Test-retest Protocol Research Articles

Test-Retest Reliability of the Verran Professional Governance Scale©.

Background and Purpose: Stability testing, conducted using a test-retest protocol, measures an instrument's reliability by evaluating the consistency of participant responses to survey questions with repeated testing within a short interval. No studies have measured the stability of the Verran Professional Governance Scale© (VPGS). The purpose of this study was to evaluate the test-retest reliability of the VPGS. Methods: Volunteers from a parent study using the VPGS were sent a link to a retest version of the survey 14 days after taking the initial survey with a reminder email sent 5 days after the first request. Item-level and subscale comparisons were made between participants' initial and retest responses using intraclass correlation coefficients (ICCs) applying a two-way random-effects model. Results: VPGS subscales had ICC scores of 0.71 for decision-making, 0.73 for collateral relationships, and 0.86 for professional obligation. Conclusions: Findings suggest that the VPGS demonstrates test-retest reliability. Future research should evaluate the instrument's responsiveness.

Test-Retest Repeatability of Patlak Slopes versus Standardized Uptake Values for Hypermetabolic Lesions and Normal Organs in an Oncologic PET/CT Population.

We aimed to determine the test-retest repeatability of quantitative metrics based on the Patlak slope (PS) versus the standardized uptake value (SUV) among lesions and normal organs on oncologic [18F]FDG-PET/CT. This prospective, single-center study enrolled adults undergoing standard-of-care oncologic [18F]FDG-PET/CTs. Early (35-50min post-injection) and late (75-90min post-injection) SUV and PS images were reconstructed from dynamic whole-body PET data. Repeat imaging occurred within 7days. Relevant quantitative metrics were extracted from lesions and normal organs. Repeatability was assessed via mean test-retest percent changes [T-RT %Δ], within-subject coefficients of variation (wCVs), and intra-class correlation coefficients (ICCs). Nine subjects (mean age, 61.7 ± 6.2years; 6 females) completed the test-retest protocol. Four subjects collectively had 17 [18F]FDG-avid lesions. Lesion wCVs were higher (i.e., worse repeatability) for PS-early-max (16.2%) and PS-early-peak (15.6%) than for SUV-early-max (8.9%) and SUV-early-peak (8.1%), with similar early metric ICCs (0.95-0.98). Lesion wCVs were similar for PS-late-max (8.5%) and PS-late-peak (6.4%) relative to SUV-late-max (9.7%) and SUV-late-peak (7.2%), with similar late metric ICCs (0.93-0.98). There was a significant bias toward higher retest SUV and PS values in the lesion analysis (T-RT %Δ [95% CI]: SUV-late-max, 10.0% [2.6%, 17.0%]; PS-late-max, 20.4% [14.3%, 26.4%]) but not in the normal organ analysis. Among [18F]FDG-avid lesions, the repeatability of PS-based metrics is similar to equivalent SUV-based metrics at late post-injection time points, indicating that PS-based metrics may be suitable for tracking response to oncologic therapies. However, further validation is required in light of our study's limitations, including small sample size and bias toward higher retest values for some metrics.

Mobile version of the Battery for the Assessment of Auditory Sensorimotor and Timing Abilities (BAASTA): Implementation and adult norms.

Timing and rhythm abilities are complex and multidimensional skills that are highly widespread in the general population. This complexity can be partly captured by the Battery for the Assessment of Auditory Sensorimotor and Timing Abilities (BAASTA). The battery, consisting of four perceptual and five sensorimotor tests (finger-tapping), has been used in healthy adults and in clinical populations (e.g., Parkinson's disease, ADHD, developmental dyslexia, stuttering), and shows sensitivity to individual differences and impairment. However, major limitations for the generalized use of this tool are the lack of reliable and standardized norms and of a version of the battery that can be used outside the lab. To circumvent these caveats, we put forward a new version of BAASTA on a tablet device capable of ensuring lab-equivalent measurements of timing and rhythm abilities. We present normative data obtained with this version of BAASTA from over 100 healthy adults between the ages of 18 and 87 years in a test-retest protocol. Moreover, we propose a new composite score to summarize beat-based rhythm capacities, the Beat Tracking Index (BTI), with close to excellent test-retest reliability. BTI derives from two BAASTA tests (beat alignment, paced tapping), and offers a swift and practical way of measuring rhythmic abilities when research imposes strong time constraints. This mobile BAASTA implementation is more inclusive and far-reaching, while opening new possibilities for reliable remote testing of rhythmic abilities by leveraging accessible and cost-efficient technologies.

