Feasibility of a laboratory-based protocol for measuring energy expenditure and accelerometer calibration in adults with intellectual disabilities.

Adults with intellectual disabilities experience numerous health inequalities. Targeting unhealthy lifestyle behaviours, such as high levels of sedentary behaviour and overweight/obesity, is a priority area for improving the health and adults with intellectual disabilities and reducing inequalities. Energy expenditure is a fundamental component of numerous health behaviours and an essential component of various free-living behaviour measurements, e.g. accelerometry. However, little is known about energy expenditure in adults with intellectual disabilities and no population-specific accelerometer data interpretation methods have been calibrated. The limited research in this area suggests that adults with intellectual disabilities have a higher energy expenditure, which requires further exploration, and could have significant impacts of device calibration. However, due to the complex methods required for measuring energy expenditure, it is essential to first evaluate feasibility and develop an effective protocol. This study aims to test the feasibility of a laboratory-based protocol to enable the measurement of energy expenditure and accelerometer calibration in adults with intellectual disabilities.We aimed to recruit ten adults (≥ 18 years) with intellectual disabilities. The protocol involved a total of nine sedentary, stationary, and physical activities, e.g. sitting, lying down, standing, and treadmill walking. Each activity was for 5 min, with one 10 min lying down activity to measure resting energy expenditure. Breath by breath respiratory gas exchange and accelerometry (ActiGraph and ActivPAL) were measured during each activity. Feasibility was assessed descriptively using recruitment and outcome measurement completion rates, and participant/stakeholder feedback.Ten adults (N = 7 female) with intellectual disabilities participated in this study. The recruitment rate was 50% and 90% completed the protocol and all outcome measures. Therefore, the recruitment strategy and protocol are feasible.This study addresses a significant gap in our knowledge relating to exercise laboratory-based research for adults with intellectual disabilities The findings from this study provide essential data that can be used to inform the development of future protocols to measure energy expenditure and for accelerometer calibration in adults with intellectual disabilities.

Cox regression survival analysis with compositional covariates: Application to modelling mortality risk from 24-h physical activity patterns.

Survival analysis is commonly conducted in medical and public health research to assess the association of an exposure or intervention with a hard end outcome such as mortality. The Cox (proportional hazards) regression model is probably the most popular statistical tool used in this context. However, when the exposure includes compositional covariables (that is, variables representing a relative makeup such as a nutritional or physical activity behaviour composition), some basic assumptions of the Cox regression model and associated significance tests are violated. Compositional variables involve an intrinsic interplay between one another which precludes results and conclusions based on considering them in isolation as is ordinarily done. In this work, we introduce a formulation of the Cox regression model in terms of log-ratio coordinates which suitably deals with the constraints of compositional covariates, facilitates the use of common statistical inference methods, and allows for scientifically meaningful interpretations. We illustrate its practical application to a public health problem: the estimation of the mortality hazard associated with the composition of daily activity behaviour (physical activity, sitting time and sleep) using data from the U.S. National Health and Nutrition Examination Survey (NHANES).

Differences in physical activity time-use composition associated with cardiometabolic risks.

This study investigates the association between the overall physical activity composition of the day (sedentary behavior (SB), light intensity physical activity (LIPA) and moderate-to-vigorous physical activity (MVPA)) and cardiometabolic health, and examines whether improved health can be associated with replacing SB with LIPA. A cross-sectional analysis of the Health Survey for England 2008 on N = 1411 adults was undertaken using a compositional analysis approach to examine the relationship between cardiometabolic risk biomarkers and physical activity accounting for co-dependency between relative amounts of time spent in different behavior. Daily time spent in SB, LIPA and MVPA was determined from waist-mounted accelerometry data (Actigraph GT1M) and modelled against BMI, waist circumference, waist-to-hip ratio, blood pressure, total and HDL cholesterol, HbA1c, and VO2 maximum. The composition of time spent in SB, LIPA and MVPA was statistically significantly associated with BMI, waist circumference, waist-to-hips ratio, HDL cholesterol and VO2 maximum (p < 0.001), but not HbA1c, systolic and diastolic blood pressure, or total cholesterol. Increase of relative time spent in MVPA was beneficially associated with obesity markers, HDL cholesterol, and VO2 maximum, and SB with poorer outcomes. The association of changes in LIPA depended on whether it displaced MVPA or SB. Increasing the proportion of MVPA alone may have the strongest potential association with adiposity outcomes and HDL cholesterol but similar outcomes could also be associated with a lower quantity of MVPA provided a greater quantity of SB is replaced overall with LIPA (around 10.5 min of LIPA is equivalent to 1 min of MVPA).

