937 resultados para Recall Bias


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PURPOSE To identify the factors responsible for the poor validity of the most common aniseikonia tests, which involve size comparisons of red-green stimuli presented haploscopically. METHODS Aniseikonia was induced by afocal size lenses placed before one eye. Observers compared the sizes of semicircles presented haploscopically via color filters. The main factor under study was viewing mode (free viewing versus short presentations under central fixation). To eliminate response bias, a three-response format allowed observers to respond if the left, the right, or neither semicircle appeared larger than the other. To control decisional (criterion) bias, measurements were taken with the lens-magnified stimulus placed on the left and on the right. To control for size-color illusions, measurements were made with color filters in both arrangements before the eyes and under binocular vision (without color filters). RESULTS Free viewing resulted in a systematic underestimation of lens-induced aniseikonia that was absent with short presentations. Significant size-color illusions and decisional biases were found that would be mistaken for aniseikonia unless appropriate action is taken. CONCLUSIONS To improve their validity, aniseikonia tests should use short presentations and include control conditions to prevent contamination from decisional/response biases. If anaglyphs are used, presence of size-color illusions must be checked for. TRANSLATIONAL RELEVANCE We identified optimal conditions for administration of aniseikonia tests and appropriate action for differential diagnosis of aniseikonia in the presence of response biases or size-color illusions. Our study has clinical implications for aniseikonia management.

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Vorurteile, Macht und Diskriminierung sind die zentralen Themen des Anti-Bias-Ansatzes, der Diskriminierung auf zwischenmenschlicher, struktureller und gesellschaftlich-kultureller Ebene berücksichtigt. Die eigene Verwobenheit in Machtverhältnisse und damit verbundene Erfahrungen von Diskriminierung und Privilegierung sind dabei der Ausgangspunkt des Lernens. Vision ist eine vorurteilsbewusste, diskriminierungskritische und machtsensible Gesellschaft. Der vorliegende Beitrag stellt den Anti-Bias-Ansatz als Methode politischer Erwachsenenbildung vor. Hierfür werden die (Macht-)Mechanismen der Entstehung, Verinnerlichung und Reproduktion von Vorurteilen und Diskriminierung beleuchtet und wird die Intersektionalität (Überkreuzung) verschiedener Differenzlinien ausgemacht und aufgedeckt. Den Abschluss bildet ein Beispiel konkreter Umsetzung. (DIPF/Orig.)

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Background and Purpose: At least part of the failure in the transition from experimental to clinical studies in stroke has been attributed to the imprecision introduced by problems in the design of experimental stroke studies. Using a metaepidemiologic approach, we addressed the effect of randomization, blinding, and use of comorbid animals on the estimate of how effectively therapeutic interventions reduce infarct size. Methods: Electronic and manual searches were performed to identify meta-analyses that described interventions in experimental stroke. For each meta-analysis thus identified, a reanalysis was conducted to estimate the impact of various quality items on the estimate of efficacy, and these estimates were combined in a meta meta-analysis to obtain a summary measure of the impact of the various design characteristics. Results: Thirteen meta-analyses that described outcomes in 15 635 animals were included. Studies that included unblinded induction of ischemia reported effect sizes 13.1% (95% CI, 26.4% to 0.2%) greater than studies that included blinding, and studies that included healthy animals instead of animals with comorbidities overstated the effect size by 11.5% (95% CI, 21.2% to 1.8%). No significant effect was found for randomization, blinded outcome assessment, or high aggregate CAMARADES quality score. Conclusions: We provide empirical evidence of bias in the design of studies, with studies that included unblinded induction of ischemia or healthy animals overestimating the effectiveness of the intervention. This bias could account for the failure in the transition from bench to bedside of stroke therapies.

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Background and Purpose—As a research community, we have failed to demonstrate that drugs which show substantial efficacy in animal models of cerebral ischemia can also improve outcome in human stroke. Summary of Review—Accumulating evidence suggests this may be due, at least in part, to problems in the design, conduct and reporting of animal experiments which create a systematic bias resulting in the overstatement of neuroprotective efficacy. Conclusions—Here, we set out a series of measures to reduce bias in the design, conduct and reporting of animal experiments modeling human stroke.

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This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited.

