Measurement Error In Assessment Research Articles

Patient-Determined Important Change for the Neck Disability Index With Application of Credibility Analysis: An Exploratory Study

ObjectiveThe purposes of this study were to preliminarily report patient-identified change for the neck disability index (NDI) as either important or not important with time between follow-up of approximately 7 to 10 days and assess the credibility of the preliminary results with the use of a recently established credibility instrument. MethodsThis study was a secondary analysis from a primary randomized clinical trial assessing short-term physical therapist care for individuals with mechanical neck pain. Neck disability index scores and participant-reported importance of global rating of change scores from 42 participants were analyzed from a randomized clinical trial assessing short-term responses to thoracic manipulation and dry needling for neck pain. Patient-important change was computed using receiver operating characteristic curves, and statistical error of the measurement was calculated using (SD × [1 − r]1/2) × 1.96 to assess measurement error at the 95% CI. ResultsThirty-six participants rated global rating of change as important, and 6 rated it as not important. Patient-important change was calculated at 3.5 NDI points on a 0 to 50 NDI scoring scale. This value exceeded the statistical error, which was calculated at 2.16 NDI points. The credibility analysis revealed that 4 of 5 criteria showed strong credibility for the patient-important change estimate. ConclusionUsing patient-determined importance to dichotomize improvement may yield a lower threshold than current researcher-defined methods. Clinically, these results may be more responsive to patient-centric change than using previously reported minimal clinically important difference data.

Exploring Effects of Race and Differential Item Functioning on PrEP Stigma Experiences: Implications for Latent Stigma Measurement in Racially and Sexually Diverse Populations.

PrEP stigma measurement remains a challenge to the validity of studies and interventions addressing HIV prevention. It may lead to inaccurate assessment of the relationship between PrEP stigma and health outcomes such as PrEP persistence and care retention in groups experiencing HIV-related inequities. The present research explored the psychometric properties of a novel IV pre-exposure prophylaxis (PrEP) stigma scalein a cohort of racially diverse men who have sex with men (MSM). Using item response theory, analyses explored presence of differential item functioning (DIF)among Black and White respondents. Participants completed baseline surveys measuring psychosocial factors, sociodemographic factors, and PrEP stigma items. The primary analysis used a machine learning approach to assess (a) the presence of DIF; and (b) compare latent stigma between Black and White respondents, after correcting for any DIF. The model identified four out of 13 scale items as having a high probability of DIFfor Black respondents, which is relatively good given that the original PrEP stigma scale was neitherdesigned nor tested for validation comparing Black and White respondents. The DIF-adjusted latent PrEP stigma measure reveals statistically and substantially significantly higher levels of stigma for Black compared to White respondents (Diff.: 1.05 +/- 0.19). While most items performed well, findings demonstrate the importance of assessing measurement error in populations where stigma is rampant and being studied or intervened upon (and in this case, where multilevel and intersectional stigma may be present).

TENDINopathy Severity assessment–Achilles (TENDINS-A): evaluation of reliability and validity in accordance with COSMIN recommendations

ObjectiveTo evaluate the construct validity (structural validity and hypothesis testing), reliability (test–retest reliability, measurement error and internal consistency) and minimal important change (MIC) of the 13-item TENDINopathy Severity assessment–Achilles (TENDINS-A).MethodsParticipants...

Decoding the misperception: Exploring measurement error in self-rated assessments of diet quality

How much should we trust self-rated diet quality? Measures based on self-perception are often used in diet evaluation, but they can sometimes be subject to diverse biases. Using a unique setting provided by the nationally representative FoodAPS data where questions about diet quality are asked twice with intermediate reminders in between, we first show that the structure of survey questions can help identify inconsistency in the respondents’ self-rated diet quality. Findings reveal that respondents tend to deliver responses that align with their earlier responses. We then validate the respondents’ self-rated diet quality against their household’s healthy eating index, an objective measure of diet quality based on actual food acquisitions. We find no statistically significant association between self-rated diet quality and healthy eating index for respondents who display inconsistency in self-assessing their diet quality. Conversely, that relationship is significant for respondents with no such inconsistency. Our findings suggest an effective question design measuring diet quality, that can be generalized to the design of health survey questions.