Validation of self-reported articulatory oral motor skill against objectively measured repetitive articulatory rate in community-dwelling older Japanese adults: The Otassha Study.

To assess the validity of self-reported articulatory oral motor skill against objectively measured repetitive articulatory rate (oral diadochokinesis [oral-DDK]) as a gold standard index for articulatory oral motor skill in community-dwelling older Japanese adults. This cross-sectional study included 607 Japanese adults (mean age = 73.9 years). A single-item self-report questionnaire for articulatory oral motor skill was developed. Study participants completed a 1-month-interval test-retest protocol to assess reliability of the questionnaire, and the protocol was tested by the kappa statistic. Oral-DDK with /ta/ (i.e., the number of repetitions of the monosyllable /ta/ per second) was measured during the on-site examination. Low oral-DDK performance was defined as <5.2 times/s in men and <5.4 times/s in women. Oral-DDK performance, oral functions other than articulatory oral motor skill, and physical frailty were compared in the groups with and without self-reported low articulatory oral motor skill as determined by the response to the questionnaire. Self-reported low articulatory oral motor skill was identified in 18.5% of the study population. The self-report questionnaire had good test-retest reliability, with a kappa statistic of 0.71. Self-reported low articulatory oral motor skill was significantly associated with a lower value of oral-DDK with /ta/ and a higher proportion of low oral-DDK performance, difficulties in chewing and swallowing, dry mouth, and physical frailty. Self-report had high specificity (83.1%) but low sensitivity (42.1%) for detecting low oral-DDK performance. A single-item self-report questionnaire for articulatory oral motor skill had acceptable test-retest reliability and was associated with objectively measured articulatory oral motor skill. Geriatr Gerontol Int 2023; 23: 729-735.

Validity and Reliability of Short-Term Heart Rate Variability Parameters in Older People in Response to Physical Exercise.

Currently, and to the best of our knowledge, there is no standardized protocol to measure the effect of low- to moderate-intensity physical exercise on autonomic modulation focused in older people. Validate a test-retest short-term exercise protocol for measuring the autonomic response through HRV in older people. A test-retest study design was used. The participants were selected through intentional non-probabilistic sampling. A total of 105 older people (male: 21.9%; female: 78.1%) were recruited from a local community. The assessment protocol evaluated HRV before and immediately after the 2-min step test. It was performed twice on the same day, considering a time of three chronological hours between the two measurements. The posterior distribution of estimated responses in the Bayesian framework suggests moderate to strong evidence favoring a null effect between measurements. In addition, there was moderate to robust agreement between heart rate variability (HRV) indices and assessments, except for low frequency and very low frequency, which showed weak agreement. Our results provide moderate to strong evidence for using HRV to measure cardiac autonomic response to moderate exercise, suggesting that it is sufficiently reliable to show similar results to those shown in this test-retest protocol.

Reliability and validity of the incremental shuttle walk test in patients with fully ambulatory multiple sclerosis.

Functional exercise capacity evaluation is crucial to monitor treatment effects and disease progression in people with multiple sclerosis (pwMS). Compared to other tests, the incremental shuttle walking test (ISWT), which more accurately reflects cardiovascular responses, may be more useful for assessing exercise capacity. The aim of the study is to investigate the reliability and validity of the ISWT. Thirty-six pwMS with an Expanded Disability Status Scale (EDSS) score<4.5 between the ages of 25 and 65 were included in the study. The subjects underwent practice (ISWT-p) before undergoing the test-retest protocol in order to rule out the ISWT learning effect (ISWT-1 - ISWT-2). ISWT-1 and ISWT-2 were administered with a 3-7 day interval for test-retest reliability. Six-minutes walking test (6MWT) were applied for concurrent validity. The EDSS, pulmonary function tests, Fatigue Impact Scale (FIS), respiratory muscle strength [maximum inspiratory and expiratory pressure (MIP-MEP)] measurements were made for convergent validity. ISWT was found to have excellent test-retest reliability with an ICC value of 0.97. The area under the curve value was 0.904 indicating that ISWT has a good performance for predicting disease severity. The moderate correlation between ISWT and 6MWT (rho: 0.68, p<0,001) proved concurrent validity. It was also moderately correlated with EDSS, MEP (rho: -0.58 and 0.47 respectively), weakly correlated with MIP and FIS (rho:0.37 and -0.36, respectively) while not correlated with pulmonary function tests. The ISWT had excellent test-retest reliability, acceptable criterion and construct validity in ambulatory MS patients.

