Test-retest Study Research Articles

Improving MR axon radius estimation in human white matter using spiral acquisition and field monitoring.

To compare MR axon radius estimation in human white matter using a multiband spiral sequence combined with field monitoring to the current state-of-the-art echo-planar imaging (EPI)-based approach. A custom multiband spiral sequence was used for diffusion-weighted imaging at ultra-high -values. Field monitoring and higher order image reconstruction were employed to greatly reduce artifacts in spiral images. Diffusion weighting parameters were chosen to match a state-of-the art EPI-based axon radius mapping protocol. The spiral approach was compared to the EPI approach by comparing the image signal-to-noise ratio (SNR) and performing a test-retest study to assess the respective variability and repeatability of axon radius mapping. Effective axon radius estimates were compared over white matter voxels and along the left corticospinal tract. Increased SNR and reduced artifacts in spiral images led to reduced variability in resulting axon radius maps, especially in low-SNR regions. Test-retest variability was reduced by a factor of approximately 1.5 using the spiral approach. Reduced repeatability due to significant bias was found for some subjects in both spiral and EPI approaches, and attributed to scanner instability, pointing to a previously unknown limitation of the state-of-the-art approach. Combining spiral readouts with field monitoring improved mapping of the effective axon radius compared to the conventional EPI approach.

COPD empowerment scale: a scale development and validatıon study

Abstract Background The fact that COPD symptoms seriously affect daily life makes it different from other chronic diseases. The purpose of this study was to develop the COPD Empowerment Scale and test its psychometric properties. Methods This study, carried out with a methodological design, was carried out in a Chest Diseases Hospital in Istanbul, Turkey, between June 2023 and March 2024. A scale item pool was created by literature review and semi-structured interviews with COPD patients, and opinions were obtained from 16 experts. The draft scale, consisting of 55 items, was applied to 30 COPD patients as a pilot study. The draft scale was applied to 275 COPD patients and its psychometric properties were tested. The validity of the scale was evaluated by Content Validity Index (CGI) and exploratory and confirmatory factor analysis. Its reliability was evaluated by internal consistency analysis (Cronbach Alpha coefficient), item-total score correlations and test-retest analyses. Statistical significance level was accepted as p < 0.05. Results The KGI of the scale was found to be 0.97. The draft scale was transformed into a scale with five sub-dimensions and 31 items as a result of exploratory factor analysis. Cronbach’s Alpha value of the total scale is 0.896, and its sub-dimensions Cronbach’s Alpha values are; knowledge and understanding was found to be 0.731, access to health services was 0.816, self-efficacy was 0.719, symptom management was 0.842, and psycho-social coping was 0.728. Factor loadings of all items were 0.40 and above. As a result of confirmatory factor analysis, χ2 /df (2.59), RMSEA (0.076), NFI (0.92), NNFI (0.95), SRMR (0.03) and CFI (0.95) measurements are within the desired fit values. In the test-retest reliability study of the scale, the Pearson moment correlation coefficient was found to be rᵪᵪ=.996 (p<.01). Conclusions The COPD empowerment scale was found to be psychometrically valid and reliable. Key messages • The developed scale is a valid and reliable tool to determine the reinforcement needs of COPD patients. • The scale can be used to evaluate the effectiveness of empowerment initiatives.