Reliability, validity, and responsiveness of the simplified Chinese version of the knee injury and Osteoarthritis Outcome Score in patients after total knee arthroplasty

ObjectivesThe Knee Injury and Osteoarthritis Outcome Score (KOOS) has been utilized to evaluate short- and long-term outcomes in individuals following knee injuries, such as those with anterior cruciate ligament reconstruction and knee osteoarthritis, but has not yet been applied to individuals undergoing total knee arthroplasty (TKA) in China. The aim of this study was to assess the psychometric properties of the Simplified Chinese version of the KOOS in Chinese individuals undergoing TKA. MethodsThis study distributed 170 questionnaires, and assessed the KOOS of the participants, along with requiring them to complete the Short Form 36 (SF-36) survey. There were 35 participants completed a test-retest reliability survey with a 24-h interval, 129 participants completed a pre - surgery survey, and 119 individuals completed a post - surgery survey 6 weeks after the surgery. The following tests were conducted: Cronbach's alpha (α) to assess internal consistency, intraclass correlation coefficient (ICC) to evaluate test-retest reliability, Spearman's correlation coefficient (ρ) to examine construct validity, effect size (ES) to detect measure responsiveness, minimal detectable change (MDC) to assess measurement errors. Floor and ceiling effects (<15%) were also asses evaluated. ResultsThe simplified Chinese version of the KOOS showed good test-retest reliability in participants after TKA, with an ICC of 0.82–0.97 (95% CI). The internal consistency of the five subscales of the KOOS was good (Cronbach's α = 0.70–0.96). No floor or ceiling effects were found. Regarding construct validity, a strong positive correlation was found between each of the three KOOS subscales (activities of daily living, knee-related Quality of Life, and sport and recreation subscales) and the general health and bodily pain subscales of the SF-36 (0.53 < ρ < 0.61). The subscales of the simplified Chinese version of the KOOS showed responsiveness (ES: 0.68 to 0.86) before and after 6 weeks of physical treatment. The MDC ranged from 10.28 to 23.24. ConclusionsThe Chinese version of the KOOS showed good psychometric properties and was found to be valid, reliable, and simple as an assessment tool for symptoms, pain, activity of daily living, sports and recreational activity and quality of life for the Chinese population suffering from TKA.

Enhancing discharge estimation from SWOT satellite data in a tropical tidal river environment

The Surface Water and Ocean Topography (SWOT) mission aims to provide essential data on river width, height and slope in order to estimate worldwide river discharge accurately. This mission offers a powerful tool for monitoring river discharge in dynamic coastal areas, like the Saigon-Dongnai estuary in Southern Vietnam. However, estimating discharge of tidally-influenced rivers using SWOT measurements can be challenging when hydraulic variables have the same order of magnitude as SWOT measurement errors. In this paper we present a methodology to enhance discharge estimation accuracy from SWOT measurements based on simulated SWOT products at the 200 meter node resolution and varying river reach size. We assess measurement error variability and its impact on discharge estimation by employing a Monte Carlo analysis. Our approach significantly improved discharge estimation in the Saigon tidal river, reducing RMSE from 1400 m3/s to 180 m3/s and increasing R² from 0.31 to 0.95. Notably, the percentage of Monte Carlo particles meeting the 30% rRMSE threshold rose from 0% to 79%. This study underscores the feasibility of obtaining reliable discharge estimates from SWOT data in complex coastal areas where hydraulic variables are of the same order of magnitude as SWOT errors. Additionally, the proposed methodology to improve discharge estimation from SWOT measurements is widely adaptable as it can be applied to similar regions and can be combined with any discharge estimation method.

Heat Exposure among Adult Women in Rural Tamil Nadu, India.