18F]F13640: a selective agonist PET radiopharmaceutical for imaging functional 5-HT1A receptors in humans

PurposeF13640 (a.k.a. befiradol, NLX-112) is a highly selective 5-HT1A receptor ligand that was selected as a PET radiopharmaceutical-candidate based on animal studies. Due to its high efficacy agonist properties, [18F]F13640 binds preferentially to functional 5-HT1A receptors, which are coupled to intracellular G-proteins. Here, we characterize brain labeling of 5-HT1A receptors by [18F]F13640 in humans and describe a simplified model for its quantification.MethodsPET/CT and PET-MRI scans were conducted in a total of 13 healthy male volunteers (29 ± 9 years old), with arterial input functions (AIF) (n = 9) and test–retest protocol (n = 8). Several kinetic models were compared (one tissue compartment model, two-tissue compartment model, and Logan); two models with reference region were also evaluated: simplified reference tissue model (SRTM) and the logan reference model (LREF).Results[18F]F13640 showed high uptake values in raphe nuclei and cortical regions. SRTM and LREF models showed a very high correlation with kinetic models using AIF. As concerns test–retest parameters and the prolonged binding kinetics of [18F]F13640, better reproducibility, and reliability were found with the LREF method. Cerebellum white matter and frontal lobe white matter stand out as suitable reference regions.ConclusionThe favorable brain labeling and kinetic profile of [18F]F13640, its high receptor specificity and its high efficacy agonist properties open new perspectives for studying functionally active 5-HT1A receptors, unlike previous radiopharmaceuticals that act as antagonists. [18F]F13640’s kinetic properties allow injection outside of the PET scanner with delayed acquisitions, facilitating the design of innovative longitudinal protocols in neurology and psychiatry.Trial Registration.Trial Registration EudraCT 2017–002,722-21.

Validation of the Dutch version of the 22-item Sino-Nasal Outcome Test (SNOT-22)

Background: The 22-item Sino-Nasal Outcome Test (SNOT-22) is a widely used questionnaire to measure disease-specific health-related quality of life in patients with chronic rhinosinusitis (CRS). The Dutch version has not been validated yet. Methods: The SNOT-22 was translated through a forward-backward translation technique and validated by a test-retest protocol in CRS patients, a responsiveness analysis in CRS patients treated with dupilumab, while using healthy individuals as controls. Results: The Dutch SNOT-22 showed excellent test-retest properties, good responsiveness to treatment with dupilumab, and a clear distinction between outcomes of CRS patients and healthy controls. Conclusion: The Dutch version of the SNOT-22 is a valid outcome measure in CRS patients.

Cross-cultural adaptation of the Moroccan version of the Mini-Mental State Examination: A preliminary study

Introduction The Mini-Mental State Examination (MMSE) is widely used for dementia screening. The purpose of this study was twofold. First, to cross-culturally adapt the Moroccan Arabic version of MMSE (MA-MMSE) to screen dementia among literate and illiterate elderly Moroccans, and second to analyze its psychometric properties. Methods The MA-MMSE was administered to 80 elderly patients, 28 were females and 52 were males. Among all the participants, 22 showed evidence of dementia. Receiver Operator Characteristic (ROC), internal consistency, and test–retest reliability were investigated. The test–retest reliability was assessed by Spearman correlation analysis. Cronbach’s α coefficients for internal consistency between total scores and subscores of the test were calculated. Results Areas under the ROC curve in literate and illiterate elderly Moroccans participants corresponded to 0.932 and 0.936, respectively. The cutoff point of 21/22 on the MA-MMSE in literate elderly had the highest sensitivity (85.7%), specificity (94.7%), and a positive likelihood ratio of (16.29%), whereas the cutoff point of 18/19 of the screening test in illiterate elderly yielded the highest sensitivity (92.9%), specificity (95.0%), and a positive likelihood ratio of (18.57%). The Cronbach’s α values of the MA-MMSE for literate and illiterate elderly Moroccans were higher than 0.7. Thirty subjects were randomly selected for participation in the test–retest protocol. Participants were retested after an interval of 4–6 weeks. The test–retest reliability for total scores was significant 0.78 (p < 0.01). Conclusion The findings provide preliminary evidence that the MA-MMSE is a feasible instrument for dementia screening.