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An investigation into the stability of metal-insulator-semiconductor (MIS) transistors based on alpha-sexithiophene is reported. In particular, the kinetics of the threshold voltage shift upon application of a gate bias has been determined. The kinetics follow stretched-hyperbola-type behavior, in agreement with the formalism developed to explain metastability in amorphous-silicon thin-film transistors. Using this model, quantification of device stability is possible. Temperature-dependent measurements show that there are two processes involved in the threshold voltage shift, one occurring at Tapproximate to220 K and the other at Tapproximate to300 K. The latter process is found to be sample dependent. This suggests a relation between device stability and processing parameters. (C) 2004 American Institute of Physics.

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PURPOSE: Nutrition is a key determinant of chronic disease in later life. A systematic review was conducted of studies examining dietary patterns and quality of life, physical function, cognitive function and mental health among older adults. METHODS: Literature searches in MEDLINE complete, Academic Search Complete, CINAHL Complete, Ageline, Global health, PsycINFO, SCOPUS and EMBASE and hand searching from 1980 up to December 2014 yielded 1236 results. Inclusion criteria included dietary pattern assessment via dietary indices or statistical approaches, a sample of community-dwelling adults aged 45 years and over at baseline and a cross-sectional or longitudinal study design. Exclusion criteria included a single 24-h recall of diet, evaluation of single foods or nutrients, clinical or institutionalised samples and intervention studies. Risk of bias was assessed using the six-item Effective Public Health Practice Project's Quality Assessment Tool for Quantitative Studies. RESULTS: There were 34 articles (11 cross-sectional and 23 longitudinal) included with 23 studies examining dietary indices and 13 studies using empirical analysis. Most studies examined mental health (n = 10) or cognitive function (n = 18), with fewer studies examining quality of life (n = 6) and physical function (n = 8). Although dietary pattern and outcome assessment methods varied, most studies reported positive associations between a healthier diet and better health outcomes. CONCLUSION: Overall, the number of studies using dietary patterns to investigate diet and successful ageing is small, and further investigation in longitudinal studies is needed, particularly for quality-of-life outcomes. This review provides support for the importance of a healthy diet for the ageing population globally.

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Preliminary research has suggested that wearable cameras may reduce under-reporting of energy intake (EI) in self-reported dietary assessment. The aim of the present study was to test the validity of a wearable camera-assisted 24 h dietary recall against the doubly labelled water (DLW) technique. Total energy expenditure (TEE) was assessed over 15 d using the DLW protocol among forty adults (n 20 males, age 35 (sd 17) years, BMI 27 (sd 4) kg/m2 and n 20 females, age 28 (sd 7) years, BMI 22 (sd 2) kg/m2). EI was assessed using three multiple-pass 24 h dietary recalls (MP24) on days 2-4, 8-10 and 13-15. On the days before each nutrition assessment, participants wore an automated wearable camera (SenseCam (SC)) in free-living conditions. The wearable camera images were viewed by the participants following the completion of the dietary recall, and their changes in self-reported intakes were recorded (MP24+SC). TEE and EI assessed by the MP24 and MP24+SC methods were compared. Among men, the MP24 and MP24+SC measures underestimated TEE by 17 and 9%, respectively (P< 0.001 and P= 0.02). Among women, these measures underestimated TEE by 13 and 7%, respectively (P< 0.001 and P= 0.004). The assistance of the wearable camera (MP24+SC) reduced the magnitude of under-reporting by 8% for men and 6% for women compared with the MP24 alone (P< 0.001 and P< 0.001). The increase in EI was predominantly from the addition of 265 unreported foods (often snacks) as revealed by the participants during the image review. Wearable cameras enhance the accuracy of self-report by providing passive and objective information regarding dietary intake. High-definition image sensors and increased imaging frequency may improve the accuracy further.

