Reliability, Measurement Error, and Responsiveness of the Voice Handicap Index: A Systematic Review and Meta-analysis.

OBJECTIVE: To analyze the reliability, measurement error, and responsiveness of the Voice Handicap Index (VHI) for measuring voice handicap in individuals with voice disorders. METHODS: This systematic review followed the recommendations of the COnsensus-based Standards for the Selection of Health Measurement INstruments. Studies that validated the VHI, analyzed the measurement properties of reliability, measurement error, or responsiveness, and had dysphonic individuals as the study population were included. The following electronic databases were searched: Cochrane Library, EMBASE, LILACS, PubMed, Scopus, and Web of Science. The manual search was carried out on gray literature in the Biblioteca Digital Brasileira de Teses e Dissertações and ProQuest Dissertation & Theses, in addition to mapping citations and consulting an expert in the field. Evidence selection, data extraction, risk of bias analysis, certainty of evidence, and good psychometric measurements were performed by two blinded and independent reviewers. A meta-analysis was performed using Fisher's transformed r-to-z correlation coefficient and standardized mean difference. Heterogeneity was calculated using Tau² and I² statistical tests in JAMOVI 2.3.2 software. RESULTS: Eighty studies were included in the meta-analysis. When assessing the risk of bias, most studies were classified as inadequate during the reliability and measurement error stages. In the responsiveness stage, they were classified as doubtful in the sensitivity and specificity sub-boxes and good in the comparison sub-box with a gold standard instrument. For psychometric properties, most studies were classified as indeterminate in terms of both reliability and responsiveness. In test-retest reliability and responsiveness, the average outcome differed significantly from zero, indicating agreement between the test and retest moments and a significant reduction in the VHI score after intervention. Considering certainty of the evidence, the level of evidence was very low in both the reliability and responsiveness stages. The analyzed studies did not evaluate observational errors, and hence, they were not considered in this review. CONCLUSION: The VHI proved to be reliable and responsive in measuring voice handicap. However, it should be used with caution, as there is heterogeneity, a risk of bias, and no adherence to the analysis of observational error.

Is leaf fluctuating asymmetry related to plant and leaf size in Miconia albicans, a common Melastomataceae species? / A assimetria flutuante de folhas está relacionada ao tamanho da planta e da folha em um arbusto de savana neotropical?

Fluctuating asymmetry, defined as random differences between the two sides of a symmetrical structure, has been often related to development stress in both plants and animals. In plants, leaf fluctuating asymmetry has been related to stresses such as pollution and fire and may also be related to leaf growth and herbivory rates. We assessed whether leaf fluctuating asymmetry is related to plant and leaf size in Miconia albicans (Sw.) Triana (Melastomataceae), a common multi-stem Neotropical shrub, in a Brazilian savanna area. We collected 15 leaves from each of 70 individuals, and measured fluctuating asymmetry as the difference in area between the right and left sides of the leaves using the central vein as reference. To avoid spurious results due to measurement error, the division along the central vein was performed independently by three researchers. We also measured the basal area and height of each stem of the plant individuals. We used linear models to assess the relations between leaf fluctuating asymmetry, plant size and leaf size. No consistent relations were observed between leaf fluctuating asymmetry and plant size, as the analyses performed on the fluctuating asymmetry values obtained by the different researchers showed different results. However, relative fluctuating asymmetry values, obtained by dividing the fluctuating asymmetry by the total leaf area, tended to be smaller in larger leaves. It thus appears that, in the study species, fluctuating asymmetry is related to the developmental conditions faced by the individual leaves and not by the plant as a whole.

