Interrater reliability of novice examiners using A-mode ultrasound and skinfolds to measure subcutaneous body fat.
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ABSTRACT:
SUBMITTER: Wagner DR
PROVIDER: S-EPMC7735566 | biostudies-literature | 2020
REPOSITORIES: biostudies-literature
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Interrater reliability of novice examiners using A-mode ultrasound and skinfolds to measure subcutaneous body fat.
Wagner Dale R DR Teramoto Masaru M
PloS one 20201214 12
Examiners with minimal training and skill are often called upon to make body composition assessments using field methods. This study compared the interrater reliability of novice examiners for the skinfold (SKF) and A-mode ultrasound (US) methods of body composition assessment. Undergraduate Kinesiology majors (48 males, 32 females) with minimal training took both SKF and US measurements at three sites (males: chest, abdomen, thigh; females: triceps, suprailiac, thigh). Interrater reliability wa ...[more]
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Project description:PurposeThis study compared subcutaneous adipose tissue (SAT) measurements using a skinfold caliper and Renco Lean-Meater Series 12 A-mode portable ultrasound scanner (A-US). It aimed to assess their inter- and intra-rater reliability and measure the agreement between both methods.MethodsEighty-four volunteers of different fitness levels were divided into three groups by Ʃ6 skinfolds: G1 ≤ 55 mm (n = 33 males); G2 > 55 mm (n = 32 males); G3 = 98.0 ± 52.3 mm (n = 19 females). Triceps, subscapular, biceps, iliac crest, supraspinal, abdominal, front thigh and medial calf were assessed by ultrasound and skinfolds. Two technicians for both tools performed triplicate measures. Intraclass correlation (ICC), technical error of measurement (TEM) and coefficients of variation (CVs) were applied for test-retest and inter-rater reliability. Non-Parametric statistics were used in order to establish possible statistical differences and correlation between skinfolds thickness and uncompressed subcutaneous adipose tissue thickness from ultrasound. The amount of agreement between both methods was assessed with Lin's coefficient and a scatterplot of all site locations. A Bland-Altman plot was constructed to establish limits of agreement between groups and regression analysis was employed to assess the ability of skinfolds to explain the variance of ultrasound.ResultsTest-retest ICC for skinfolds and ultrasound were higher than 0.989 and 0.793, respectively. Inter-rater ICC for skinfolds was 0.999 with a 95% CI of 0.995 to 0.999 and for ultrasound was 0.755 with a much larger 95% CI of 0.622 to 0.841. TEMs (> 8.50%) and CVs (> 6.72%) compromised ultrasound reliability. Statistical differences were found in most of the analysed anatomical sites (p < 0.001) except in biceps G2 (Z = -1.150, p = 0.25) and G3 (Z = -1.309, p = 0.19). Good correlations (r > 0.7, p ≤ 0.05) were reported at almost all anatomical sites and groups except for biceps (G1: Rho = 0.26, p = 0.140) and abdominal (G2: Rho = -0.16, p = 0.38; G3: Rho = 0.43, p = 0.068). Lin's concordance correlation coefficient registered low values of agreement between skinfolds and A-mode ultrasound (ranged from-0.009-0.646). The scatterplot and the estimated regression line drawn through the midst of all anatomical sites of the whole sample had a slope of 0.51 and R2 adjusted = 0.62 was obtained. The combined analysis between the Bland-Altman plot and the linear regression showed that specifically in the G2 and G3 groups, as the SAT increases the differences between skinfolds and ultrasounds measurements also increases.ConclusionsThe Renco Lean-Meater ultrasound is not interchangeable with skinfold measures. Its utility is questionable, particularly for assessing SAT in active adult populations. Its poor test-retest and inter-rater reliability as well as the lack of agreement when compared to the skinfolds would exclude the free use of the A-mode ultrasound scanner in its hypothetical replacing of the classical calipers.