Exposure to heat is associated with a substantial burden of disease and is an emerging issue in the context of climate change. Heat is of particular concern in India, which is one of the world's hottest countries and also most populous, where relatively little is known about personal heat exposure, particularly in rural areas. Here, we leverage data collected as part of a randomized controlled trial to describe personal temperature exposures of adult women (40-79 years of age) in rural Tamil Nadu. We also characterize measurement error in heat exposure assessment by comparing personal exposure measurements to the nearest ambient monitoring stations and to commonly used modeled temperature data products. We find that temperatures differ across individuals in the same area on the same day, sometimes by more than 5 °C within the same hour, and that some individuals experience sharp increases in heat exposure in the early morning or evening, potentially a result of cooking with solid fuels. We find somewhat stronger correlations between the personal exposure measurements and the modeled products than with ambient monitors. We did not find evidence of systematic biases, which indicates that adjusting for discrepancies between different exposure measurement methods is not straightforward.

Analysis of the concurrent validity and reliability of five common clinical goniometric devices

Measurement errors play an important role in the development of goniometric equipment, devices used to measure range of motion. Reasonable validity and reliability are critical for both the device and examiner before and after to testing in human subjects. The objective is to evaluate the concurrent validity and reliability of five different clinical goniometric devices for the purpose of establishing an acceptable measurement error margin for a novel device. We explored the validity and inter- and intrarater reliability scores of five goniometric devices namely (i) the universal goniometer (UG), a two-armed hand-held goniometer, (ii) the inclinometer (IC), featuring a single base, fluid level, and gravity-weighted inclinometer, (iii) the digital inclinometer (DI), functioning as both a DI and dynamometer, (iv) the smartphone application (SA), employing gyroscope-based technology within a smartphone platform application and (v) the modified inclinometer (MI), a gravity pendulum-based inclinometer equipped with a specialized fixing apparatus. Measurements were obtained at 12 standard angles and 8 human shoulder flexion angles ranging from 0° to 180°. Over two testing sessions, 120 standardized angle measurements and 160 shoulder angle measurements from 20 shoulders were repetitively taken by three examiners for each device. The intraclass correlation coefficient (ICC), standard error of measurement (SEM), and minimal detectable change (MDC) were calculated to assess reliability and validity. Concurrent validity was also evaluated through the execution of the 95% limit of agreement (95% LOA) and Bland–Altman plots, with comparisons made to the UG. The concurrent validity for all device pairs was excellent in both study phases (ICC > 0.99, 95% LOA − 4.11° to 4.04° for standard angles, and − 10.98° to 11.36° for human joint angles). Inter- and intrarater reliability scores for standard angles were excellent across all devices (ICC > 0.98, SEM 0.59°–1.75°, MDC 1°–4°), with DI showing superior reliability. For human joint angles, device reliability ranged from moderate to excellent (ICC 0.697–0.975, SEM 1.93°–4.64°, MDC 5°–11° for inter-rater reliability; ICC 0.660–0.996, SEM 0.77°–4.06°, MDC 2°–9° for intra-rater reliability), with SA demonstrating superior reliability. Wider angle measurement however resulted in reduced device reliability. In conclusion, our study demonstrates that it is essential to assess measurement errors independently for standard and human joint angles. The DI is the preferred reference for standard angle testing, while the SA is recommended for human joint angle testing. Separate evaluations across the complete 0°–180° range offer valuable insights.

A Mixture Model Approach to Assessing Measurement Error in Surveys Using Reinterviews

Abstract Researchers are often unsure about the quality of the data collected by third-party actors, such as survey firms. This may be because of the inability to measure data quality effectively at scale and the difficulty with communicating which observations may be the source of measurement error. Researchers rely on survey firms to provide them with estimates of data quality and to identify observations that are problematic, potentially because they have been falsified or poorly collected. To address these issues, I propose the QualMix model, a mixture modeling approach to deriving estimates of survey data quality in situations in which two sets of responses exist for all or certain subsets of respondents. I apply this model to the context of survey reinterviews, a common form of data quality assessment used to detect falsification and data collection problems during enumeration. Through simulation based on real-world data, I demonstrate that the model successfully identifies incorrect observations and recovers latent enumerator and survey data quality. I further demonstrate the model’s utility by applying it to reinterview data from a large survey fielded in Malawi, using it to identify significant variation in data quality across observations generated by different enumerators.