A assimetria flutuante, definida como diferenças aleatórias entre os dois lados de uma estrutura simétrica, tem sido frequentemente relacionada ao estresse de desenvolvimento em plantas e animais. Nas plantas, a assimetria flutuante foliar tem sido relacionada a estresses como poluição e fogo e também pode estar relacionada ao crescimento foliar e taxas de herbivoria. Nós avaliamos se a assimetria flutuante foliar está relacionada ao tamanho da planta e da folha em Miconia albicans (Sw.) Triana (Melastomataceae), um arbusto neotropical multicaule comum, em uma área de Cerrado. Coletamos 15 folhas de cada um dos 70 indivíduos e medimos a assimetria flutuante como a diferença de área entre os lados direito e esquerdo das folhas usando a nervura central como referência. Para evitar resultados espúrios devido ao erro de medição, a separação ao longo da nervura centra foi feita independentemente por três pesquisadoras/es. Também medimos a área basal e a altura de cada caule de cada planta. Usamos modelos lineares para avaliar as relações entre assimetria flutuante foliar, tamanho da planta e tamanho da folha. Não foram observadas relações consistentes entre a assimetria flutuante da folha e o tamanho da planta, pois as análises realizadas nos valores da assimetria flutuante obtidos pelas/os diferentes pesquisadoras/es mostraram resultados diferentes. No entanto, os valores de assimetria flutuante relativa, obtidos pela divisão da assimetria flutuante pela área foliar total, tenderam a ser menores nas folhas maiores. Assim, verifica-se que, na espécie estudada, a assimetria flutuante está relacionada às condições de desenvolvimento enfrentadas pelas folhas individuais e não pela planta como um todo.

Acute changes in serum and skeletal muscle steroids in resistance-trained men.

Introduction: Resistance exercise can significantly increase serum steroid concentrations after an exercise bout. Steroid hormones are involved in the regulation of several important bodily functions (e.g., muscle growth) through both systemic delivery and local production. Thus, we aimed to determine whether resistance exercise-induced increases in serum steroid hormone concentrations are accompanied by enhanced skeletal muscle steroid concentrations, or whether muscle contractions per se induced by resistance exercise can increase intramuscular steroid concentrations. Methods: A counterbalanced, within-subject, crossover design was applied. Six resistance-trained men (26 ± 5 years; 79 ± 8 kg; 179 ± 10 cm) performed a single-arm lateral raise exercise (10 sets of 8 to 12 RM - 3 min rest between sets) targeting the deltoid muscle followed by either squat exercise (10 sets of 8 to 12 RM - 1 min rest) to induce a hormonal response (high hormone [HH] condition) or rest (low hormone [LH] condition). Blood samples were obtained pre-exercise and 15 min and 30 min post-exercise; muscle specimens were harvested pre-exercise and 45 min post-exercise. Immunoassays were used to measure serum and muscle steroids (total and free testosterone, dehydroepiandrosterone sulfate, dihydrotestosterone, and cortisol; free testosterone measured only in serum and dehydroepiandrosterone only in muscle) at these time points. Results: In the serum, only cortisol significantly increased after the HH protocol. There were no significant changes in muscle steroid concentrations after the protocols. Discussion: Our study provides evidence that serum steroid concentration increases (cortisol only) seem not to be aligned with muscle steroid concentrations. The lack of change in muscle steroid after protocols suggests that resistance-trained individuals were desensitized to the exercise stimuli. It is also possible that the single postexercise timepoint investigated in this study might be too early or too late to observe changes. Thus, additional timepoints should be examined to determine if RE can indeed change muscle steroid concentrations either by skeletal muscle uptake of these hormones or the intramuscular steroidogenesis process.

Ultrastructural calibration model for proficiency testing.

Proficiency testing (PT) determines the performance of individual laboratories for specific tests or measurements and it is used to monitor the reliability of laboratories measurements. PT plays a highly valuable role as it provides objective evidence of the competence of the participant laboratories. In this paper, we propose a multivariate calibration model to assess equivalence among laboratories measurements in PT. Our method allows to deal with multivariate data, where the item under test is measured at different levels. Although intuitive, the proposed model is nonergodic, which means that the asymptotic Fisher information matrix is random. As a consequence, a detailed asymptotic analysis was carried out to establish the strategy for comparing the results of the participating laboratories. To illustrate, we apply our method to analyze the data from the Brazilian engine test group, PT program, where the power of an engine was measured by eight laboratories at several levels of rotation.

The video assistant referee (var) in soccer: where is the biomechanics? / árbitro assistente de vídeo (var) no futebol: onde está a biomecânica?