Turkish validity and reliability study of the Baby-Led Weaning Scale

AimThe aim of this study was to test the psychometric properties of the Turkish version of the Baby-Led Weaning Scale for parents with babies/children aged from 6 to 30 months. MethodsThe sample for this methodological research consisted of parents with babies aged 6 to 30 months between March and June 2024 in a city in eastern Turkey. The data were collected from 354 parents for exploratory factor analysis, from 213 parents for confirmatory factor analysis, and from 70 for the test-retest reliability study. The data were collected using the “Descriptive Information Form”, the “Baby-Led Weaning Scale” and the “Transition to Complementary Feeding Behaviors Scale” (TCFBS). ResultsThe total content validity index score of the Baby Led Weaning Scale was 0.92 and the content validity rate score was 0.92. The TCBFS was used for the concordance of the scale with similar scales. During the measurements, the intra-observer reliability of the Baby Led Weaning Scale was statistically significant (p < 0.001). The Exploratory Factor Analysis revealed a three-factor structure, explaining 611.5 % of the variance. The fix index values were χ2/df = 3.036, RMSEA = 0.069, GFI = 0.902, CFI = 0.907 and AGFI = 0.857, IFI = 0.928, and TLI = 0.921.The Cronbach alpha values of the scale were in the range of 0.706 and 0.831. ConclusionAs a result, the Turkish adaptation of the Baby Led Weaning Scale is a valid and reliable measurement tool. Practical implicationsThe Baby-Led Weaning Scale can be used as a simple and objective tool to measure the knowledge level of parents with babies/children aged 6 to 30 months.

Threshold and Standard Error of Measurement for Relative Rest Time of Pericervical Muscles During Prolonged Computer-Typing Tasks in Individuals With Neck Symptoms.

Introduction The most common work-related musculoskeletal disorder worldwide is neck pain, especially among individuals who extensively use computers in a seated position. One biomedical cause of this neck pain is the prolonged activity of the muscles around the neck. Electromyography (EMG) has been used to evaluate the frequency and intensity of muscle activity. "Relative rest time (RRT)" is an index derived indicating the proportion of time below a certain threshold to the total task time. This study aimed to investigate the measurement errors and minimum detectable change (MDC) of RRT of the pericervical muscles during prolonged typing tasks in individuals with neck symptoms and to examine the differences in measurement errors at 3 µV and 6 µV thresholds. Methods This test-retest reliability study was conducted twice with a one-week interval to examine measurement errors of the RRT using surface EMG. The number of participants was set to 30 subjects who had neck symptoms with a Neck Disability Index of 16% or higher. The primary outcome measure was RRT of the following: the pericervical muscles of the right side during a 60-minute typing task; the splenius capitis muscle, upper trapezius (UT) muscle, middle trapezius muscle, sternocleidomastoid muscle, serratus anterior muscle, longissimus muscle, and pectoralis major muscle. RRT was calculated as the percentage of time that muscle activity was below the threshold for more than 0.250 seconds continuously during a 60-minute typing task. The standard error of measurement (SEM) and MDC were calculated with the two thresholds of 3 µV and 6 µV. The SEMs of the two thresholds were compared using a paired method. Results Ultimately, the data of 26 participants were analyzed. The SEM (MDC) values of the RRT at the 3 µV and 6 µV thresholds were 19.22 (53.27) and 9.52 (26.39) for the splenius capitis muscle, 3.24 (8.97) and 0.38 (1.05) for the sternocleidomastoid muscle, 15.47 (42.88) and 18.79 (52.08) for the UT muscle, 21.28 (58.99) and 2.28 (6.32) for the middle trapezius muscle, 13.67 (37.90) and 11.64 (32.27) for the serratus anterior muscle, 16.81 (46.60) and 3.32 (9.20) for the longissimus muscle, and 8.97 (24.87) and 4.24 (11.74) for the pectoralis major muscle, respectively. The SEMs of the RRT with the 6 µV threshold were statistically significantly lower than those with the 3 µV threshold in all pericervical muscles, except for the UT muscle. Conclusion This study identified the SEM and MDC of the RRT for the pericervical muscles during prolonged typing tasks in individuals with neck symptoms. Except for the UT muscle, the SEMs of the RRT with the 6 µV threshold were statistically smaller than those with the 3 µV threshold. Therefore, when using the RRT in intervention studies that aim to reduce muscle activity during typing in those with neck symptoms, the 6 µV threshold measurement would be recommended for the RRT of the pericervical muscles except for the UT muscle.

