Truth be told: evidence of wheelchair users' accuracy in reporting their height and weight.
ABSTRACT: To examine whether wheelchair users' self-reports of height and weight differed significantly from direct measurements and whether weight category classifications differed substantially when based on self-reported or measured values.Single group, cross-sectional analysis. Analyses included paired t tests, chi-square test, analysis of variance, and Bland-Altman agreement analyses.A university-based exercise lab.Community-dwelling wheelchair users (N=125).Not applicable.Participants' self-reported and measured height, weight, and body mass index.Paired t tests revealed that there were significant differences between wheelchair users' self-reported and measured values for height (difference of 3.1±7.6cm [1.2±3.0in]), weight (-1.7±6.5kg [-3.6±14.2lb]), and BMI (-1.6±3.3). These discrepancies also led to substantial misclassification into weight categories, with reliance on self-reported BMI underestimating the weight status of 20% of the sample.Our findings suggest that similar to the general population, wheelchair users are prone to errors when reporting their height and weight and that these errors may exceed those noted in the general population.
Project description:PURPOSE:Self-reported weight, height, and body mass index (BMI) are commonly used in cancer epidemiology studies, but information on the validity of self-reports among cancer survivors is lacking. This study aimed to evaluate the validity of these self-reported measures among African American (AA) breast cancer survivors, known to have high obesity prevalence. METHODS:We compared the self-reported and measured values among 243 participants from the Women's Circle of Health Follow-Up Study (WCHFS), a population-based longitudinal study of AA breast cancer survivors. Multivariable-adjusted linear regressions were used to identify factors associated with reporting errors. We also examined the associations of self-reported and measured BMI with obesity-related health outcomes using multivariable logistic regressions, with hypertension as an example, to evaluate the impact of misreporting. RESULTS:We found that self-reported and measured values were highly correlated among all and when stratified by participants' characteristics (intraclass correlation coefficients ??0.99, 0.84, and 0.96 for weight, height, and BMI, respectively). The agreement between BMI categories (normal, overweight and obese) based on self-reported and measured data was excellent (kappa?=?0.81). Women who were older, never smoked, had higher grade tumors, or had greater BMI tended to have overestimated BMI calculated from self-reported weight and height. The BMI-hypertension association was similar using self-reported (OR per 5 kg/m2 increase 1.63; 95% CI 1.27-2.10) and measured BMI (1.58; 95% CI 1.23-2.03). CONCLUSIONS:Self-reported weight, height, and BMI were reasonably accurate in the WCHFS. IMPLICATIONS FOR CANCER SURVIVORS:Our study supports the use of these self-reported values among cancer survivors when direct measurements are not possible.
Project description:OBJECTIVE:This study aims to identify determinants of dietary behaviour in wheelchair users with spinal cord injury or lower limb amputation, from the perspectives of both wheelchair users and rehabilitation professionals. The findings should contribute to the field of health promotion programs for wheelchair users. METHODS:Five focus groups were held with wheelchair users (n = 25), and two with rehabilitation professionals (n = 11). A thematic approach was used for data analysis in which the determinants were categorized using an integrated International Classification of Functioning, Disability and Health and Attitude, Social influence and self-Efficacy model. RESULTS:Reported personal factors influencing dietary behaviour in wheelchair users were knowledge, boredom, fatigue, stage of life, habits, appetite, self-control, multiple lifestyle problems, intrinsic motivation, goal setting, monitoring, risk perception, positive experiences, suffering, action planning, health condition, function impairments, attitude and self-efficacy. Reported environmental factors influencing dietary behaviour in wheelchair users were unadjusted kitchens, monitoring difficulties, eating out, costs, unfavourable food supply, nutrition education/counselling, access to simple healthy recipes, eating together, cooking for others, and awareness and support of family and friends. CONCLUSIONS:Important modifiable determinants of dietary behaviour in wheelchair users that might be influenced in lifestyle interventions are knowledge, fatigue, habits, self-control, intrinsic motivation, risk perception, attitude and self-efficacy. It is recommended to involve relatives, since they appear to significantly influence dietary behaviour.