| S-EPMC6264474 | biostudies-literature
Project description:ObjectiveTo test the interrater reliability of examiners performing the prone instability test (PIT), a clinical test proposed to identify lumbar shear instability.DesignCross-sectional test-retest design examining individuals with mechanical low back pain (LBP).SettingUniversity-based musculoskeletal analysis laboratory.ParticipantsIndividuals (N=30) with mechanical LBP recruited from community sources in a metropolitan region.InterventionsNot applicable.Main outcome measuresRepeated measures of a clinical examination test proposed to identify lumbar shear instability.ResultsInterrater reliability of examiners' judgments of PIT results were indexed with percentage of agreement and κ statistic. Examiners obtained 63% agreement and κ of .10 (95% confidence interval, -.27 to .47). Adjusted κ values based on prevalence and bias indexes were calculated to evaluate the effect on κ. The prevalence index associated with examiner judgments of the PIT was .43, and bias index was .03. The prevalence-adjusted bias-adjusted κ value was slightly higher than the unadjusted κ value (κ=.27; 95% confidence interval, -.08 to .61).ConclusionsResults of our study are not consistent with those of previous studies examining the reliability of therapists performing the PIT. We conclude that examiners do not attain acceptable interrater reliability when performing procedures for the PIT based on the information currently provided in the literature. Based on our experience, we suggest further exploration, standardization, and clarification of procedural details to improve therapists' ability to conduct the PIT on individuals with LBP.
| S-EPMC3104326 | biostudies-literature
Project description:Caliper and ultrasound (US) are used to measure subcutaneous fat tissue depth (SFT) and then to calculate total body fat. There is no evidence-based recommendation as to whether caliper or US are equally accurate. The aim of this paper was therefore to compare reliability of both methods. In this methodical study, 54 participants (BMI: 24.8 ± 3.5 kg/m2; Age: 43.2 ± 21.7 years) were included. Using systematic body mapping, the SFT of 56 areas was measured. We also analyzed 4 body sites via MRI. A comparison between caliper and US detected clear differences in mean SFT of all areas (0.83 ± 0.33 cm vs. 1.14 ± 0.54 cm; p < 0.001) showing moderate reliability (ICC 0.669, 95%CI: 0.625-0.712). US and MRI revealed in the abdominal area a SFT twice as thick as caliper (2.43 ± 1.36 cm vs. 2.26 ± 1.32 cm vs. 1.15 ± 0.66 cm; respectively). Caliper and US revealed excellent intrarater (ICC caliper: 0.944, 95%CI: 0.926-0.963; US: 0.934, 95%CI: 0.924-0.944) and good interrater reliability (ICC caliper: 0.794, 95%CI: 0.754-0.835; US: 0.825, 95%CI: 0.794-0.857). Despite the high reliability in measuring SFT that caliper and US show, our comparison of the two methods yielded clear differences in SFT, particularly in the abdominal area. In accuracy terms, US is preferable for most mapping areas.
| S-EPMC9500055 | biostudies-literature
Project description:IntroductionFat is a metabolic fuel, but excess body fat is ballast mass, and therefore, many elite athletes reduce body fat to dangerously low levels. Uncompressed subcutaneous adipose tissue (SAT) thickness measured by brightness-mode ultrasound (US) provides an estimate of body fat content.MethodsThe accuracy for determining tissue borders is about 0.1-0.2 mm and reliability (experienced measurers) was within?±?1.4 mm (95% limit of agreement, LOA). We present here inter- and intra-measurer scores of three experienced US measurers from each of the centres C1 and C2, and of three novice measurers from each of the centres C3-C5. Each of the five centres measured 16 competitive adult athletes of national or international level, except for one centre where the number was 12. The following sports were included: artistic gymnastics, judo, pentathlon, power lifting, rowing, kayak, soccer, tennis, rugby, basketball, field hockey, water polo, volleyball, American football, triathlon, swimming, cycling, long-distance running, mid-distance running, hurdles, cross-country skiing, snowboarding, and ice hockey. SAT contour was detected semi-automatically: typically, 100 thicknesses of SAT at a given site (i.e., in a given image), with and without fibrous structures, were measured.ResultsAt SAT thickness sums DI (of eight standardised sites) between 6.0 and 70.0 mm, the LOA of experienced measurers was 1.2 mm, and the intra-class correlation coefficient ICC was 0.998; novice measurers: 3.1 mm and 0.988. Intra-measurer differences were similar. The median DI value of all 39 female participants was 51 mm (11% fibrous structures) compared to 17 mm (18%) in the 37 male participants.DiscussionDI measurement accuracy and precision enables detection of fat mass changes of approximately 0.2 kg. Such reliability has not been reached with any other method. Although females' median body mass index and mass index were lower than those of males, females' median DI was three times higher, and their percentage of fibrous structures was lower. The standardised US method provides a highly accurate and reliable tool for measuring SAT and thus changes in body fat, but training of measurers is important.