Repeatability and minimal detectable change including clothing effects for smartphone-based 3D markerless motion capture

OpenCap, a smartphone- and web-based markerless system, has shown acceptable accuracy compared to marker-based systems, but lacks information on repeatability. This study fills this gap by evaluating the intersession repeatability of OpenCap and investigating the effects of clothing on gait kinematics. Twenty healthy volunteers participated in a test–retest study, performing walking and sit-to-stand tasks with minimal clothing and regular street wear. Segment lengths and lower-limb kinematics were compared between both sessions and for both clothing conditions using the root-mean-square-deviation (RMSD) for entire waveforms and the standard error of measurement (SEM) and minimal detectable change (MDC) for discrete kinematic parameters. In general, the RMSD test–retest values were 2.8 degrees (SD: 1.0) for walking and 3.3 degrees (SD: 1.2) for sit-to-stand. The highest intersession variability was observed in the trunk, pelvis, and hip kinematics of the sagittal plane. SEM and MDC values were on average 2.2 and 6.0 degrees, respectively, for walking, and 2.4 and 6.5 degrees for sit-to-stand. Clothing had minimal effects on kinematics by adding on average less than one degree to the RMSD values for most variables. The segment lengths showed moderate to excellent agreement between both sessions and poor to moderate agreement between clothing conditions. The study highlights the reliability of OpenCap for markerless motion capture, emphasizing its potential for large-scale field studies. However, some variables showed high MDC values above 5 degrees and thus warrant further enhancement of the technology. Although clothing had minimal effects, it is still recommended to maintain consistent clothing to minimize overall variability.

Absolute and Relative Reliability of Spatiotemporal Gait Characteristics Extracted from an Inertial Measurement Unit among Senior Adults Using a Passive Hip Exoskeleton: A Test-Retest Study.

Seniors wearing a passive hip exoskeleton (Exo) show increased walking speed and step length but reduced cadence. We assessed the test-retest reliability of seniors' gait characteristics with Exo. Twenty seniors walked with and without Exo (noExo) on a 10 m indoor track over two sessions separated by one week. Speed, step length, cadence and step time variability were extracted from one inertial measurement unit (IMU) placed over the L5 vertebra. Relative and absolute reliability were assessed using the intraclass correlation coefficient (ICC), standard error of measurement (SEM) and minimal detectable change (MDC). The relative reliability of speed, step length, cadence and step time variability ranged from "almost perfect to substantial" for Exo and noExo with ICC values between 0.75 and 0.87 and 0.60 and 0.92, respectively. The SEM and MDC values for speed, step length cadence and step time variability during Exo and noExo were <0.002 and <0.006 m/s, <0.002 and <0.005 m, <0.30 and <0.83 steps/min and <0.38 s and <1.06 s, respectively. The high test-retest reliability of speed, step length and cadence estimated from IMU suggest a robust extraction of spatiotemporal gait characteristics during exoskeleton use. These findings indicate that IMUs can be used to assess the effects of wearing an exoskeleton on seniors, thus offering the possibility of conducting longitudinal studies.

EVALUATION OF INDONESIAN VERSION OF THE EMOTION WORD FLUENCY TEST

A cognitive assessment is not complete without an inspection of a client’s emotional status. The Emotion Word Fluency Test (EWFT) is a newly developed instrument for Indonesia. It provides similar assessment to other semantic word fluency tasks, linguistic and memory skills, and also a client’s current emotional standing and previously experienced emotions. Our study aims to present the newly-developed EWFT and its scoring system, and the psychometric properties of the test including its test-retest reliability and construct validity, as well as the reliability of the scoring system. Healthy participants with no history of brain-related diseases (n = 98), varying in age and education, were recruited; an additional group (n = 30) was included in the test-retest reliability study. The construct validity was evaluated with a phonemic verbal fluency test (pVFT). The EWFT was correlated (.51-.56) with the pVFT, and the three subscales of the pVFT correlated highly (.75-.80), indicating that the EWFT and pVFT share a common construct, but are also different. The scoring system showed excellent reliability (.86 for the number of correct generated words), and the test-retest reliability for the number of correct words was moderate (.54). Participants produced more negative than positive emotion words, t(29) = 6.33, p &lt; .05. The correlation between the number of positive and negative emotion words was zero. Age affected the performance in both EWFT, F(3, 80) = 3.10, p &lt; .05; and pVFT F(3, 80) = 2.47, p &lt; .05; as was internationally reported. The EWFT scoring system is concluded reliable and the test has moderate reliability.