Project description:BACKGROUND/OBJECTIVES:Bland-Altman methods for assessing the agreement between two measures are highly cited. However, these methods may often not be used to assess agreement, and when used, they are not always presented or interpreted correctly. Our objective was to evaluate the use and the quality of reporting of Bland-Altman analyses in studies that compare self-reported with measured weight and height. METHODS:We evaluated the use of Bland-Altman methods in 394 published articles that compared self-reported and measured weight and height data for adolescents or adults. Six reporting criteria were developed: assessment of the normality of the distribution of differences, a complete and correctly labeled Bland-Altman plot displaying the mean difference and limits of agreement (LOA), numerical values and confidence intervals, standard errors, or standard deviations for mean difference, numerical values of LOA, confidence intervals for LOA, and prespecified criteria for acceptable LOA. RESULTS:Only 72/394 (18%) studies comparing self-reported with measured weight and height or BMI used some form of Bland-Altman analyses. No study using Bland-Altman analyses satisfied more than four of the six criteria. Of the 72 studies, 64 gave mean differences along with confidence intervals or standard deviations, 55 provided complete Bland-Altman plots that were appropriately labeled and described, 37 provided numerical values for LOA, 4 reported that they examined the normality of the distribution of differences, 3 provided confidence intervals for LOA, and 3 had prespecified criteria for agreement. CONCLUSIONS:Bland-Altman methods appear to be infrequently used in studies comparing measured with self-reported weight, height, or BMI, and key information is missing in many of those that do use Bland-Altman methods. Future directions would be defining acceptable LOA values and improving the reporting and application of Bland-Altman methods in studies of self-reported anthropometry.
Project description:Objective: This paper reports the iterative redesign, feasibility and usability of the Comprehensive Mobile Assessment of Pressure (CMAP) system's mobile app used by Veterans with SCI.Design: This three-year, multi-staged study used a mixed-methods approach.Setting: Minneapolis VA Health Care System, Minneapolis, Minnesota.Participants: Veterans with spinal cord injury (N?=?18).Interventions: Veterans with spinal cord injury engaged in iterative focus groups and personal interviews, sharing their needs and desires for the CMAP app redesign. App developers used these data for the redesign. The redesigned CMAP app was tested for six-weeks in users' homes.Outcome Measures: Quantitative (surveys) and qualitative (interviews) methods measured feasibility for self-management of seating pressure. Qualitative data were audio recorded, transcribed, anonymized, and coded. Survey data were analyzed using summary statistics.Results: After the CMAP system's redesign, the in-home use interview found: (1) any tool that can assist in prevention and monitoring of skin ulcers is important; (2) the desired key features are present in the app; (3) the main barrier to CMAP use was inconsistent functionality; (4) when functioning as expected, the live pressure map was the central feature, with reminders to weight shift also of high importance. The survey found: power wheelchair users tended to score closer than manual wheelchair users to the positive response end ranges on two separate surveys.Conclusions: Overall both the power and manual wheelchair users reported that they wanted to use the system, felt confident using the system, and that the functions of the system were well integrated.
Project description:OBJECTIVE:The aim of this study was to compare national estimates of self-reported and measured height and weight, BMI, and obesity prevalence among adults from US surveys. METHODS:Self-reported height and weight data came from the National Health and Nutrition Examination Survey (NHANES), the National Health Interview Survey, and the Behavioral Risk Factor Surveillance System for the years 1999 to 2016. Measured height and weight data were available from NHANES. BMI was calculated from height and weight; obesity was defined as BMI???30. RESULTS:In all three surveys, mean self-reported height was higher than mean measured height in NHANES for both men and women. Mean BMI from self-reported data was lower than mean BMI from measured data across all surveys. For women, mean self-reported weight, BMI, and obesity prevalence in the National Health Interview Survey and Behavioral Risk Factor Surveillance System were lower than self-report in NHANES. The distribution of BMI was narrower for self-reported than for measured data, leading to lower estimates of obesity prevalence. CONCLUSIONS:Self-reported height, weight, BMI, and obesity prevalence were not identical across the three surveys, particularly for women. Patterns of misreporting of height and weight and their effects on BMI and obesity prevalence are complex.