| S-EPMC7018793 | biostudies-literature
Project description:BackgroundInterrater reliability, aka intercoder reliability, is defined as true agreement between raters, aka coders, without chance agreement. It is used across many disciplines including medical and health research to measure the quality of ratings, coding, diagnoses, or other observations and judgements. While numerous indices of interrater reliability are available, experts disagree on which ones are legitimate or more appropriate. Almost all agree that percent agreement (ao), the oldest and the simplest index, is also the most flawed because it fails to estimate and remove chance agreement, which is produced by raters' random rating. The experts, however, disagree on which chance estimators are legitimate or better. The experts also disagree on which of the three factors, rating category, distribution skew, or task difficulty, an index should rely on to estimate chance agreement, or which factors the known indices in fact rely on. The most popular chance-adjusted indices, according to a functionalist view of mathematical statistics, assume that all raters conduct intentional and maximum random rating while typical raters conduct involuntary and reluctant random rating. The mismatches between the assumed and the actual rater behaviors cause the indices to rely on mistaken factors to estimate chance agreement, leading to the numerous paradoxes, abnormalities, and other misbehaviors of the indices identified by prior studies.MethodsWe conducted a 4 × 8 × 3 between-subject controlled experiment with 4 subjects per cell. Each subject was a rating session with 100 pairs of rating by two raters, totaling 384 rating sessions as the experimental subjects. The experiment tested seven best-known indices of interrater reliability against the observed reliabilities and chance agreements. Impacts of the three factors, i.e., rating category, distribution skew, and task difficulty, on the indices were tested.ResultsThe most criticized index, percent agreement (ao), showed as the most accurate predictor of reliability, reporting directional r2 = .84. It was also the third best approximator, overestimating observed reliability by 13 percentage points on average. The three most acclaimed and most popular indices, Scott's π, Cohen's κ and Krippendorff's α, underperformed all other indices, reporting directional r2 = .312 and underestimated reliability by 31.4 ~ 31.8 points. The newest index, Gwet's AC1, emerged as the second-best predictor and the most accurate approximator. Bennett et al's S ranked behind AC1, and Perreault and Leigh's Ir ranked the fourth both for prediction and approximation. The reliance on category and skew and failure to rely on difficulty explain why the six chance-adjusted indices often underperformed ao, which they were created to outperform. The evidence corroborated the notion that the chance-adjusted indices assume intentional and maximum random rating while the raters instead exhibited involuntary and reluctant random rating.ConclusionThe authors call for more empirical studies and especially more controlled experiments to falsify or qualify this study. If the main findings are replicated and the underlying theories supported, new thinking and new indices may be needed. Index designers may need to refrain from assuming intentional and maximum random rating, and instead assume involuntary and reluctant random rating. Accordingly, the new indices may need to rely on task difficulty, rather than distribution skew or rating category, to estimate chance agreement.