Computational phenotyping of aberrant belief updating in individuals with schizotypal traits and schizophrenia

BackgroundPsychotic experiences are thought to emerge from various interrelated patterns of disrupted belief updating, such as overestimating the reliability of sensory information and misjudging task volatility. Yet, these substrates have never been jointly addressed under one computational framework and it is not clear to what degree they reflect trait-like computational patterns. MethodsWe introduced a novel hierarchical Bayesian model that describes how individuals simultaneously update their beliefs about the task volatility and noise in observation. We applied this model to data from a modified Predictive inference task in a test-retest study with healthy volunteers (N=45, 4 sessions) and examined the relationship between model parameters and schizotypal traits in a larger online sample (N = 437) and in a cohort of patients with schizophrenia (N = 100). ResultsThe interclass correlations were moderate to high for model parameters and excellent for averaged belief trajectories and precision-weighted learning rates estimated through hierarchical Bayesian inference. We found that uncertainty about the task volatility was related to schizotypal traits and to positive symptoms in patients, when learning to gain rewards. In contrast, negative symptoms in patients were associated with more rigid beliefs about observational noise, when learning to avoid losses. ConclusionThese findings suggest that individuals with schizotypal traits across the psychosis continuum are less likely to learn or utilize higher-order statistical regularities of the environment and showcase the potential of clinically relevant computational phenotypes for differentiating symptom groups in a transdiagnostic manner.

Reliability of cervicocephalic sense of force

Cervicocephalic proprioception (CCP) is an important assessment item for people with a range of clinical conditions, where reduced CCP is associated with neck pain and imbalance. Reliability has been established for a range of positional and movements tests, but there is limited data regarding sense of force, particularly across three planes of movement. The current test–retest study assessed reliability when evaluating sense of force in healthy adults (8 males, 6 females, mean age 31.50 years [SD 10.14]) over two sessions, 4–7 days apart. A force matching protocol was used to evaluate reliability of absolute error (AE), constant error (CE), and variable error (VE) for 10 % and 25 % maximal voluntary contraction (MVC) target forces for flexion, extension, lateral flexion, and rotation. Participants were strapped to a chair to limit trunk movement and data was captured using a compressive force transducer fixed to an adjustable wall mount. Six trials were performed for each contraction-type, totaling 72 submaximal MVCs per session. ICC estimates for AE (0.15–0.77), CE (0.01–0.85), and VE (0.00–0.83) were varied and confidence intervals were mostly wide. Considering lower limits of confidence intervals, CE had best reliability values generally, but more specifically the most reliable contraction type and movement was 25 % MVC flexion (ICC 0.85, confidence interval 0.54–0.95). This study found that reliability for sense of force testing was dependent upon contraction, type of error, and target force utilized. Further reliability analysis should be performed when applying this test to measure validity outcomes in clinical populations.

Cultivating Patient Preferences in ALS Clinical Trials: Reliability and Prognostic Value of the Patient-Ranked Order of Function.

The Patient-Ranked Order of Function (PROOF) is a novel approach to account for patient-reported preferences in the evaluation of treatments of amyotrophic lateral sclerosis (ALS). In this study, we assess the reliability and prognostic value of different sets of patient-reported preferences that can be used for the PROOF end point. Data were obtained through online surveys over the course of 12 months using the population-based registry of the Netherlands. Patients were asked to score functional domains of the ALS Functional Rating Scale (ALSFRS-R) and rank the order of importance of each domain. Two weeks after the initial invite, the questionnaire was repeated to evaluate test-retest reliability. Vital status was extracted from the municipal population register. In total, 611 patients with ALS were followed up for survival and 382 patients were included in the test-retest reliability study. All versions of PROOF, using different sets of preferences, resulted in excellent reliability (intraclass correlation coefficients ranged from 0.89 [95% CI 0.87-0.91] to 0.97 [95% CI 0.97-0.98], all p < 0.001), without systematic differences between baseline and week 2 (mean rank difference range -1 to -3 [95% CI range -8 to 2], all p > 0.20). Preferences about future events were more variable than preferences about current symptoms. All versions of PROOF strongly predicted overall survival (hazard ratios per 10th rank percentile ranged from 0.80 to 0.83 [95% CI range 0.76-0.87], all p < 0.001) and had a more even separation of survival curves between rank-stratified subgroups compared with the ALSFRS-R total score. In a large cohort of patients, we show how patient-reported preferences can be measured and integrated reliably with the ALSFRS-R without leading to systematic bias. Patient preferences may provide unique prognostic information in addition to what is already measured conventionally. This could provide a more comprehensive understanding of how medical interventions effectively address the patient's concerns and improve what matters most to them.