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The aim of the study was to validate the self-report Multimedia Activity Recall for Children and Adolescents (MARCA) against accelerometry for the assessment of physical activity in New Zealand children. Participants (n = 716, 10-18 years) recalled 3-4 days of activity using the MARCA and underwent a partially overlapping 7-day accelerometry protocol during a national survey. Spearman correlation coefficients (ρ) assessed the association between accelerometer-derived counts per minute and MARCA-derived physical activity level and time in locomotion. Both data sources estimated time spent in light and moderate-vigorous physical activity. Association and agreement between methods for light physical activity and moderate-vigorous physical activity was assessed using correlations and Bland-Altman plots respectively, and paired t-tests conducted. Accelerometer-derived activity counts were moderately correlated with both MARCA-derived physical activity level and locomotion (ρ = 0.38, P < 0.0001). The correlation between methods was -0.14 for light physical activity and 0.28 for moderate-vigorous physical activity (P < 0.0001). The MARCA overestimated moderate-vigorous physical activity compared with accelerometry (120 min, P < 0.0001), which increased as moderate-vigorous physical activity time increased. Some sex and ethnicity (Māori [indigenous] versus non-Māori) differences were observed. Overall, the MARCA indicated moderate validity for assessment of physical activity level, locomotion and moderate-vigorous physical activity and poor validity for assessment of light physical activity. This was comparable to other self-report tools. The MARCA has utility for future large-scale research.

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BACKGROUND: The Multimedia Activity Recall for Children and Adults (MARCA) is a computerized recall instrument that records use of time during 24 hr the previous day and has been developed to address limitations of current self-report physical activity measures for those in advanced age. METHODS: Test-retest reliability and convergent validity of the adult MARCA were assessed in a sample of 45 advanced-age adults (age 84.9 SD ± 1.62 yr) as a subsample of the Life and Living in Advanced-Age Cohort Study New Zealand (LiLACS NZ). Test-retest methods required participants to recall the previous day's activity using the MARCA twice within the same day. Convergent validity was assessed against accelerometry. RESULTS: Test-retest reliability was high, with ICCs greater than .99 for moderate to vigorous physical activity (MVPA) and physical activity level (PAL). Compared with accelerometry, the MARCA demonstrated validity comparable to other self-report instruments with Spearman's coefficients of .34 and .59 for time spent in nonsedentary physical activity and PAL. CONCLUSION: The MARCA is a valid and reliable self-report tool for physical activity behaviors in advanced-age adults.

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OBJECTIVE: Low levels of daily energy expenditure (insufficient physical activity and increased sedentary time) have been associated with adverse health outcomes in young people. The Multimedia Activity Recall for Children and Adolescents (MARCA) is a computerized, self-report, use-of-time tool that can assess daily energy expenditure. The study aim was to validate the MARCA for the estimation of energy expenditure in young people, using the criterion standard doubly labeled water. MATERIALS/METHODS: Over a 15 day assessment period, 32 participants (10-18 years) completed the MARCA and underwent a doubly labeled water protocol. Indirect calorimetry was used to assess resting metabolic rate. Total daily energy expenditure (TEE) and activity-related energy expenditure (AEE) were estimated from both the MARCA and doubly labeled water. Association and agreement between methods for TEE and AEE were assessed using Spearman correlations and Bland-Altman plots, respectively. RESULTS: Compared to doubly labeled water, the MARCA over-estimated TEE by an average of 50 kcal/day (limits of agreement -1 589 to 1 490 kcal/day) and under-estimated AEE 105 kcal/day (limits of agreement -1 404 to 1 614 kcal/day). The MARCA showed strong correlation with doubly labeled water for TEE (rho=0.70, p<0.0001) and moderate correlation for AEE (rho=0.56, p=0.0009). CONCLUSIONS: Overall, the MARCA indicated moderate validity for the assessment of daily TEE and AEE. The wide limits of agreement indicate the MARCA has greater utility for group-level rather than individual-level estimates.

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BACKGROUND: To aid in the differentiation of individuals with major depressive disorder (MDD) from healthy controls, numerous peripheral biomarkers have been proposed. To date, no comprehensive evaluation of the existence of bias favoring the publication of significant results or inflating effect sizes has been conducted. METHODS: Here, we performed a comprehensive review of meta-analyses of peripheral nongenetic biomarkers that could discriminate individuals with MDD from nondepressed controls. PubMed/MEDLINE, EMBASE, and PsycINFO databases were searched through April 10, 2015. RESULTS: From 15 references, we obtained 31 eligible meta-analyses evaluating biomarkers in MDD (21,201 cases and 78,363 controls). Twenty meta-analyses reported statistically significant effect size estimates. Heterogeneity was high (I2 ≥ 50%) in 29 meta-analyses. We plausibly assumed that the true effect size for a meta-analysis would equal the one of its largest study. A significant summary effect size estimate was observed for 20 biomarkers. We observed an excess of statistically significant studies in 21 meta-analyses. The summary effect size of the meta-analysis was higher than the effect of its largest study in 25 meta-analyses, while 11 meta-analyses had evidence of small-study effects. CONCLUSIONS: Our findings suggest that there is an excess of studies with statistically significant results in the literature of peripheral biomarkers for MDD. The selective publication of 'positive studies' and the selective reporting of outcomes are possible mechanisms. Effect size estimates of meta-analyses may be inflated in this literature.