| S-EPMC9426226 | biostudies-literature
Project description:The present Systematic Review with Meta-analysis study aimed to evaluate the validity and reliability of the Portable A-mode Ultrasound (P-US) for measuring body fat percentage (BF%). Only studies with participants of both genders which had assessed BF% using P-US compared to the reference standard were selected. Publications up until May 31, 2022 were searched in the MEDLINE, COCHRANE, Science Direct, Web of Science, LILACS, SciELO, PEDro, SPORT Discus, CINAHL and SCOPUS databases. QUADAS-2 was used to assess the risk of bias in the validity studies and QAREL was used for the methodological quality of reliability studies. The JAMOVI software program synthesized the results, from which the Pearson Correlation Coefficient (r) or the square root of the Multiple Linear Regression Determination Coefficient (R2) were extracted for the validity studies, and the Mean of Errors of the Bland-Altman Test (ME) and the Confidence Interval (95%CI) with Upper and Lower Limits for the reliability studies. A total of 13 studies were included, generating 26 results for the quantitative synthesis, 14 for validity and 12 for reliability. Regarding the validity results, a strong correlation was identified between the equipment (r = 0.870 [0.845-0.895], P<0.001), with moderate and true heterogeneity (I2 = 53.47%, P = 0.003), presenting publication bias. A small effect size was identified regarding the reliability results, overestimating the results due to chance between the devices (ME = 0.207 [-0.798-1.212], P = 0.686), with low heterogeneity also due to chance (I2 = 19.44%, P = 0.253), with no publication bias. All of the evaluated studies showed some violation of the instruments, confirming the high risk of bias and the low methodological quality. There is concern with heterogeneity for the validity results explained by the subgroups' analysis. The P-US associated with anthropometric perimeters satisfactorily measures the BF% with samples greater than 100 participants, and males. The results in the reliability assessment show high agreement and high variability, greatly expanding the confidence interval, which should be viewed with reservations. This review received financial support from the Brazilian Air Force. The study was registered with PROSPERO under the number CRD42020166617.
| S-EPMC10852247 | biostudies-literature
Project description:Background/objectivesSeveral studies have addressed the validity of ultrasound (US) for body composition assessment, but few have evaluated its reliability. This study aimed to determine the reliability of percent body fat (%BF) estimates using A-mode US in a heterogeneous sample.Subjects/methodsA group of 144 healthy adults (81 men and 63 women), 30.4 (10.1) years (mean (SD)), BMI 24.6 (4.7) kg/m2, completed 6 consecutive measurements of the subcutaneous fat layer thickness at 8 anatomical sites. The measurements were done, alternatively, by two testers, using a BodyMetrix™ instrument. To compute %BF, 4 formulas from the BodyView™ software were applied: 7-sites Jackson and Pollock, 3-sites Jackson and Pollock, 3-sites Pollock, and 1-point biceps.ResultsThe formula with the most anatomic sites provided the best reliability quantified by the following measures: intraclass correlation coefficient (ICC) = 0.979 for Tester 1 (T1) and 0.985 for T2, technical error of measurement (TEM) = 1.07% BF for T1 and 0.89% BF for T2, and minimal detectable change (MDC) = 2.95% BF for T1, and 2.47% BF for T2. The intertester bias was -0.5% BF, whereas the intertester ICC was 0.972. The intertester MDC was 3.43% BF for the entire sample, 3.24% BF for men, and 3.65% BF for women.ConclusionsA-mode US is highly reliable for %BF assessments, but it is more precise for men than for women. Examiner performance is a source of variability that needs to be mitigated to further improve the precision of this technique.