The WOUND-Q Function and Symptoms Scales for Chronic Lower Extremity Wounds: A Validation Study.

Objective: Determine the validity and reliability of the LIMB-Q scales, Function, and Symptoms in patients with chronic lower extremity wounds. Approach: Cognitive debriefing interviews with people with current or previous wounds were conducted to examine content validity. Scales were field-tested in an international sample of people with chronic lower extremity wounds sourced from an online platform (i.e., Prolific). Psychometric properties were examined using the Rasch Measurement Theory analysis. A test-retest reproducibility study was performed, and construct validity was examined. Results: Content validity was established after 10 cognitive interviews. A total of 233 people with lower extremity wounds (age 19-80 years, mean 39.3) participated in the field test. All 25 items tested demonstrated good fit to the Rasch model with ordered thresholds. One item had a fit residual outside ±2.5, but no items had significant χ2 values after Bonferroni adjustment. Reliability was high with the person separation index, Cronbach alpha, and intraclass correlation coefficient values >0.8. Strong correlations were found between the Function and Symptoms scales and EQ-5D dimensions measuring similar constructs as well as the EQ-5D global score. All hypotheses for construct validity were confirmed. Innovation: Patient-reported outcome measures are an important component of patient-centered care, as they capture the patient's perspective in a rigorous and reproducible way. Adding these two scales to the WOUND-Q provides a means to measure function and symptoms associated with lower extremity wounds. Conclusion: These new WOUND-Q scales can be used to measure outcomes important to patients with lower extremity wounds in clinical settings and research studies.

Validation of quantitative magnetic resonance imaging techniques in head and neck healthy structures involved in the salivary and swallowing function: Accuracy and repeatability

Background and PurposeRadiation-induced damage to the organs at risk (OARs) in head-and-neck cancer (HNC) patient can result in long-term complications. Quantitative magnetic resonance imaging (qMRI) techniques such as diffusion-weighted imaging (DWI), DIXON for fat fraction (FF) estimation and T2 mapping could potentially provide a spatial assessment of such damage. The goal of this study is to validate these qMRI techniques in terms of accuracy in phantoms and repeatability in-vivo across a broad selection of healthy OARs in the HN region. Materials and MethodsScanning was performed at a 3 T diagnostic MRI scanner, including the calculation of apparent diffusion coefficient (ADC) from DWI, FF and T2 maps. Phantoms were scanned to estimate the qMRI techniques bias using Bland-Altman statistics. Twenty-six healthy subjects were scanned twice in a test–retest study to determine repeatability. Repeatability coefficients (RC) were calculated for the parotid, submandibular, sublingual and tubarial salivary glands, oral cavity, pharyngeal constrictor muscle and brainstem. Additionally, a linear mixed-effect model analysis was used to evaluate the effect of subject-specific characteristics on the qMRI values. ResultsBias was 0.009x10-3 mm2/s for ADC, -0.7 % for FF and -7.9 ms for T2. RCs ranged 0.11–0.25x10-3 mm2/s for ADC, 1.2–6.3 % for FF and 2.5–6.3 ms for T2. A significant positive linear relationship between age and the FF and T2 for some of the OARs was found. ConclusionThese qMRI techniques are feasible, accurate and repeatable, which is promising for treatment response monitoring and/or differentiating between healthy and unhealthy tissues due to radiation-induced damage in HNC patients.

A review of longitudinal studies on flashbulb memories. Where we started, are, and are going?