Validation of Total Water Intake from the Automated Self-Administered 24-h Recall, 4-d Food Records, and a Food Frequency Questionnaire Using Doubly Labeled Water

Although prior evidence indicates that water intake is important for health, the ability to accurately measure community-dwelling intake is limited. Only a few studies have evaluated self-reported water intake against an objective recovery biomarker. The aim was to compare preformed water intakes (all sources including food) by multiple Automated Self-Administered 24-h recalls (ASA24s), food frequency questionnaires (FFQs), and 4-d food records (4DFRs) against a recovery biomarker, doubly labeled water (DLW), to assess measurement error. Over 1 y, 1082 women and men (50%), aged 50 to 74 y, were asked to complete 6 ASA24s, 2 FFQs, 2 unweighted 4DFRs, and an administration of DLW (n = 686). Geometric means of water intake by self-report tools were compared with DLW. Attenuation factors and correlation coefficients between self-reported and the recovery biomarker (DLW) were estimated. Mean water intakes by DLW were 2777 mL/d (interquartile range, 2350 to 3331) in women and 3243 mL/d (interquartile range, 2720 to 3838) in men. Compared with DLW, water intake was underestimated by 18% to 31% on ASA24s and 43% to 44% on 4DFRs. Estimated geometric means from FFQs differed from DLW by -1% to +13%. For a single ASA24, FFQ, and 4DFR, attenuation factors were 0.28, 0.27, and 0.32 and correlation coefficients were 0.46, 0.48, and 0.49, respectively. Repeated use of 6 ASA24s, 2 FFQs, and 2 4DFRs improved attenuation factors to 0.43, 0.32, and 0.39 and correlation coefficients to 0.58, 0.53, and 0.54, respectively. FFQs may better estimate population means for usual water intake compared with ASA24 and 4DFR. Similar attenuation factors and correlation coefficients across all self-report tools indicate that researchers have 3 feasible options if the goal is understanding intake-disease relationships. The findings are useful for planning future nutrition studies that set policy priorities for populations and to understand the health impact of water. This trial was registered at clinicaltrials.gov as NCT03268577.

Major Gaps in Understanding Dietary Supplement Use in Health and Disease.

Precise dietary assessment is critical for accurate exposure classification in nutritional research, typically aimed at understanding how diet relates to health. Dietary supplement (DS) use is widespread and represents a considerable source of nutrients. However, few studies have compared the best methods to measure DSs. Our literature review on the relative validity and reproducibility of DS instruments in the United States [e.g., product inventories, questionnaires, and 24-h dietary recalls (24HR)] identified five studies that examined validity (n = 5) and/or reproducibility (n = 4). No gold standard reference method exists for validating DS use; thus, each study's investigators chose the reference instrument used to measure validity. Self-administered questionnaires agreed well with 24HR and inventory methods when comparing the prevalence of commonly used DSs. The inventory method captured nutrient amounts more accurately than the other methods. Reproducibility (over 3 months to 2.4 years) of prevalence of use estimates on the questionnaires was acceptable for common DSs. Given the limited body of research on measurement error in DS assessment, only tentative conclusions on these DS instruments can be drawn at present. Further research is critical to advancing knowledge in DS assessment for research and monitoring purposes.

Assessing Measurement Error in Hypothetical Questions

The hazard of asking survey participants hypothetical questions is that most often, responses are only an inferential vehicle for understanding preference and may not reflect the truth. Often it is necessary to make a reasoned assumption about the alignment of an individual's attitudes and behaviors. In this paper, we discuss results from a Survey of Doctorate Recipients (SDR) pilot study experiment that found significant response bias to hypothetical questions even when the hypothetical context was unambiguous and included salient properties which were familiar to respondents from prior experience. The experiment asked Treatment group participants to report their reaction to slight alterations in the SDR instrument; meanwhile, those in the Control group were asked hypothetically how they *would react* to the protocol if they had experienced the same changes. We identify the presence of response bias across 10 respondent experience questions using both categorical and quantitative methods. Our results show that the Control group consistently exhibited less preference for the hypothetical protocol than the Treatment group. We believe these differences are representative of the measurement error resulting from the poor correspondence between the Control group's hypothetical attitudes and the Treatment group's reported experience. This work shows that hypothetical bias is a concern in opinion research even when hypothetical conditions may be clearly understood by respondents and similar to their previous experiences.