Characteristics of a protocol to collect objective physical activity/sedentary behaviour data in a large study: Seniors USP (understanding sedentary patterns).

The Seniors USP study measured sedentary behaviour (activPAL3, 9 day wear) in older adults. The measurement protocol had three key characteristics: enabling 24-hour wear (monitor location, waterproofing); minimising data loss (reducing monitor failure, staff training, communication); and quality assurance (removal by researcher, confidence about wear). Two monitors were not returned; 91% (n=700) of returned monitors had 7 valid days of data. Sources of data loss included monitor failure (n=11), exclusion after quality assurance (n=5), early removal for skin irritation (n=8) or procedural errors (n=10). Objective measurement of physical activity and sedentary behaviour in large studies requires decisional trade-offs between data quantity (collecting representative data) and utility (derived outcomes that reflect actual behaviour).

Comparison of single- and dual-monitor approaches to differentiate sitting from lying in free-living conditions.

High levels of sedentary time have been detrimentally linked to health outcomes. Differentiating sitting from lying may help to further understand the mechanisms associated with these health impacts. This study compares the inter-method agreement between the "single-monitor" method (thigh-worn activPAL3TM ) and a more robustly validated "dual-monitor" method (trunk and thigh-worn activPAL3TM ) in their classifications of sitting and lying under free-living conditions. Thirty-five participants (20-50 years) wore two activity monitors (thigh and trunk) for 24 hours. Total time spent lying and sitting was calculated for both methods, and agreement was determined using ICC and Bland-Altman methods. As there was no gold standard, further data were collected from five participants during structured activities that were designed to challenge classification, to better understand any disagreement between the methods. ICCs were 0.81 for sitting time and 0.64 for lying time. The single-monitor method detected less lying time than the dual-monitor method, with a mean difference of -25 minutes (95% agreement limits: -172 to 221 minutes), including three cases with extreme disagreement (mostly in daytime lying classification). The additional data collection suggested a major source of disagreement was failure of the single-monitor method to identify lying that involved no rotation around the longitudinal axis. In conclusion, there was some agreement between the single- and dual-monitor estimates of lying time under free-living conditions, but measures were not interchangeable. The main disagreement was in how the methods classified daytime lying and lying tasks involving no lateral movement. Both methods yield promise for measuring time in bed.

Systematic comparative validation of self-report measures of sedentary time against an objective measure of postural sitting (activPAL).

BACKGROUND: Sedentary behaviour is a public health concern that requires surveillance and epidemiological research. For such large scale studies, self-report tools are a pragmatic measurement solution. A large number of self-report tools are currently in use, but few have been validated against an objective measure of sedentary time and there is no comparative information between tools to guide choice or to enable comparison between studies. The aim of this study was to provide a systematic comparison, generalisable to all tools, of the validity of self-report measures of sedentary time against a gold standard sedentary time objective monitor. METHODS: Cross sectional data from three cohorts (N = 700) were used in this validation study. Eighteen self-report measures of sedentary time, based on the TAxonomy of Self-report SB Tools (TASST) framework, were compared against an objective measure of postural sitting (activPAL) to provide information, generalizable to all existing tools, on agreement and precision using Bland-Altman statistics, on criterion validity using Pearson correlation, and on data loss. RESULTS: All self-report measures showed poor accuracy compared with the objective measure of sedentary time, with very wide limits of agreement and poor precision (random error > 2.5 h). Most tools under-reported total sedentary time and demonstrated low correlations with objective data. The type of assessment used by the tool, whether direct, proxy, or a composite measure, influenced the measurement characteristics. Proxy measures (TV time) and single item direct measures using a visual analogue scale to assess the proportion of the day spent sitting, showed the best combination of precision and data loss. The recall period (e.g. previous week) had little influence on measurement characteristics. CONCLUSION: Self-report measures of sedentary time result in large bias, poor precision and low correlation with an objective measure of sedentary time. Choice of tool depends on the research context, design and question. Choice can be guided by this systematic comparative validation and, in the case of population surveillance, it recommends to use a visual analog scale and a 7 day recall period. Comparison between studies and improving population estimates of average sedentary time, is possible with the comparative correction factors provided.

The Effect of Structured Patient Education on Physical Activity in Patients with Peripheral Arterial Disease and Intermittent Claudication: A Systematic Review.