AbstractSince Brown and Kulik (1977) coined the term ‘Flashbulb memories’ (FBMs), there are still heated debates about their nature. We thus considered it useful to take stock of almost 50 years of research by reviewing 57 test–retest studies on FBMs for public events. The review aimed to answer six research questions by examining the target events and populations investigated (RQ1); the methods used to assess differences among groups and the effect of time on memory (RQ2); the assessment of FBMs' contents (RQ3), consistency (RQ4), vividness and confidence (RQ5); the criteria used to draw studies' conclusions (RQ6). Results show a huge methodological heterogeneity which may have contributed to the different conclusions about the special status of FBMs. The in‐depth comparison of 9/11 studies suggests that results may differ depending on the methods used. Finally, the paper provides methodological suggestions for future FBMs studies and seeks to stimulate critical theoretical reflections.

New improved radiometabolite analysis method for [18F]FTHA from human plasma: a test-retest study with postprandial and fasting state

BackgroundFatty acid uptake can be measured using PET and 14-(R,S)‐[18F]fluoro‐6‐thia‐heptadecanoic acid ([18F]FTHA). However, the relatively rapid rate of [18F]FTHA metabolism significantly affects kinetic modeling of tissue uptake. Thus, there is a need for accurate chromatographic methods to analyze the unmetabolized [18F]FTHA (parent fraction). Here we present a new radiometabolite analysis (RMA) method, with comparison to a previous method for parent fraction analysis, and its use in a test-retest clinical study under fasting and postprandial conditions. We developed a new thin-layer chromatography (TLC) RMA method for analysis of [18F]FTHA parent fraction and its radiometabolites from plasma, by testing stationary phases and eluent combinations. Next, we analyzed [18F]FTHA, its radiometabolites, and plasma radioactivity from subjects participating in a clinical study. A total of 17 obese or overweight participants were dosed with [18F]FTHA twice under fasting, and twice under postprandial conditions and plasma samples were obtained between 14 min (mean of first sample) and 72 min (mean of last sample) post-injection. Aliquots of 70 plasma samples were analyzed using both methods, enabling head-to-head comparisons. We performed test-retest and group comparisons of the parent fraction and plasma radioactivity.ResultsThe new TLC method separated seven [18F]FTHA radiometabolite peaks, while the previous method separated three. The new method revealed at least one radiometabolite that was not previously separable from [18F]FTHA. From the plasma samples, the mean parent fraction value was on average 7.2 percentage points lower with the new method, compared to the previous method. Repeated [18F]FTHA investigations on the same subject revealed reproducible plasma SUV and parent fractions, with different kinetics between the fasted and postprandial conditions.ConclusionsThe newly developed improved radio-TLC method for [18F]FTHA RMA enables accurate parent fraction correction, which is required to obtain quantitative data for modelling [18F]FTHA PET data. Our test-retest study of fasted and postprandial conditions showed robust reproducibility, and revealed clear differences in the [18F]FTHA metabolic rate under different study settings.Trial registrationEudraCT No: 2020-005211-48, 04Feb2021; and Clinical Trials registry NCT05132335, 29Oct2021, URL: https://classic.clinicaltrials.gov/ct2/show/NCT05132335.

Time-varying functional connectivity as Wishart processes

Abstract We investigate the utility of Wishart processes (WPs) for estimating time-varying functional connectivity (TVFC), which is a measure of changes in functional coupling as the correlation between brain region activity in functional magnetic resonance imaging (fMRI). The WP is a stochastic process on covariance matrices that can model dynamic covariances between time series, which makes it a natural fit to this task. Recent advances in scalable approximate inference techniques and the availability of robust open-source libraries have rendered the WP practically viable for fMRI applications. We introduce a comprehensive benchmarking framework to assess WP performance compared with a selection of established TVFC estimation methods. The framework comprises simulations with specified ground-truth covariance structures, a subject phenotype prediction task, a test-retest study, a brain state analysis, an external stimulus prediction task, and a novel data-driven imputation benchmark. The WP performed competitively across all the benchmarks. It outperformed a sliding window (SW) approach with adaptive cross-validated window lengths and a dynamic conditional correlation (DCC)-multivariate generalized autoregressive conditional heteroskedasticity (MGARCH) baseline on the external stimulus prediction task, while being less prone to false positives in the TVFC null models.