| S-EPMC7943421 | biostudies-literature
Project description:PURPOSE:Despite their widespread use in research and fitness settings, Durnin and Womersley's (DW) 1974 prediction equations using skinfold thickness to estimate body fat percent by hydrodensitometry have not been systematically evaluated in racial or ethnic groups using body fat percent measured by dual-energy x-ray absorptiometry (%BF(DXA)) as the standard. METHODS:This cross-sectional, population-based study examined whether the DW skinfold equations predict %BF(DXA) in a large, multiracial sample. Four skinfold measures (biceps, triceps, subscapular, and suprailiac), other clinical anthropometrics, and %BF(DXA) were obtained from 1675 healthy adults, age 18-110 yr, who were classified into four racial or ethnic categories: Caucasian, African American, Hispanic, or Asian. Predicted body fat percent using DW equations was compared with %BF(DXA) and evaluated within race/ethnicity- and sex-specific groups. RESULTS:Mean body fat percent predicted by DW equations was significantly different from %BF(DXA) in four of eight race/ethnicity- and sex-specific groups, particularly in Asian women and African American men (3.3 and 2.4 percentage point overestimates, respectively, P < 0.0001). New linear regression equations were developed estimating %BF(DXA) specific to each race/ethnicity and sex group, using the original DW skinfold sites. Body weight, height, and waist circumference independently predicted fat percent and were also included in the new equations. CONCLUSIONS:The 1974 DW equations did not predict %BF(DXA) uniformly in all races or ethnicities. Using %BF(DXA) as the criterion measure, the original DW skinfold equations have been updated specific to sex and race/ethnicity while maintaining the DW options for a minimalistic model using fewer predictors.
| S-EPMC3308342 | biostudies-literature
Project description:This study assesses the interrater reliability of Ayurvedic pulse (nadi), tongue (jivha), and body constitution (prakriti) assessments. Fifteen registered Ayurvedic doctors with 3-15 years of experience independently examined twenty healthy subjects. Subjects completed self-assessment questionnaires and software analyses for prakriti assessment. Weighted kappa statistics for all 105 pairs of doctors were computed for the pulse, tongue, and prakriti data sets. According to the Landis-Koch scale, the pairwise kappas ranged from poor to slight, slight to fair, and fair to moderate for pulse, tongue, and prakriti assessments, respectively. The average pairwise kappa for pulse, tongue, and prakriti was 0.07, 0.17, and 0.28, respectively. For each data set and pair of doctors, the null hypothesis of random rating was rejected for just twelve pairs of doctors for prakriti, one pair of doctors for pulse examination, and no pairs of doctors for tongue assessment. Thus, the results demonstrate a low level of reliability for all types of assessment made by doctors. There was significant evidence against random rating by software and questionnaire use and by the diagnosis preferred by the majority of doctors. Prakriti assessment appears reliable when questionnaire and software assessment are used, while other diagnostic methods have room for improvement.
| S-EPMC3803118 | biostudies-literature
Project description:IntroductionClinical clerkships that rely on community preceptors as faculty and assessors are challenged by the variability in their assessments of student performance. This workshop was designed to improve the interrater reliability of preceptors' assessment of student performance.MethodsThis workshop uses a series of videos showing standardized student interactions with standardized patients and a preceptor. The videos feature a borderline satisfactory student-patient encounter and a superior student encounter. For each case, there is a video of the student providing an oral presentation of the encounter to a preceptor. The concept of a plus/delta card is also presented. Participants are asked to note positive elements of the interactions and elements needing improvement on the plus/delta card while watching the videos. Next, participants share their assessment of the students with the group using an audience response system. Group discussion allows for consensus and leads to decreased variation in preceptor assessments of each student's performance. This workshop has been delivered to preceptors in our institution as a 1-hour workshop. Additionally, a version has been presented twice at national medical teaching conferences as a faculty development workshop, instructing faculty how to facilitate the workshop.ResultsParticipant evaluations from the workshop show an increase in preceptors' awareness of specific student behaviors to observe as well as increased confidence with assessing more consistently across various student performances.DiscussionUsing videos with standardized patients, students, and preceptors demonstrating various qualities of performance is effective in improving precision in preceptors' assessment of students in clinical settings.
| S-EPMC6338197 | biostudies-literature