ABSTRACT The aim of this article is to explore the basic principles of Biomechanics in relation to the objective measurements carried out by the Video Assistant Referee (VAR) operators and systems in soccer. It was presented an overall framework about the determination of kinematical variables, the definition and the sources of error, the understanding of factors contributing to errors in VAR decisions, and prospects for future solutions. To exemplify these concepts, the offside rule was chosen as it offers numerous instances of tools aiding for accurate measurements. Based on consolidated procedures of literature, a discussion about the actual challenges and an suggestions for a fully comprehension and improvement of VAR were provided.

RESUMO O objetivo deste artigo foi explorar os princípios básicos da Biomecânica em relação às medições objetivas realizadas pelos operadores e sistemas do Árbitro Assistente de Vídeo (VAR) no futebol. Foi apresentado uma estrutura geral sobre a determinação das variáveis ​​cinemáticas, a definição e as fontes de erro, a compreensão dos fatores que contribuem para os erros nas decisões do VAR e as perspectivas de soluções futuras. Para exemplificar esses conceitos, a regra do impedimento foi escolhida, pois oferece inúmeras instâncias de ferramentas que requerem medições acuradas. Com base em procedimentos consolidados da literatura, foram apresentadas discussões sobre os atuais desafios e sugestões para compreensão e aprimoramento completos do VAR.

Self-reported versus actigraphy-assessed sleep duration in the ELSA-Brasil study: analysis of the short/long sleep duration reclassification.

PURPOSE: This study was aimed to determine the magnitude and predictors of self-reported short/long sleep duration (SDUR) reclassifications using objective measurements. METHODS: Adult participants from the ELSA-Brasil study performed self-reported SDUR, 7-day wrist actigraphy, and a portable sleep study. We explored two strategies of defining self-reported SDUR reclassification: (1) short and long SDUR defined by <6 and ≥8h, respectively; (2) reclassification using a large spectrum of SDUR categories (<5, 5-6, 7-8, 8-9, and >9 h). RESULTS: Data from 2036 participants were used in the final analysis (43% males; age: 49±8 years). Self-reported SDUR were poorly correlated (r=0.263) and presented a low agreement with actigraphy-based total sleep time. 58% of participants who self-reported short SDUR were reclassified into the reference (6-7.99 h) or long SDUR groups using actigraphy data. 88% of participants that self-reported long SDUR were reclassified into the reference and short SDUR. The variables independently associated with higher likelihood of self-reported short SDUR reclassification included insomnia (3.5-fold), female (2.5-fold), higher sleep efficiency (1.35-fold), lowest O2 saturation (1.07-fold), higher wake after sleep onset (1.08-fold), and the higher number of awakening (1.05-fold). The presence of hypertension was associated with a 3.4-fold higher chance of self-reported long SDUR reclassification. Analysis of five self-reported SDUR categories revealed that the more extreme is the SDUR, the greater the self-reported SDUR reclassification. CONCLUSION: In adults, we observed a significant rate of short/long SDUR reclassifications when comparing self-reported with objective data. These results underscore the need to reappraise subjective data use for future investigations addressing SDUR.

Characterizing Bias Due to Differential Exposure Ascertainment in Electronic Health Record Data.

Data derived from electronic health records (EHR) are heterogeneous with availability of specific measures dependent on the type and timing of patients' healthcare interactions. This creates a challenge for research using EHR-derived exposures because gold-standard exposure data, determined by a definitive assessment, may only be available for a subset of the population. Alternative approaches to exposure ascertainment in this case include restricting the analytic sample to only those patients with gold-standard exposure data available (exclusion); using gold-standard data, when available, and using a proxy exposure measure when the gold standard is unavailable (best available); or using a proxy exposure measure for everyone (common data). Exclusion may induce selection bias in outcome/exposure association estimates, while incorporating information from a proxy exposure via either the best available or common data approaches may result in information bias due to measurement error. The objective of this paper was to explore the bias and efficiency of these three analytic approaches across a broad range of scenarios motivated by a study of the association between chronic hyperglycemia and five-year mortality in an EHR-derived cohort of colon cancer survivors. We found that the best available approach tended to mitigate inefficiency and selection bias resulting from exclusion while suffering from less information bias than the common data approach. However, bias in all three approaches can be severe, particularly when both selection bias and information bias are present. When risk of either of these biases is judged to be more than moderate, EHR-based analyses may lead to erroneous conclusions.