Two-year retest reliability and predictive validity of the Self- and Informant-Personality Inventory for ICD-11 in older adults.

The International Classification of Diseases, 11th edition (ICD-11) adopted a fully dimensional model of personality disorder. The Personality Inventory for ICD-11 (PiCD) and Informant-Personality Inventory for ICD-11 (IPiC) were developed to assess the ICD-11 trait model, and the PiCD has since received significant validation support. However, there has only been one prior study of longitudinal predictive validity of the PiCD, two relatively short test-retest reliability studies of the PiCD, and no prior longitudinal tests of the IPiC. Longitudinal psychometric support for psychological assessment measures is essential. The present study provides a longer, larger, 2-year psychometric validation test of the PiCD and IPiC. Participants (N = 711) and their informants (N = 569) were recruited in the St. Louis Personality and Aging Network. The results demonstrated strong 2-year retest reliability for the PiCD and IPiC, as well as mean-level stability. Additionally, we explored the relationships between the PiCD and IPiC and important life outcome measures (depressive symptoms, satisfaction with life, and health status). The analysis revealed several significant associations between PiCD and IPiC scales and the outcome variables across time. Further, the PiCD Negative Affectivity and IPiC Detachment scales demonstrated incremental validity over each other and the outcome variables at Wave 1 in the prediction of depressive symptoms and satisfaction with life, respectively. The findings provide essential longitudinal test-retest reliability and predictive validity support for the PiCD and IPiC. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Simultaneous assessment of blood flow and myelin content in the brain white matter with dynamic [11C]PiB PET: a test-retest study in healthy controls.

Exploring the relationship between oxygen supply and myelin damage would benefit from a simultaneous quantification of myelin and cerebral blood flow (CBF) in the brain's white matter (WM). To validate an analytical method for quantifying both CBF and myelin content in the WM using dynamic [11C]PiB positron emission tomography (PET). A test-retest study was performed on eight healthy subjects who underwent two consecutive dynamic [11C]PiB-PET scans. Three quantitative approaches were compared: simplified reference tissue model 2 (SRTM2), LOGAN graphical model, and standardized uptake value ratio (SUVR). The sensitivity of methods to the size of the region of interest was explored by simulating lesion masks obtained from 36 subjects with multiple sclerosis. Reproducibility was assessed using the relative difference and interclass correlation coefficient. Repeated measures correlations were used to test for cross-correlations between metrics. Among the CBF measures, the relative delivery (R1) of the simplified reference tissue model 2 (SRTM2) displayed the best reproducibility in the white matter, with a strong influence of the size of regions analyzed, the test-retest variability being below 10% for regions above 68 mm3 in the supratentorial white matter. [11C]PiB PET-derived proxies of CBF demonstrated lower perfusion of white matter compared to grey matter with an overall ratio equal to 1.71 ± 0.09 when the SRTM2-R1 was employed. Tissue binding in the white matter was well estimated by the Logan graphical model through estimation of the distribution volume ratio (LOGAN-DVR) and SRTM2 distribution volume ratio (SRTM2-DVR), with test-retest variability being below 10% for regions exceeding 106 mm3 for LOGAN-DVR and 300 mm3 for SRTM2-DVR. SRTM2-DVR provided a better contrast between white matter and grey matter. The interhemispheric variability was also dependent on the size of the region analyzed, being below 10% for regions above 103 mm3 for SRTM2-R1 and above 110 mm3 for LOGAN-DVR. Whereas the 1 to 8-minute standardized uptake value ratio (SUVR1-8) showed an intermediary reproducibility for CBF assessment, SUVR0-2 for perfusion or SUVR50-70 for tissue binding showed poor reproducibility and correlated only mildly with SRTM2-R1 and LOGAN-DVR estimations respectively. [11C]PiB PET imaging can simultaneously quantify perfusion and myelin content in WM diseases associated with focal lesions. For longitudinal studies, SRTM2-R1 and DVR should be preferred over SUVR for the assessment of regional CBF and myelin content, respectively. European Union Clinical Trials Register EUDRACT; EudraCT Number: 2008-004174-40; Date: 2009-03-06; https//www.clinicaltrialsregister.eu ; number 2008-004174-40.