Does a linear position transducer placed on a stick and belt provide sufficient validity and reliability of countermovement jump performance outcomes?

Manufacturers recommend that linear position transducers (LPTs) should be placed on the side of a barbell (or wooden dowel) to measure countermovement jump (CMJ) height, but the validity and reliability of this placement have not been compared to other attachment sites. Since this recommended attachment site is far from the centre of mass, a belt attachment where the LPT is placed between the feet may increase the validity and reliability of CMJ data. Thirty-six physical education students participated in the study (24.6 ± 4.3 years; 177.0 ± 7.7 cm; 77.2 ± 9.0 kg). Parameters from the two LPT attachments (barbell and belt) were simultaneously validated to force plate data, where the nature of bias was analysed (systematic vs random). The within-session and between-session reliability of both attachment sites were compared to force plate data using a test-retest protocol of two sets of 5 CMJs separated by 7 days. The LPT provided highly reliable and valid measures of peak force, mean force, mean power, and jump height, where the bias was mostly systematic (r2 > 0.7; ICC > 0.9). Peak velocity, mean velocity, and peak power were in very good agreement with the force plate and were highly reliable (r2 > 0.5; ICC > 0.7). Therefore, both attachment sites produced similar results with a systematic bias compared to force plate data. Thus, both attachment sites seem to be valid for assessing CMJs when the measuring tool and site remain consistent across measurements. However, if LPT data are to be compared to force plate data, recalculation equations should be used.

Test-retest reliability and minimal detectable change for measures of wearable gait analysis system (G-Walk) in children with cerebral palsy.

Cerebral Palsy (CP) is the most frequent cause of physical disability in childhood. CP causes primary deficits such as impairments in muscle tone, muscle weakness, problems in selective motor control and secondary deficits such as contractures and deformities. These deficits lead to motor disorders during movement causing limitations in gait. Sixty percent of children with CP can walk independently despite these problems, however, they present with various gait abnormalities. Gait analysis is used in the quantitative assessment of gait disturbances providing functional diagnosis, assessment for treatment, planning, and monitoring of progress. G-Walk is a wearable sensor device which provides quantitative gait analysis via spatiotemporal parameters and pelvic girdle angles. In literature, there is no study investigating the reliability of the G-Walk in children with CP. The purpose of this study was to confirm the test-retest reliability of a commercially available body-worn sensor 'BTS G-WALK sensor system' for spatiotemporal gait parameters in children with CP. Fifty-four children with CP (mean age: 9.19 ± 3.49 years), Gross Motor Function Classification System (GMFCS) level I-II completed the test-retest protocol with 5 days between tests. The test-retest reliability was calculated using intra-class correlation coefficients (ICC). Minimal detectable changes were calculated using standard error measurements. According to the analysis, ICC varied from 0.799 to 0.977 in all of the gait parameters. The statistical analysis showed that all G-Walk parameters' measurements were found to have almost perfect test-retest reliability. The G-Walk was found to be reliable in gait parameters for children with CP between ages 5 and 15, in GMFCS level I-II. A gait analysis carried out with the G-Walk system is a reliable method to assess gait in children with CP in a clinical setting.

Synergistic effect between quinpirole and L-NAME as well as sulpiride and L-arginine on the modulation of anxiety and memory processes in the 6-OHDA mouse model of Parkinson's disease: An isobologram analysis

We evaluated interactions between dopamine D2 receptor and nitric oxide (NO) actions on the regulation of anxiety and memory in the 6-hydroxydopamine (6-OHDA) mouse model of Parkinson's disease (PD). A unilateral guide cannula was stereotaxically implanted over the right striatum. Elevated plus-maze test (EPM) test–retest protocol was employed to evaluate anxiety and memory in mice. The results revealed that injection of L-NAME (9 mg/kg) induced anxiolytic and amnesic effects, while L-arginine (9 mg/kg) produced anxiogenic and memory-improvement effects in the 6-OHDA mouse model of PD. Administration of sulpiride (20 mg/kg) induced anxiogenic and memory-improvement effects, whereas quinpirole (20 mg/kg) caused anxiolytic and amnesic effects in PD mice. Co-injection of sulpiride (5, 10, and 20 mg/kg) plus L-NAME (3 mg/kg) induced anxiolytic and amnesic effects. Co-injection of sulpiride (20 mg/kg) plus L-arginine (3 mg/kg) induced anxiogenic and memory-improvement effects. Co-administrations of quinpirole (20 mg/kg) and L-NAME (3 mg/kg) induced anxiolytic effect, but co-administration of quinpirole (20 mg/kg) plus L-arginine (3 mg/kg) caused anxiogenic and memory-improvement effects. The isobologram analysis revealed that there is a synergistic effect between sulpiride and L-arginine as well as quinpirole and L-NAME upon induction of anxiogenic and anxiolytic effects, respectively in PD mice. Our results suggested: (1) NO and dopamine D2 receptor mechanisms affect anxiety and memory in PD mice; (2) L-NAME reversed anxiogenic and memory-improvement effect induced by sulpiride; (3) Anxiolytic and amnesic effects induced by quinpirole reversed by L-arginine; (4) There is a synergistic effect between dopamine D2 receptor and NO systems on the modulation of anxiety and memory.