Orchid bees (Apidae, Euglossini) from Oil Palm Plantations in Eastern Amazon Have Larger but Not Asymmetrical Wings.

Phenotypic variation in both morphology and symmetry of individuals may appear due to environmental stress caused by land-use changes. Here, we evaluated fluctuating asymmetry (FA) and wing size variations of two orchid bee species, Euglossa ignita Smith, 1874 and Eulaema meriana (Olivier, 1789), comparing 11 wing traits. We sampled the individuals from legal reserves (LR), areas of permanent protection (APP), and oil palm plantations (PALM) in Eastern Amazonia. We calculated FA as the absolute difference between the wing measurements made in the right and left wings of specimens and both species' wing size. We corrected each FA measure for possible directional asymmetry bias by subtracting the mean value of the mean FA signed difference to each FA measure. We compared FA and the size of each wing trait of each species between land-use types using one-way ANOVAs. We found no effect of FA between land-use types, but we observed individuals of both species from PALM areas having larger wings than those from LR areas. Our results demonstrate that there seems to be a pressure exerted by land-use change associated with palm oil cultivation favoring individuals with larger wings, although both species had shown substantial permeability of oil palm.

Bayesian cure fraction models with measurement error in the scale mixture of normal distribution.

Cure fraction models have been widely used to model time-to-event data when part of the individuals survives long-term after disease and are considered cured. Most cure fraction models neglect the measurement error that some covariates may experience which leads to poor estimates for the cure fraction. We introduce a Bayesian promotion time cure model that accounts for both mismeasured covariates and atypical measurement errors. This is attained by assuming a scale mixture of the normal distribution to describe the uncertainty about the measurement error. Extending previous works, we also assume that the measurement error variance is unknown and should be estimated. Three classes of prior distributions are assumed to model the uncertainty about the measurement error variance. Simulation studies are performed evaluating the proposed model in different scenarios and comparing it to the standard promotion time cure fraction model. Results show that the proposed models are competitive ones. The proposed model is fitted to analyze a dataset from a melanoma clinical trial assuming that the Breslow depth is mismeasured.

Ex post adjustment for measurement error in stunting calculations: an illustration from Egypt.

OBJECTIVE: The present study provides ranges for the magnitude of bias caused by measurement error in stunting rates, a widely used a proxy for long-term nutritional status. DESIGN: Stunting, which is determined by the number of cases that fall below -2 sd from the mean height-for-age in the population, mechanically increases with higher variance. This variance stems from both natural heterogeneity in the population and measurement error. To isolate the effect of measurement error, we model the true distributions which could give rise to the observed distributions after subtracting a simulated measurement error. SETTING: We analyse information from three rounds of the Demographic and Health Survey (DHS) in Egypt (2005, 2008 and 2014). Egypt ranks high among developing countries with low-quality anthropometric data collected in the DHS, currently the main source of anthropometry in the country. PARTICIPANTS: The study relies on re-analysis of existing DHS data, which record height, weight and age data for children under 5 years old. RESULTS: Under the most conservative assumptions about measurement error, the stunting rate falls by 4 percentage points for the most recent DHS round, while assuming higher levels of measurement error reduces the stunting rate more dramatically. CONCLUSIONS: Researchers should be aware of and adjust for data quality concerns in calculating stunting rates for cross-survey comparisons or in communicating to policy makers.

A hidden Markov model addressing measurement errors in the response and replicated covariates for continuous nondecreasing processes.

Motivated by a study tracking the progression of Parkinson's disease (PD) based on features extracted from voice recordings, an inhomogeneous hidden Markov model with continuous state-space is proposed. The approach addresses the measurement error in the response, the within-subject variability of the replicated covariates and presumed nondecreasing response. A Bayesian framework is described and an efficient Markov chain Monte Carlo method is developed. The model performance is evaluated through a simulation-based example and the analysis of a PD tracking progression dataset is presented. Although the approach was motivated by a PD tracking progression problem, it can be applied to any monotonic nondecreasing process whose continuous response variable is subject to measurement errors and where replicated covariates play a key role.