Project description:BACKGROUND: Cultural pressures to be thin and tall are postulated to cause people to misreport their body weight and height towards more socially normative (i.e., desirable) values, but a paucity of direct evidence supports this idea. We developed a novel non-linear approach to examining weight, height, and BMI misreporting biases and used this approach to examine the association between socially non-normative weight and misreporting biases in adults. METHODS: The Survey of Lifestyles, Attitudes, and Nutrition 2007 (SLÁN 2007), a nationally representative survey of the Republic of Ireland (N = 1942 analyzed) was used. Self-reported weight (height) was classified as under-reported by ? 2.0 kg (2.0 cm), over-reported by ? 2.0 kg (2.0 cm), or accurately reported within 2.0 kg (2.0 cm) to account for technical errors of measurement and short-term fluctuations in measured weight (height). A simulation strategy was used to define self-report-based BMI as under-estimated by more than 1.40 kg/m2, over-estimated by more than 1.40 kg/m2, or accurately estimated within 1.40 kg/m2. Patterns of biases in self-reported weight, height, and BMI were explored. Logistic regression was used to identify factors associated with mis-estimated BMI and to calculate adjusted odds ratios (AOR) and 99% confidence intervals (99%CI). RESULTS: The patterns of bias contributing the most to BMI mis-estimation were consistently, in decreasing order of influence, (1) under-reported weight combined with over-reported height, (2) under-reported weight with accurately reported height, and (3) accurately reported weight with over-reported height. Average bias in self-report-based BMI was -1.34 kg/m2 overall and -0.49, -1.33, and -2.66 kg/m2 in normal, overweight, and obese categories, respectively. Despite the increasing degree of bias with progressively higher BMI categories, persons describing themselves as too heavy were, within any given BMI category, less likely to have under-estimated BMI (AOR 0.5, 99%CI: 0.3-0.8, P < 0.001), to be misclassified in a lower BMI category (AOR 0.3, 99%CI: 0.2-0.5, P < 0.001), to under-report weight (AOR 0.5, 99%CI: 0.3-0.7, P < 0.001), and to over-report height (OR 0.7, 99%CI: 0.6-1.0, P = 0.007). CONCLUSIONS: A novel non-linear approach to examining weight, height, and BMI misreporting biases was developed. Perceiving oneself as too heavy appears to reduce rather than exacerbate weight, height, and BMI misreporting biases.
Project description:INTRODUCTION:Self-reported height and weight may lead to inaccurate estimates of associations between BMI and health indicators. The purpose of this study is to assess anthropometric misreporting in emerging adults, compare weight classification by self-reported and direct measures, and examine associations of self-reported and direct measures with cardiometabolic biomarkers. METHODS:Self-reported and directly measured height and weight were obtained in five waves of a nationally representative cohort study of U.S. tenth graders (n=2,785) conducted in 2010-2016; data were analyzed in 2018. Cardiometabolic biomarkers were assessed in three waves in a systematically recruited subsample (n=567). Pearson correlations (r) and Lin's concordance correlations (?c) evaluated misreporting. Gwet agreement coefficient-1 evaluated weight classification agreement by self-reported and direct measures. Generalized estimating equations examined associations of cardiometabolic biomarkers with self-reported and direct measures. RESULTS:Participants overreported height by 1.0-1.7 cm and underestimated weight by 0.6-1.7 kg. Self-reported BMI was 0.6-1.0 lower than measured. Self-reported and measured height, weight, and BMI were strongly correlated (r=0.88-0.97, 0.86-0.98, and 0.65-0.96, respectively) and concordant (?c=0.82-0.96, 0.94-0.97, and 0.65-0.95, respectively). Agreement of weight classification by self-reported and direct measures ranged from Gwet agreement coefficient-1=0.79-0.94. Associations of ten cardiometabolic biomarkers with self-reported BMI, measured BMI, and waist circumference were similar in magnitude, direction, and precision. CONCLUSIONS:Self-reported and measured BMI were strongly correlated and concordant, providing substantial to near-perfect agreement in weight classification. Findings suggest self-reported BMI in U.S. emerging adults provides nearly identical estimates of associations with cardiometabolic biomarkers.