OBJECTIVES: The aim was review the components and effects of patient education interventions to improve physical activity (PA) in patients with peripheral arterial disease (PAD) and intermittent claudication (IC), and patients' experiences of these interventions. DATA SOURCES: CINAHL, Cochrane Library, Ovid, ProQuest, AMED, MEDLINE, PsycINFO, Web of Science Core Collection, and PEDRO, and Trial registers and directory of Open Access repository websites and Web of science conference proceedings were searched. Hand searching of reference lists of identified studies was also performed to identify studies that reported the effect of patient education interventions on daily PA and/or walking capacity in individuals with PAD and IC, or studies investigating patients' experiences of such interventions. METHODS: A systematic search was conducted in June 2016 (updated in March 2017). Primary outcomes were daily step count and self reported PA; the secondary outcome was absolute claudication distance. There was substantial heterogeneity in terms of modalities of patient education in the included studies; hence a narrative synthesis was implemented. RESULTS: Six studies (1087 participants) were included in the review. Findings from a small number of high quality trials demonstrated potential for PA improvement with structured education interventions. Nevertheless, evidence is currently inconclusive regarding the effect on daily PA and walking capacity of patients with IC. Patients reported that they valued the interventions studied, finding them acceptable and important in improving their PA, motivating and empowering them to self manage their condition. CONCLUSIONS: The evidence from the review is limited and inconclusive regarding the effectiveness of structured education for increasing PA in patients with PAD and IC. More rigorous trials are needed before recommendations can be made. Future interventions should consider the key criteria for a structured patient education programme, and also report patients' experiences and perceptions.

TAxonomy of Self-reported Sedentary behaviour Tools (TASST) framework for development, comparison and evaluation of self-report tools: content analysis and systematic review.

OBJECTIVE: Sedentary behaviour (SB) has distinct deleterious health outcomes, yet there is no consensus on best practice for measurement. This study aimed to identify the optimal self-report tool for population surveillance of SB, using a systematic framework. DESIGN: A framework, TAxonomy of Self-reported Sedentary behaviour Tools (TASST), consisting of four domains (type of assessment, recall period, temporal unit and assessment period), was developed based on a systematic inventory of existing tools. The inventory was achieved through a systematic review of studies reporting SB and tracing back to the original description. A systematic review of the accuracy and sensitivity to change of these tools was then mapped against TASST domains. DATA SOURCES: Systematic searches were conducted via EBSCO, reference lists and expert opinion. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: The inventory included tools measuring SB in adults that could be self-completed at one sitting, and excluded tools measuring SB in specific populations or contexts. The systematic review included studies reporting on the accuracy against an objective measure of SB and/or sensitivity to change of a tool in the inventory. RESULTS: The systematic review initially identified 32 distinct tools (141 questions), which were used to develop the TASST framework. Twenty-two studies evaluated accuracy and/or sensitivity to change representing only eight taxa. Assessing SB as a sum of behaviours and using a previous day recall were the most promising features of existing tools. Accuracy was poor for all existing tools, with underestimation and overestimation of SB. There was a lack of evidence about sensitivity to change. CONCLUSIONS: Despite the limited evidence, mapping existing SB tools onto the TASST framework has enabled informed recommendations to be made about the most promising features for a surveillance tool, identified aspects on which future research and development of SB surveillance tools should focus. TRIAL REGISTRATION NUMBER: International prospective register of systematic reviews (PROPSPERO)/CRD42014009851.

Comparison of self-reported measure of sitting time (IPAQ) with objective measurement (activPAL).

This study compared sitting time measured by a questionnaire (International Physical Activity Questionnaire; IPAQ) with concurrently measured objective sitting time from an accelerometer-based measure of thigh inclination (activPAL).Adults (n = 69), wore an activPAL for a week, and then completed the long-form 7 d recall IPAQ questionnaire. IPAQ reported sitting time (including and excluding transportation sitting) for the week, weekdays and weekend days were compared to activPAL (criterion measure) sitting time using intraclass correlation coefficients and Bland Altman plots.Confidence intervals between the IPAQ and the activPAL were wide, while correlations between the two measures were low and non-significant (0.112-0.275). Compared to a direct measure of postural sitting (activPAL), the IPAQ underestimated sitting time across the group for the whole week, both when including (mean 2.2 h d(-1)) and excluding (mean 3.4 h d(-1)) transportation sitting. Sitting was less accurately reported on weekend days than weekdays, and at lower levels of sitting on weekdays.Agreement between the IPAQ and the activPAL, a direct measure of sitting, in this study was poor. The direction of group agreement was different to comparisons using a measure of low accelerometer counts (Actigraph) as the criterion measure in previous research. Future studies should use a direct measure of sitting as a criterion measure to validate subjective measurement tools.

Development and validation of a physical activity monitor for use on a wheelchair.