Spatiotemporal Error in Rainfall Data: Consequences for Epidemiologic Analysis of Waterborne Diseases.

The relationship between rainfall, especially extreme rainfall, and increases in waterborne infectious diseases is widely reported in the literature. Most of this research, however, has not formally considered the impact of exposure measurement error contributed by the limited spatiotemporal fidelity of precipitation data. Here, we evaluate bias in effect estimates associated with exposure misclassification due to precipitation data fidelity, using extreme rainfall as an example. We accomplished this via a simulation study, followed by analysis of extreme rainfall and incident diarrheal disease in an epidemiologic study in Ecuador. We found that the limited fidelity typical of spatiotemporal rainfall data sets biases effect estimates towards the null. Use of spatial interpolations of rain-gauge data or satellite data biased estimated health effects due to extreme rainfall (occurrence) and wet conditions (accumulated totals) downwards by 35%-45%. Similar biases were evident in the Ecuadorian case study analysis, where spatial incompatibility between exposed populations and rain gauges resulted in the association between extreme rainfall and diarrheal disease incidence being approximately halved. These findings suggest that investigators should pay greater attention to limitations in using spatially heterogeneous environmental data sets to assign exposures in epidemiologic research.

Accuracy of octa-polar bioelectrical impedance analysis for the assessment of total and appendicular body composition in children and adolescents with HIV: comparison with dual energy X-ray absorptiometry and air displacement plethysmography.

BACKGROUND: Body composition analysis has been used to investigate fat mass (FM) and bone mineral content (BMC) in children and adolescents diagnosed with HIV. Investigating the validity of bioelectrical impedance analysis (BIA) is interesting with respect to testing useful techniques for monitoring body composition in children and adolescents in clinical practice. The present study aimed to determine the validity of body composition analysis by BIA compared to dual-energy X-ray absorptiometry (DXA) and air displacement plethysmography (ADP) in children and adolescents an HIV diagnosis. METHODS: Sixty-four children and adolescents (35 females and 29 males) with a mean (SD) age of 12.22 (2.13) years and with an HIV diagnosis participated in the study. Fat-free mass (FFM), FM and body fat percentage (%BF) were obtained by BIA for comparison with DXA and ADP. Segmented FM (trunk, legs and arms), lean soft tissue mass (LSTM) (total and segmented) and BMC were obtained by BIA for comparison with DXA. RESULTS: BIA presented a clinically acceptable correlation with DXA and ADP for FFM. Values found by BIA were underestimated compared to ADP, and overestimated compared to DXA. BIA presented a clinically acceptable correlation with DXA for LSTM estimates (total and segmented parameters) in both sexes (underestimating FM and overestimating LSTM). For other components (%BF, FM and BMC), BIA had a clinically unacceptable correlation with the reference methods in both sexes. CONCLUSIONS: BIA was suitable for evaluating FFM and LSTM in children and adolescents with an HIV diagnosis. For FM, %BF and BMC, BIA was not suitable for performing an evaluation in both sexes.

Fluctuating and directional asymmetry in the long bones of captive cotton-top tamarins (Saguinus oedipus).

OBJECTIVES: Skeletal asymmetries reflect developmental stability and mechanical, functional, and physiological influences on bone growth. In humans, researchers have documented the greatest limb bone bilateral asymmetry in diaphyseal breadths, with less asymmetry in articular and maximum length dimensions. However, it remains unclear as to whether the pattern observed for humans is representative of nonhuman primates, wherein bilateral loading may minimize directional asymmetry. This study adds to the small body of asymmetry data on nonhuman primates by investigating patterns of long bone asymmetry in a skeletal sample of Saguinus oedipus (cotton-top tamarin). MATERIALS AND METHODS: Humeri, radii, ulnae, femora, and tibiae of 76 adult captive cotton-top tamarin skeletons (48 males, 28 females) were measured bilaterally. We included maximum length, midshaft diaphyseal breadths, and at least one articular measurement for each bone to assess directional (DA) and fluctuating asymmetry (FA) in each dimension. RESULTS: Most dimensions exhibit significant FA, and very few have significant DA; DA is limited to the lower limb, especially in knee dimensions. Overall, the magnitudes of asymmetry in tamarins have a consistent ranking that follows the same pattern as found in humans. DISCUSSION: This first study of DA and FA among multiple dimensions throughout the limbs of a non-hominoid primate suggests that previously-reported patterns of human bilateral asymmetry are not exclusive to humans. The results further indicate potential underlying differences in constraints on variation within limb bones. While processes shaping variation await further study, our results argue that different long bone dimensions may reflect dissimilar evolutionary processes.