Reliability and validity of the Japanese version of the Pregnancy and Weight Gain Attitude Scale.

This study aimed to develop the Japanese version of the Pregnancy and Weight Gain Attitude Scale (J-PWGAS) as a measurement of body image regarding body weight and shape during pregnancy. This cross-sectional study was conducted at a perinatal medical center in Osaka, Japan, between March and November 2020. We recruited pregnant women in their second or third trimester, who were 20 years old or older and without pregnancy complications. This study evaluated the criterion validity, construct validity, internal consistency, and test-retest reliability. Of the participants, 218 and 102 women participated in the validation and test-retest reliability studies, respectively. An exploratory factor analysis revealed a 17-item, five-factor structure. The J-PWGAS indicated acceptable criterion validity, internal consistency, and test-retest reliability. The J-PWGAS can measure attitudes toward gestational weight gain in Japanese pregnant women and would be useful in examining the association of body image with weight gain and psychological status during pregnancy.

Precision brain morphometry using cluster scanning

Abstract Measurement error limits the statistical power to detect group differences and longitudinal change in structural MRI morphometric measures (e.g., hippocampal volume, prefrontal cortical thickness). Recent advances in scan acceleration enable extremely fast T1-weighted scans (~1 minute) that achieve morphometric errors that are close to the errors in longer traditional scans. As acceleration allows multiple scans to be acquired in rapid succession, it becomes possible to pool estimates to increase measurement precision, a strategy known as “cluster scanning.” Here, we explored brain morphometry using cluster scanning in a test-retest study of 40 individuals (12 younger adults, 18 cognitively unimpaired older adults, and 10 adults diagnosed with mild cognitive impairment or Alzheimer’s Dementia). Morphometric errors from a single compressed sensing (CS) 1.0 mm scan (CS) were, on average, 12% larger than a traditional scan using the Alzheimer’s Disease Neuroimaging Initiative (ADNI) protocol. Pooled estimates from four clustered CS acquisitions led to errors that were 34% smaller than ADNI despite having a shorter total acquisition time. Given a fixed amount of time, a gain in measurement precision can thus be achieved by acquiring multiple rapid scans instead of a single traditional scan. Errors were further reduced when estimates were pooled from eight CS scans (51% smaller than ADNI). Neither pooling across a break nor pooling across multiple scans of different spatial resolutions boosted this benefit. We discuss the potential of cluster scanning to improve morphometric precision, boost statistical power, and produce more sensitive disease progression biomarkers.

Evaluation of the Oral Hygiene Ability Instrument (OHAI): Test of reliability.

To evaluate the reliability of the new Oral Hygiene Ability Instrument (OHAI) developed to assess the cause of any inability for older adults to manage oral hygiene self-care. Oral hygiene is an important part of oral health. The inability to manage oral hygiene, combined with other risk factors, often results in poor oral health and impaired quality of life. A reliable OHAI could benefit preventive oral health care. The preliminary OHAI uses 33 items in three parts: (I) interview, (II) clinical examination and (III) observation of oral hygiene activities. A total of 37 older adults participated in a test-retest study of Part I. Inclusion criteria were age ≥ 65 years, have at least one tooth and be able to oral hygiene self-care. The intra- and inter-rater reliability of parts II and III used films and photographs of OHAI assessments of 15 different individuals. These films/photographs were assessed twice by four dental professionals who had participated in the OHAI data collection. For statistical analyses of the reliability, per cent agreement, Krippendorff's alpha and E. Svensson's method were used. The test-retest for Part I items showed acceptable-to-good agreement and no systematic disagreement. In Part II, two items showed somewhat limited reliability. Part III showed good intra- and inter-rater reliability. The OHAI items seem stable and reliable for the intended sample, and the instrument may be a valuable tool to identify older adults at risk of impaired oral health. However, two items may need to be reformulated.