Project description:BACKGROUND: In population studies, body mass index (BMI) is generally calculated from self-reported body weight and height. The self-report of these anthropometrics is known to be biased, resulting in a misclassification of BMI status. The aim of our study is to evaluate the accuracy of self-reported weight, height and waist circumference among a Dutch overweight (Body Mass Index [BMI] > or = 25 kg/m2) working population, and to determine to what extent the accuracy was moderated by sex, age, BMI, socio-economic status (SES) and health-related factors. METHODS: Both measured and self-reported body weight and body height were collected in 1298 healthy overweight employees (66.6% male; mean age 43.9 +/- 8.6 years; mean BMI 29.5 +/- 3.4 kg/m2), taking part in the ALIFE@Work project. Measured and self-reported waist circumferences (WC) were available for a sub-group of 250 overweight subjects (70.4% male; mean age 44.1 +/- 9.2 years; mean BMI 29.6 +/- 3.0 kg/m2). Intra Class Correlation (ICC), Cohen's kappa and Bland Altman plots were used for reliability analyses, while linear regression analyses were performed to assess the factors that were (independently) associated with the reliability. RESULTS: Body weight was significantly (p < 0.001) under-reported on average by 1.4 kg and height significantly (p < 0.001) over-reported by 0.7 cm. Consequently, BMI was significantly (p < 0.001) under-reported by 0.7 kg/m2. WC was significantly (p < 0.001) over-reported by 1.1 cm. Although the self-reporting of anthropometrics was biased, ICC's showed high concordance between measured and self-reported values. Also, substantial agreement existed between the prevalences of BMI status and increased WC based on measured and self-reported data. The under-reporting of BMI and body weight was significantly (p < 0.05) affected by measured weight, height, SES and smoking status, and the over-reporting of WC by age, sex and measured WC. CONCLUSION: Results suggest that self-reported BMI and WC are satisfactorily accurate for the assessment of the prevalence of overweight/obesity and increased WC in a middle-aged overweight working population. As the accuracy of self-reported anthropometrics is affected by measured weight, height, WC, smoking status and/or SES, results for these subgroups should be interpreted with caution. Due to the large power of our study, the clinical significance of our statistical significant findings may be limited. TRIAL REGISTRATION: ISRCTN04265725.
Project description:BACKGROUND: Validation studies of self-reported BMI are limited to populations in high-income countries or urban settings. Here, we assess the accuracy of two proxy measures of measured height, weight and BMI - self-reported values and the Stunkard figure scale - in a semi-rural population in Guatemala. METHODS: Self-reported values and Stunkard figure selection were elicited prior to biometric measurements from a total of 175 non-pregnant women recruited based on a stratified random sample of households, with 92 women providing full data for validation across measures. RESULTS: 86.3% of participants self-reported weight and 62.3% height. Among those responding, self-reported weight is highly accurate though lower relationships for height contribute to error in reported BMI. The Stunkard scale has a higher response rate (97.1%) and while less accurate in predicting BMI values, more accurately predicts BMI categories. CONCLUSIONS: Self-reported measures are more accurate than the Stunkard scale in estimating BMI values, while the latter is more accurate in estimating BMI categories. High non-response rates and lower correlations between reported and measured height caution against using self-reported biometric data other than raw weight in low-resource settings.
Project description:To compare the effectiveness of 2 home-based behavioral interventions for wheelchair users to promote exercise adoption and maintenance over 12 months.Randomized controlled trial, with participants stratified into groups based on disability type (stable, episodic, progressive) and support partner availability.Exercise occurred in participant-preferred locations (eg, home, recreation center), with physiological data collected at a university-based exercise laboratory.Inactive wheelchair users (N=128; 64 women) with sufficient upper arm mobility for arm-based exercise were enrolled. Participants on average were 45 years of age and lived with their impairment for 22 years, with spinal cord injury (46.1%) most commonly reported as causing mobility impairment.Both groups received home-based exercise interventions. The staff-supported group (n=69) received intensive exercise support, while the self-guided group (n=59) received minimal support. Both received exercise information, resistance bands, instructions to self-monitor exercise, regularly scheduled phone calls, and handwritten cards.The primary outcome derived from weekly self-reported exercise. Secondary outcomes included physical fitness (aerobic/muscular) and predictors of exercise participation.The staff-supported group reported significantly greater exercise (?17min/wk) than the self-guided group over the year (t=10.6, P=.00), with no significant between-group difference in aerobic capacity (t=.76, P=.45) and strength (t=1.5, P=.14).Although the staff-supported group reported only moderately more exercise, the difference is potentially clinically significant because they also exercised more frequently. The staff-supported approach holds promise for encouraging exercise among wheelchair users, yet additional support may be necessary to achieve more exercise to meet national recommendations.