The Med-NKQ: A Reliable Mediterranean Diet Nutrition Knowledge Questionnaire for Cardiovascular Disease

The Mediterranean diet (MD) has significant benefits for cardiovascular disease (CVD), yet clinicians lack reliable tools to measure patient knowledge. This study aimed to develop a short tool to test knowledge of MD related to cardiac health. Themes included foods to reduce CVD risk factors, quantification of servings, and common MD dietary patterns; a maximum score of 42 was determined for correct responses. Content validity was assessed through expert consensus in a Delphi survey. A 70% level of agreement was set for each domain tested. Repeatability was assessed via a test-retest protocol in a sample with self-reported CVD, advertised through social media and administered online. Ten and six of twenty-five invited experts responded to round one and two of the Delphi survey respectively. All items achieved greater than 70% consensus. Twenty people completed the repeatability study. A paired t-test found no significant difference in mean scores between the two test periods (Test one, 28 (standard deviation (SD) 5.4). Test two 29.5, (SD 5.5), p = 0.174) and a Bland-Altman Plot indicated no bias between the two surveys. The Med-NKQ demonstrated good content validity and reliability in people with CVD, and is short and easy to administer, making it practical in clinical and research settings.

Reliability and Validity of the ONAPS Physical Activity Questionnaire in Assessing Physical Activity and Sedentary Behavior in French Adults.

This study was conducted to assess the validity and reliability of a new questionnaire, the ONAPS-PAQ, developed to assess physical activity (PA) and sedentary behaviors (SB) in the general population. A total of 137 healthy adults aged 18 to 69 years were included. Following completion of two physical activity questionnaires (ONAPS-PAQ and GPAQ, the Global physical activity questionnaire) to study concurrent validity, participants wore an accelerometer (UKK-RM42) for 7 days to study criterion validity. A subsample (n = 36) also completed a 7-day-interval test–retest protocol to assess its reliability. Reliability was tested by the intraclass correlation coefficient (ICC) and Kappa coefficient; concurrent and criterion validity by the Spearman correlation coefficient (ρ) and Bland-Altman plot analyses. The ONAPS-PAQ showed good reliability (ICC = 0.71–0.98; Kappa = 0.61–0.99) and concurrent validity (ρ = 0.56–0.86), but only poor criterion validity (ρ = 0.26–0.41), and wide limits of agreement. Self-reported and accelerometer-measured SB were better correlated with ONAPS-PAQ than GPAQ (0.41 vs. 0.26, respectively) and medians were comparable, whereas the GPAQ underestimated SB (SBacc = 481 (432–566), SBONAPS = 480 (360–652), SBGPAQ = 360 (240–540) min·day−1; median (q1-q3)). The ONAPS-PAQ provides good reliability and acceptable validity for the measurement of PA and SB and seems to provide a better assessment of SB than GPAQ.

Validity and Reliability of a Snatch Pull Test to Model the Force-Velocity Relationship in Male Elite Weightlifters.