Testing parallel laser image scaling for remotely measuring body dimensions on mantled howling monkeys (Alouatta palliata).

Body size is a fundamental variable for many studies in primate biology. However, obtaining body dimensions of wild primates through live capture is difficult and costly, so developing an alternative inexpensive and non-invasive method is crucial. Parallel laser image scaling for remotely measuring body size has been used with some success in marine and terrestrial animals, but only one arboreal primate. We further tested the efficacy of this method on the arboreal mantled howling monkey (Alouatta palliata) in La Pacifica, Costa Rica. We calculated interobserver error, as well as the method's repeatability when measuring the same animal on different occasions. We also compared measurements obtained physically through live capture with measurements obtained remotely using parallel laser image scaling. Our results show that the different types of error for the remote technique are minimal and comparable with the error rates observed in physical methods, with the exception of some dimensions that vary depending on the animals' posture. We conclude that parallel laser image scaling can be used to remotely obtain body dimensions if careful consideration is given to factors such as species-specific morphology and postural habits.

Accounting for unknown foster dams in the genetic evaluation of embryo transfer progeny.

Animals born by embryo transfer (ET) are usually not included in the genetic evaluation of beef cattle for preweaning growth if the recipient dam is unknown. This is primarily to avoid potential bias in the estimation of the unknown age of dam. We present a method that allows including records of calves with unknown age of dam. Assumptions are as follows: (i) foster cows belong to the same breed being evaluated, (ii) there is no correlation between the breeding value (BV) of the calf and the maternal BV of the recipient cow, and (iii) cows of all ages are used as recipients. We examine the issue of bias for the fixed level of unknown age of dam (AOD) and propose an estimator of the effect based on classical measurement error theory (MEM) and a Bayesian approach. Using stochastic simulation under random mating or selection, the MEM estimating equations were compared with BLUP in two situations as follows: (i) full information (FI); (ii) missing AOD information on some dams. Predictions of breeding value (PBV) from the FI situation had the smallest empirical average bias followed by PBV obtained without taking measurement error into account. In turn, MEM displayed the highest bias, although the differences were small. On the other hand, MEM showed the smallest MSEP, for either random mating or selection, followed by FI, whereas ignoring measurement error produced the largest MSEP. As a consequence from the smallest MSEP with a relatively small bias, empirical accuracies of PBV were larger for MEM than those for full information, which in turn showed larger accuracies than the situation ignoring measurement error. It is concluded that MEM equations are a useful alternative for analysing weaning weight data when recipient cows are unknown, as it mitigates the effects of bias in AOD by decreasing MSEP.

Estudo de calibração do Questionário de Frequência Alimentar para Adolescentes (QFAA) / Calibration study of the Food Frequency Questionnaire for Adolescents (AFFQ)

Para determinar fatores de calibração do Questionário de Frequência Alimentar para Adolescentes (QFAA), participaram do estudo 74 adolescentes de Piracicaba (SP), com idades entre 10 e 14 anos. Dados de consumo alimentar foram levantados por meio de um QFAA e dois recordatórios de 24 horas ajustados pela energia. Foram realizadas análises descritivas, análise de variância com um fator de classificação, coeficientes de correlação de Pearson e regressão linear. A média dos dois recordatórios foi utilizada como referência para calibrar os dados. Os coeficientes de calibração variaram de -0,07 (ferro) a 0,40 (vitamina C), mostrando substancial erro no método de inquérito dietético testado, mas sendo semelhantes aos observados na literatura. Devido ao fato de se apresentarem baixos, indicam a necessidade de reformulação do instrumento para alguns nutrientes, sendo desaconselhada sua aplicação para corrigir informações de ferro e retinol. A metodologia utilizada é capaz de considerar nas análises os erros de mensuração quando suas pressuposições são respeitadas, uma vez que violações desses pressupostos podem levar ao surgimento de outros erros de difícil predição.