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OBJECTIVE: To investigate reporting of alcohol consumption, we manipulated the contexts of questions in ways designed to induce social desirability bias. METHOD: We undertook a two-arm, parallel-group, individually randomized trial at an Australian public university. Students were recruited by email to a web-based "Research Project on Student Health Behavior." Respondents answered nine questions about their physical activity, diet, and smoking. They were unknowingly randomized to a group presented with either (A) three questions about their alcohol consumption or (B) seven questions about their alcohol dependence and problems (under a prominent header labeled "Alcohol Use Disorders Identification Test"), followed by the same three alcohol consumption questions from (A). RESULTS: A total of 3,594 students (mean age = 27, SD = 10) responded and were randomized: 1,778 to Group A and 1,816 to Group B. Outcome measures were the number of days they drank alcohol, the typical number of drinks they consumed per drinking day, and the number of days they consumed six or more drinks. The primary analysis included participants with any alcohol consumption in the preceding 4 weeks (1,304 in Group A; 1,340 in Group B) using between-group, two-tailed t tests. RESULTS: In Groups A and B, respectively, means (and SDs) of the number of days drinking were 5.89 (5.92) versus 6.06 (6.12), p = .49; typical number of drinks per drinking day: 4.02 (3.87) versus 3.82 (3.76), p = .17; and number of days consuming six or more drinks: 1.69 (2.94) versus 1.67 (3.25), p = .56. CONCLUSIONS: We could not reject the null hypothesis because earlier questions about alcohol dependence and problems showed no sign of biasing the respondents' subsequent reports of alcohol consumption. These data support the validity of university students' reporting of alcohol consumption in web-based studies.

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This chapter aims to see if English textbooks written for high school students in Iran are in favor of a particular gender. To this end, four English textbooks currently taught in the Iranian high schools were analysed on the basis of Systemic Functional Linguistics. Five categories were identified and two types of analyses were conducted- content analysis and linguistic. The result of the content analysis demonstrated a significant difference between the frequencies in male-female distribution. The linguistic analysis revealed that there are more males in theme and rheme positions as well as participants role, expecting for the Sensor role, The differences could be attributed to the writers' attitudes, culture, and patriarchal structure of the Iranian families.

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BACKGROUND: To date no comprehensive evaluation has appraised the likelihood of bias or the strength of the evidence of peripheral biomarkers for bipolar disorder (BD). Here we performed an umbrella review of meta-analyses of peripheral non-genetic biomarkers for BD. METHOD: The Pubmed/Medline, EMBASE and PsycInfo electronic databases were searched up to May 2015. Two independent authors conducted searches, examined references for eligibility, and extracted data. Meta-analyses in any language examining peripheral non-genetic biomarkers in participants with BD (across different mood states) compared to unaffected controls were included. RESULTS: Six references, which examined 13 biomarkers across 20 meta-analyses (5474 BD cases and 4823 healthy controls) met inclusion criteria. Evidence for excess of significance bias (i.e. bias favoring publication of 'positive' nominally significant results) was observed in 11 meta-analyses. Heterogeneity was high for (I 2 ⩾ 50%) 16 meta-analyses. Only two biomarkers met criteria for suggestive evidence namely the soluble IL-2 receptor and morning cortisol. The median power of included studies, using the effect size of the largest dataset as the plausible true effect size of each meta-analysis, was 15.3%. CONCLUSIONS: Our findings suggest that there is an excess of statistically significant results in the literature of peripheral biomarkers for BD. Selective publication of 'positive' results and selective reporting of outcomes are possible mechanisms.