STUDY DESIGN: Keeping physically active is important for people who mobilize using a wheelchair. However, current tools to measure physical activity in the wheelchair are either not validated or limited in their application. The purpose of this study was to develop and validate a monitoring system to measure wheelchair movement. METHODS: The system developed consisted of a tri-axial accelerometer placed on the wheel of a wheelchair and an analysis algorithm to interpret the acceleration signals. The two accelerometer outputs in the plane of the wheel were used to calculate the angle of the wheel. From this, outcome measures of wheel revolutions, absolute angle and duration of movement were derived and the direction of movement (forwards or backwards) could be distinguished. Concurrent validity was assessed in comparison with video analysis in 14 people with spinal cord injury using their wheelchair on an indoor track and outdoor wheelchair skills course. Validity was assessed using intraclass correlation coefficients (ICC(2,1)) and Bland-Altman plots. RESULTS: The monitoring system demonstrated excellent validity for wheel revolutions, absolute angle and duration of movement (ICC(2,1)>0.999, 0.999, 0.981, respectively) in both manual and powered wheelchairs, when the wheelchair was propelled forwards and backwards, and for movements of various durations. CONCLUSION: This study has found this monitoring system to be an accurate and objective tool for measuring detailed information on wheelchair movement and maneuvering regardless of the propulsion technique, direction and speed.

Objective assessment of mobility of the spinal cord injured in a free-living environment.

STUDY DESIGN: An exploratory study of the practicality and feasibility of an instrument. OBJECTIVES: To adapt an activity monitor for use on a wheelchair to assess long-term mobility in a free-living environment in the spinal cord injury (SCI) population, and to explore the utility of the data collected. SETTING: Glasgow, UK. METHODS: An activity monitor was adapted for use on a wheelchair wheel. The monitor was used to assess, for 1 week, the wheelchair mobility of seven participants with SCI who only used a wheelchair. In conjunction with a second monitor on the thigh the mobility of seven participants with SCI who used a wheelchair and upright mobility, and five healthy non-wheelchair users, were assessed for 1 day. RESULTS: The adapted monitor collected 1260 h of data and was suitable for use on both manual and electric wheelchairs. During 1 week, participants with SCI who only used a wheelchair spent between 4 and 13 h moving in the wheelchair, covering a distance of between 7 and 28 km. Distinct differences in mobility were shown between participants with an SCI and non-wheelchair users. The differences in time spent in mobility activities between the groups of participants with SCI were smaller. CONCLUSIONS: The system was successfully used in this group of participants with SCI, and could provide useful information on the mobility of people with SCI in a free-living environment.

Continuous monitoring of upper-limb activity in a free-living environment: a validation study.

Monitoring upper-limb activity in a free-living environment is important for the evaluation of rehabilitation. This study is a validation of the Strathclyde Upper-Limb Activity Monitor (SULAM) which records the vertical movement and position of each wrist, and assesses bimanual movement. Agreement between the SULAM and two independent video observers was assessed using interclass correlation coefficients (ICC) and the Bland and Altman method. Concurrent validity was very good for movement of each upper-limb (ICC > 0.9), and good for the vertical position of the wrist (ICC > 0.8 for wrist positions below the shoulder, ICC > 0.6 otherwise). The ICC was good (>0.8) for bimanual movement, however the SULAM systematically underreported this by approximately 15%. The SULAM could be a useful tool to assess upper-limb activity of clinical populations in their usual environment.

The functional use of the reciprocal hip mechanism during gait for paraplegic patients walking in the Louisiana State University reciprocating gait orthosis.

Reciprocally linked orthoses used for paraplegic walking have some form of linkage between the two hip joints. It has been assumed that flexion of the swinging leg is driven by extension of the stance leg. The aims of this study were to investigate the moments generated around the hip joint by the two cables in a Louisiana State University Reciprocating Gait Orthosis (LSU-RGO). Six (6) subjects were recruited from the Regional Spinal Injuries Centre at Southport, who were experienced RGO users. The cables were fitted with strain gauged transducers to measure cable tension. Foot switches were used to divide the gait into swing and stance phases. A minimum of 20 steps were analysed for each subject. Moments about the hip joint for each phase of gait were calculated. There were no moments generated by the front cable in 4 of the subjects. In only 2 subjects did the cable generate a moment that could assist hip flexion during the swing phase. These moments were very low and at best could only have made a small contribution to limb flexion. The back cable generated moments that clearly prevented bilateral flexion. It was concluded that the front cable, as used by these experienced RGO users, did not aid flexion of the swinging limb.