A Comparison of Person-Fit Indices to Detect Social Desirability Bias.

Social desirability bias (SDB) has been a major concern in educational and psychological assessments when measuring latent variables because it has the potential to introduce measurement error and bias in assessments. Person-fit indices can detect bias in the form of misfitted response vectors. The objective of this study was to compare the performance of 14 person-fit indices to identify SDB in simulated responses. The area under the curve (AUC) of receiver operating characteristic (ROC) curve analysis was computed to evaluate the predictive power of these statistics. The findings showed that the agreement statistic outperformed all other person-fit indices, while the disagreement statistic , dependability statistic , and the number of Guttman errors also demonstrated high AUCs to detect SDB. Recommendations for practitioners to use these fit indices are provided.

Measurement error in echocardiographic assessment of aortic stenosis: an epidemiological consideration of research methodology and clinical practice

Abstract Background/Introduction Current international guidelines on treatment of valvular heart disease contain recommendations for aortic valve replacement based exclusively on abnormal echocardiographic parameters in asymptomatic patients with aortic stenosis (AS). To prevent misclassification and subsequent mistreatment of patients, these recommendations require accurate and unbiased measurements of hemodynamic parameters. Purpose To illustrate consideration and impact of measurement error in echocardiographic assessment of aortic stenosis in both the research and clinical setting. Methods First, a systematic review was performed to investigate the recognition of and correction for measurement error in clinical studies on the prognostic value of peak aortic jet velocity (Vmax), mean pressure gradient (MPG), and effective orifice area (EOA). Second, all potential erroneous sources in the calculation of those primary parameters were listed stratified to random or systematic measurement error, and subsequently their magnitude was quantified. Third, the impact of various types of measurement error on current thresholds for intervention was graphically illustrated in different clinical scenarios. Results The presence of measurement error was acknowledged in 44% of the 36 included studies, while none utilized methods to correct for it. Interobserver variability ranged between 0.9–8.3% for Vmax and MPG but was substantially higher for EOA (range 7.7–12.7%) implying lower reliability (Figure 1). Furthermore, the invalid assumption of a circular left ventricular outflow tract area resulted in a median underestimation in EOA of 22.5% compared to 3D-transesophageal echocardiography (3D-TEE), computed tomography (CT), and cardiovascular magnetic resonance (CMR) planimetry. Figure 2 illustrates the impact of this discrepancy on the classification of AS using one-sided t-tests to determine the areas under the curve; the proportion of patients with non-severe AS in a hypothetical cohort (based on values from the PARTNER 3 trial [1[) increased by 42%. Conclusion(s) Measurement error is underrecognized in studies of echocardiographic assessment of aortic stenosis. This review demonstrates that random and systematic measurement errors affect echocardiographic assessment, leading to potential misdiagnosis and subsequent mistreatment. Clinicians and scientists should be aware of the implications of measurement errors to enhance rightful clinical decision-making and assure research validity. Funding Acknowledgement Type of funding sources: None.

Epidemiology of Thyroid Cancer.

Epidemiology of Thyroid Cancer.

Quality of life instruments in atrial fibrillation: a systematic review of measurement properties