In order to establish calibration factors of the Adolescent Food Frequency Questionnaire (AFFQ), 74 boys and girls from Piracicaba (SP, Brazil) with ages ranging from 10 to 14 took part in the study. Dietary intake (assessed by the food frequency questionnaire and 24-hour recall) was assessed and adjusted for energy intake. Descriptive statistics, variance analysis using one classification factor, Pearson's correlation coefficients and linear regression were performed. The average of two 24-hour recalls was used as a reference for calibration of data. Calibration coefficients (λ) ranged from -0.07 (iron) to 0.40 (vitamin C) revealing substantial error in the dietary method tested, albeit similar to those observed in the literature. As these coefficients were low, they indicate the need for reformulating the instrument regarding some nutrients, though application was not considered advisable for correcting information on iron and retinol. The methodology used to calibrate dietary data can consider measurement error in the assessment when its assumptions are respected, since violations of these assumptions may lead to other errors that are difficult to predict.

Confiabilidade dos dados antropométricos obtidos em crianças atendidas na Rede Básica de Saúde de Alagoas / Reliability of anthropometric data obtained in children seen at the Primary Public Healthcare Service Network in Alagoas, Brazil

Introdução: O monitoramento do crescimento infantil constitui-se em importante ferramenta para a construção de indicadores úteis ao planejamento de políticas e ações de atenção à saúde da criança. Para isso é necessário que os dados antropométricos obtidos apresentem satisfatória confiabilidade. Objetivo: Investigar a confiabilidade dos dados antropométricos produzidos nos Estabelecimentos de Assistência à Saúde (EAS) do SUS em Alagoas. Métodos: Para composição da amostra, sortearam-se 20 dentre os 102 municípios do Estado. Em seguida, dois EAS por município e, nestes, cerca de dez crianças menores de cinco anos. A amostra foi constituída de 40 EAS e 347 crianças. As medidas antropométricas (peso e estatura) foram aferidas (1) na rotina do serviço (S); (2) pelo pesquisador utilizando equipamento padrão (P) e; (3) pesquisador usando equipamentos do serviço (PS). Resultados: A aplicação do teste Kappa indicou concordância "substancial" (K = 0,69) nas classificações de peso-para-idade (PI) entre S e P e "quase perfeita" (K = 0,83) entre PS e P. Quanto à altura-para-idade (AI), a concordância entre S e P foi "discreta" (K = 0,27), passando a "moderada" (K = 0,56) entre PS e P. O Erro Técnico da Medição segundo faixas etárias ( 24 meses) indicou problemas na técnica e nos equipamentos. As medidas de peso corporal obtidas em S foram sistematicamente superestimadas (p < 0,05; teste dos sinais), o que determinou baixa sensibilidade e uma elevada taxa de falsos negativos (38,5 por cento para PI e 57,1 por cento para AI). Conclusão: A baixa confiabilidade observada para a variável altura, desaconselha sua utilização na construção de indicadores de saúde até que os EAS sejam dotados de estadiômetros adequados e pessoal qualificado a utilizá-los. Quanto à variável peso, embora possa ser utilizada, é necessário melhorar sua qualidade por meio da capacitação dos antropometristas e da aquisição e/ou manutenção dos equipamentos.

