investigated. Outcome measures included school-based physical activity (ActiGraph GT3X+ accelerometer), fundamental movement skills (Test of Gross Motor Development-2), and social interactions (Playground Observation of Peer Engagement). Staff feedback was collected via open-ended questionnaire. Feasibility was investigated using descriptive statistics and questionnaire data analyzed using thematic analysis. Potential pre-post changes were investigated for school-based physical activity, fundamental movement skills, and social interactions using paired samples t tests. The progression criteria were (1) &gt; 50% of eligible participants recruited, (2) &gt; 50% of recruited participants retained, (3) &gt; 50% of active play sessions spent in MVPA, and (4) &gt; 50% of participants complete outcome measurements. Results: All progression criteria were met. Recruitment and retention rates were 100% (n=21 participants). Intervention adherence was high, based on data from n=1 school, with 90% of participants attending all sessions. Measuring physical activity using accelerometry and fundamental movement skills using the Test of Gross Motor Development-2 were feasible. The Playground Observation of Peer Engagement tool to measure social interactions was not feasible. The only significant increase post-intervention was for social interactions during structured play (pre–post mean difference: –1.46, 95% CI −1.99, −0.93). Staff feedback was positive with the intervention well received by schools and potential benefits post-intervention identified by teachers. Conclusion: The Go2Play Active Play intervention is feasible for children with intellectual disabilities. Future research should further investigate feasibility and implementation on a larger scale using a pilot cluster randomised controlled trial

Effects of exercise training programmes on fasting gastrointestinal appetite hormones in adults with overweight and obesity: a systematic review and meta-analysis

A systematic review and meta-analysis was performed to determine the effect of exercise training on fasting gastrointestinal appetite hormones in adults living with overweight and obesity. For eligibility, only randomised controlled trials (duration ≥ four weeks) examining the effect of exercise training interventions were considered. This review was registered in the International Prospective Register of Systematic Reviews (CRD42020218976). The searches were performed on five databases: MEDLINE, EMBASE, Cochrane Library, Web of Science, and Scopus. The initial search identified 13204 records. Nine studies, which include sixteen exercise interventions, met the criteria for inclusion. Meta-analysis was calculated as the standardised mean difference (Cohen's d). Exercise training had no effect on fasting concentrations of total ghrelin (d: 1.06, 95% CI -0.38 to 2.50, P = 0.15), acylated ghrelin (d: 0.08, 95% CI: −0.31 to 0.47, P = 0.68) and peptide YY (PYY) (d = −0.16, 95% CI: −0.62 to 0.31, P = 0.51) compared to the control group. Analysis of body mass index (BMI) (d: −0.31, 95% CI: −0.50 to −0.12, P &lt; 0.01) and body mass (d: −0.22, 95% CI: −0.42 to −0.03, P = 0.03) found a significant reduction after exercise compared to controls. Overall, exercise interventions did not modify fasting concentrations of total ghrelin, acylated ghrelin, and PYY in individuals with overweight or obesity, although they reduced body mass and BMI. Thus, any upregulation of appetite and energy intake in individuals with overweight and obesity participating in exercise programmes is unlikely to be related to fasting concentrations of gastrointestinal appetite hormones

Associations between motor competence and physical activity levels of children with intellectual disabilities and/or autism spectrum disorder: movement matters

Motor competence is important for lifelong physical activity (PA). The current study aimed to examine associations between PA and motor competence. In total, 43 children aged 7–12 years with intellectual disabilities and/or autism spectrum disorder completed anthropometric measures, the Bruininks-Oseretsky Test of Motor Proficiency-2, and wore a wrist accelerometer to capture total PA, moderate-to-vigorous PA (MVPA), average acceleration, and intensity gradient. No significant associations were found between PA outcomes and motor competence. Motor competence performance was commonly ‘below average’ or ‘average’. The weakest subtests were upper limb coordination and strength. The strongest subtest was running speed and agility. Total weekly MVPA was 336.1 ± 150.3 min, higher than UK recommendations of 120-180 per week for disabled children and young people. Larger scale studies are needed to better understand the relationship between PA and motor competence. Future research should also consider the influence of environmental factors on PA in this group