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Medtronic Background Atrial fibrillation (AF) is the most common arrhythmia worldwide. A key objective of AF management is symptom reduction, as quality of life (QoL) is lower for patients with AF. QoL outcomes are important for evaluating AF therapies primarily indicated for symptom control, including catheter ablation. The aim of this systematic review is to identify the most frequently used QoL instruments across AF ablation studies and to critically appraise their measurement properties. Methods and results A literature mapping exercise was completed to identify the most frequently used QoL instruments in AF ablation studies published in the past five years. A systematic review was then undertaken to critically appraise the measurement properties of the identified QoL instruments: EQ-5D, SF-36, AFEQT (AF Effect on QualiTy-of-Life), AFSS (AF Severity Scale), MLHF-Q (Minnesota Living with Heart Failure Questionnaire), AFQLQ (AF Quality of Life Questionnaire), ASTA (Arrhythmia Specific questionnaire in Tachycardia and Arrhythmia), and SCL (Arrhythmia Symptom Checklist, Frequency and Severity). The systematic review was designed using the COSMIN guidelines for systematic reviews of patient-reported outcome measurements, and was focused on the measurement properties of validity, reliability, and responsiveness. A systematic search of the literature was conducted in Ovid MEDLINE, Ovid Embase, Ovid PsycINFO, EBSCO CINAHL, and Cochrane CENTRAL. A meta-analysis was not feasible due to significant heterogeneity between studies and measurement properties, therefore results were synthesized qualitatively. 17 studies and 8 instruments were identified that met the eligibility criteria. ASTA and AFEQT had the best ratings across measurement properties with both instruments having good ratings for prom development and internal consistency. However, none of the studies assessed measurement error and cross-cultural validity. Measurement properties were inconsistent across different studies appraising the same instrument. Conclusions AFEQT and ASTA had the strongest measurement properties but not all measurement properties have been assessed. Considering the large number of indeterminate and insufficient ratings, future research should focus on cross-cultural validation, measurement error, responsiveness, and interpretability.

A conversational-based dietary assessment tool for cardiovascular patients

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiovascular diseases (CVDs) are currently the leading cause of death worldwide. Accumulated evidence indicates that a healthy diet contributes significantly to health promotion and an increase of quality of life for those living with CVDs. While dietary intake management is an integral part of cardiac rehabilitation (CR), tracking dietary intake is burdensome, resulting in measurement errors caused by low adherence, incomplete data, or erroneous information. Objective Dietary assessment tools, such as 24-hour Dietary Recall (24HR) or Food Frequency Questionnaire (FFQ), are developed to help patients to reflect on their dietary intake but are often burdensome. To lower tracking burden and reduce measurement errors, conversational agents, i.e., chatbots, promise to improve self-reported dietary assessment by increasing flexibility and reliability. Therefore, this qualitative study aimed to evaluate the utility of a conversational-based dietary assessment tool among experts. Methods We developed a nutrition chatbot to track dietary intake and provide feedback to support people in understanding their dietary choices. The chatbot provides web-based dietary assessment either in 3h recalls, following standard procedure, or tailored recall periods. Participants are reminded to register their food intake through push notifications. Users can start reporting by choosing food categories as derived from the Dutch Food Composition Database (FCDB). When selecting a food category, follow-up questions are asked regarding the food items and the corresponding portion size in household measures, i.e., spoons, cups, glasses, handfuls, or weight in grams. We applied Fuzzy Terminology Recognition, which enabled users to enter the food item, reducing overall selection time. Meanwhile, the traffic light system, based on the Dutch Nutrition Guidelines, was implemented to support self-reflection. We conducted a study with 9 experts specialized in the field of CR or dietary behavior management, who were asked to use the chatbot to self-report their dietary intake for one week. Results The results show that the chatbot is easy to interact with and experts praised the simplicity and flexibility of using the chatbot. According to the experts, the chatbot could bridge the cognitive gap between how patients perceive their dietary habits and their actual habitual intake. They pointed out that self-reporting and feedback of the dietary choices could potentially raise awareness for dietary intake. Further, the experts mentioned that to maintain simplicity, the kind of information presented should be carefully considered. Conclusion The results from the expert reviews are promising and suggest the benefits of applying the chatbot for self-reporting dietary intake. Next, the chatbot will be included in a clinical trial with cardiovascular patients to further evaluate adherence, user experience, and the effects on measurement errors in dietary intake assessment.

Estimating measurement error in child language assessments administered by daycare educators in large scale intervention studies.

Measurement error is a ubiquitous element of social science studies. In large-scale effectiveness intervention studies on child language, administration of the assessment of language and preliteracy outcomes by speech and language pathologists is costly in money and human resources. Alternatively, daycare educators can administer the assessment, which preserves considerable resources but may increase the measurement error. Using data from two nationwide child language intervention studies in Denmark, this article evaluates daycare educators’ measurement error when administering a test of language and preliteracy skills of 3 to 5 year old children that in part is used in a national screening program. Since children were randomly assigned to educators, hierarchical linear models can estimate the amount of additional measurement error caused by educators’ language assessments. The result shows that the amount of additional measurement error varied between different language subscales, ranging from 4% to 19%, which can be compensated for by increasing the sample size by the latter percentage. The benefits and risks of having daycare educators administer language assessments are discussed.