Introduction: Monitoring child growth is a very important tool not only to build useful indicators for the evaluation and planning of public policies, but also for appropriate care to child health. In order to accomplish that anthropometric data from services need to present satisfactory reliability. Objective: To investigate the reliability of weight and height variables obtained from children at public healthcare services (PHS) of Alagoas. Methods: To build the sample, 20 municipalities were drawn among the 102 of the state. Then, two PHS were drawn per municipality, and in these, about ten children under five years. The final sample consisted of 40 PHS and 347 children. Anthropometric measures (weight and height) were taken (1) during routine service (S); (2) by the researcher using standard equipment (R), and (3) by the researcher using service equipment (RS). Results: The Kappa test indicated a "substantial" level of agreement (K=0.69) in the classifications of weight-for-age (WA) between S and R and "almost perfect" (K = 0.83) in those between RS and R. Regarding height-for-age (HA), the level of agreement between S and R was "fair" (K = 0.27), to "moderate" (K = 0.56) between RS and R. A Technical Measurement Error according to age groups ( 24 months) indicated problems in the technique and equipment. Measurements of body weight obtained in PHS routine were systematically overestimated (p<0.05; sign test), leading to low sensitivity, high specificity and a high rate of false negatives (38.5 percent for WA and 57.1 percent for HA). Conclusion: The low reliability observed for the height variable cautions against its utilization to build health indicators, until the scenario can be improved. The weight variable may be used, but its quality must be improved by training anthropometrists, and through the acquisition and maintenance of equipment.

Effects of sensor, trials and knee joint variables on electrogoniometric gait recordings / Efeitos das variáveis sensor, coleta e articulação do joelho nos registros eletrogoniométricos da marcha

INTRODUCTION: Different sources of variations, such as electrogoniometer characteristics and procedures, may affect the accuracy and precision of movement measurements during gait. OBJECTIVE: To quantify the variations and compare the effects produced by different sources of variation in electrogoniometric gait recordings: the sensors, procedures (trials) and the knee joint. METHODS: Knee flexion/extension and valgus/varus movements were recorded during gait on the treadmill. The recordings were partitioned into strides and normalized in time using a routine developed in MatLab. Mean curves for the knee during gait were derived from 50 strides, and seven conditions were evaluated: one comparing pairs of sensors; two comparing pairs of different trials (including variations due to sensors); and four comparing the right and left knees (including variations due to sensors and trials). Mean standard deviations of the differences were calculated. To estimate the variations relating to the trial and the knee joint, the compound standard deviations were transformed into variances and split into their components. RESULTS: The variation introduced by pairs of sensors in the same model applied in one trial was smaller than the variation introduced by the same sensor used in two consecutive trials. Furthermore, the variation introduced by the difference between the right and left knees was greater than the variation introduced by the difference between sensors (A and B) and trials (1 and 2). CONCLUSIONS: It is, therefore, preferable to use different sensors in the same data recording (simultaneous) than use the same sensor in two different recordings (consecutive).

INTRODUÇÃO: Diferentes fontes de variação, tais como características do eletrogoniômetro e procedimentos podem afetar a acurácia e precisão das medidas do movimento durante a marcha. OBJETIVO: Quantificar a variação e comparar o efeito das diferentes fontes de variação nos registros eletrogoniométricos da marcha: os sensores, os procedimentos (coletas consecutivas) e a articulação do joelho. MÉTODOS: Movimentos de flexo-extensão e valgo-varo do joelho foram registrados durante a caminhada na esteira. Os registros foram divididos em passadas e normalizados no tempo usando uma rotina desenvolvida em MatLab. As curvas médias do joelho durante a marcha foram derivadas de 50 passadas, e sete condições foram avaliadas: uma para comparar dois sensores; duas para comparar duas diferentes coletas (incluindo a variação do sensor), e quatro para comparar os joelhos direito e esquerdo (incluindo a variação dos sensores e coletas). Os desvios-padrão médios das diferenças foram calculados. Para estimar as variações devido às coletas e à articulação do joelho, os desvios-padrão compostos foram transformados em variâncias e seus componentes isolados. RESULTADOS: A variação introduzida por dois sensores do mesmo modelo aplicados em uma coleta foi menor do que a variação introduzida pelo mesmo sensor usado em duas coletas consecutivas. Ainda, a variação introduzida pela diferença entre os joelhos direito e esquerdo foi maior do que a variação introduzida pela diferença entre os sensores (A e B) e as coletas (1 e 2). CONCLUSÕES: Assim, é preferível usar diferentes sensores na mesma coleta de dados (simultânea) do que usar o mesmo sensor em dois registros diferentes (consecutivos).