Test-Retest Reliability of the Timed Up and Go Test in Subjects with Parkinson's Disease: Implications for Longitudinal Assessments.

Despite the frequent use of the Timed Up and Go (TUG) test in clinical trials, evaluation of longitudinal test-retest reliability is generally lacking and still inconclusive for patients with Parkinson's disease (PD). We aimed to further investigate long-term reliability and sensitivity of the TUG test among this population. Furthermore, we explored alternative assessment strategies of the test aimed at elucidating whether the inclusion or combination of timed trials may have potential implications on outcome measure. Relative and absolute reliability of the TUG performance were obtained in forty-three subjects with PD over three timed trials in two different testing sessions separated by a two-months period. Our results reported excellent intra-session and moderate inter-session reliability coefficients. The use of different assessment strategies of the TUG was found to have an important impact on outcome measure, highlighting the averaging of several timed trials in each testing session as a recommended alternative to minimize measurement error and increase reliability in longitudinal assessments. Nevertheless, beyond acceptable reliability, poor trial-to-trial stability of the measure appears to exist, since the ranges of expected variability upon retesting were wide and the incidence of spurious statistical effects was not negligible, especially in longitudinal repeated testing. Limitations may exist in the interpretation of the TUG outputs as part of longitudinal assessments aimed at evaluating treatment effectiveness in PD population. Researchers and practitioners should be aware of these concerns to prevent possible misrepresentations of functional ability in patients for a particular intervention.

Male Genital Self-Image Scale (MGSIS): Cutoff Point, Cultural Adaptation and Validation of Measurement Properties in Brazilian Men

BackgroundConcerns about genital self-image (GSI) can influence sexual function and quality of life, and instruments that assess male GSI, such as the Male Genital Self-Image Scale (MGSIS), need to be adapted and validated in different cultures. AimsTo culturally adapt and validate the measurement properties of MGSIS in Brazilian men, according to the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guideline, and to create a cutoff point for satisfaction with male GSI. MethodsWe assessed the validity of content through a committee of experts and cognitive interviews. The internal consistency and test-retest reliability were assessed using Cronbach's α and Intraclass Correlation Coefficient (ICC). We also calculate measurement errors using the Bland and Altman graph. The structural validity was investigated through exploratory and confirmatory factor analysis. The hypothesis test for construct validity was assessed using Spearman correlation from MGSIS with the International Index of Erectile Function (IIEF), Body Appreciation Scale (BAS-2) and Rosenberg Self-Esteem Scale (RSES). To create a cutoff point for satisfaction with the GSI, the item response theory and the classic test theory were used. OutcomesMale's (i) GSI, (ii) sexual function, (iii) body appreciation, and (iv) self-esteem were assessed. ResultsIn this study, 518 men with a mean age of 33.90 (±13.83) years participated. The Brazilian version of MGSIS demonstrated good content validity and a single factor that explained 64.57% of the variance. Cronbach's α and ICC values were 0.905 and 0.806, respectively. By assessing measurement errors, we found no systematic bias in the sample. MGSIS showed a moderate to weak correlation with IIEF, BAS-2 and RSES. A cut-off point of 23 in the MGSIS total score was found to rate satisfaction with the GSI. Clinical TranslationMGSIS is a valid and reliable measurement instrument for measuring male GSI in Brazil. Strengths and LimitationsThis study evaluated the measurement properties of MGSIS according to COSMIN, which is a powerful and useful guideline for measurement properties. However, due to the lack of a gold standard for measuring the GSI, we have not assessed the criterion validity. ConclusionMGSIS is valid, reliable and can be useful to assess the GSI and classify the satisfaction with the GSI of Brazilian men.de Arruda GT, da Silva EV, Braz MM. Male Genital Self-Image Scale (MGSIS): Cutoff Point, Cultural Adaptation and Validation of Measurement Properties in Brazilian Men. J Sex Med 2021;18:1759–1767.