Sandau, I, Chaabene, H, and Granacher, U. Validity and reliability of a snatch pull test to model the force-velocity relationship in male elite weightlifters. J Strength Cond Res 36(10): 2808-2815, 2022-This study examined the concurrent validity and within-session reliability of parameters describing the force-velocity relationship (FvR) such as maximal force, velocity, power, and the theoretical one repetition maximum snatch performance ( snatchth ) during the snatch pull. The FvR was assessed using the multiple-load (FvR m ) approach and the 2-load (FvR 2 ) approach. Eight male elite weightlifters from the German national team executed the snatch pull in 2 separate experiments. For the concurrent validity assessment (experiment one), during the snatch pull, 7 loads from 70 to 100% were lifted to compute the FvR m , and 2 loads (70 and 100%) were lifted to compute the FvR 2 . For the reliability assessment (experiment 2), a test-retest protocol for the FvR 2 was conducted. Input FvR parameters were determined from video-based barbell tracking. Results indicated no differences (all p > 0.05; all d ≤ 0.07) and extremely large correlations (all r ≥ 0.91) between the FvR m and FvR 2 parameters. The within-session reliability of FvR 2 parameters was excellent (all intraclass correlation coefficient ≥0.97; SEM % ≤1.23%). The percentage smallest real difference (SRD 95 %) of FvR 2 parameters ranged between 1.89 and 3.39%. In summary, using the snatch pull to model FvR 2 parameters is a valid and reliable approach that can easily be integrated into elite weightlifters' daily training routines.

RELIABILITY OF MAKE AND BREAK TESTS IN ASSESSING INTRINSIC FOOT MUSCLE STRENGTH USING A HANDHELD DYNAMOMETER IN HEALTHY YOUNG ADULTS

Purpose: The make and break tests are used in isometric muscle measurement via a handheld dynamometer. This study aimed to compare the reliability of intrinsic foot muscle strength assessment with break and make tests in healthy young adults. Methods: Seventy-five healthy adults completed the test-retest protocol with five days between tests. The maximal isometric strength measure of intrinsic foot muscles was measured during make/break tests using a handheld dynamometer. Test-retest reliability was calculated using intra-class correlation coefficients (ICC). Minimal detectable changes were calculated using standard error measurements. Results: According to the analysis, the strength results of the break test were higher in all muscles when compared to the make test (p&amp;lt;0.05). The strength measurements of the intrinsic foot muscles was found to have almost perfect test-retest reliability in the make and break test (ICC=0.938-0.986). Conclusion: Healthy adults showed stable test-retest results on all muscle strength measurements of the intrinsic foot muscles. The make and break test carried out usnig the handheld dynamometer is a reliable method for assessing intrinsic foot muscle strength in healthy adults. Both make and break tests are reliable measurements for the strength of intrinsic foot muscles.

First-in-Human Assessment of 11C-LSN3172176, an M1 Muscarinic Acetylcholine Receptor PET Radiotracer.

This was a first-in-human study of the PET radiotracer 11C-LSN3172176 for the muscarinic acetylcholine receptor subtype M1. The objectives of the study were to determine the appropriate kinetic model to quantify binding of the tracer to M1 receptors, and the reliability of the chosen quantification method. Methods: Six healthy subjects completed the test-retest protocol, and 5 healthy subjects completed the baseline-scopolamine blocking protocol. Multiple modeling methods were applied to calculate total distribution volume (VT) and nondisplaceable binding potential (BPND) in various brain regions. The reference region was selected from the blocking study. The occupancy plot was applied to compute receptor occupancy by scopolamine and nondisplaceable distribution volume. Results: Tracer uptake was highest in the striatum, followed by neocortical regions and white matter, and lowest in the cerebellum. Regional time-activity curves were fitted well by all models. The 2-tissue-compartment (2TC) model fits were good, but the 2TC parameters often could not be reliably estimated. Because VT correlated well between the 2TC and 1-tissue-compartment (1TC) models after exclusion of unreliable estimates, the 1TC model was chosen as the most appropriate. The cerebellum showed the lowest VT, consistent with preclinical studies showing little to no specific binding in the region. Further, cerebellar VT did not change between baseline and blocking scans, indicating that the cerebellum is a suitable reference region. The simplified reference tissue model (SRTM) slightly underestimated 1TC BPND, and the simplified reference tissue model 2 (SRTM2) improved BPND estimation. An 80-min scan was sufficient to quantify VT and BPND The test-retest study showed excellent absolute test-retest variability for 1TC VT (≤5%) and BPND (≤10%). In the baseline and blocking studies, occupancy values were lower in the striatum than in nonstriatal regions, as may be attributed to differences in regional acetylcholine concentrations. Conclusion: The 1TC and SRTM2 models are appropriate for quantitative analysis of 11C-LSN3172176 imaging data. 11C-LSN3172176 displayed excellent test-retest reproducibility and is a highly promising ligand to quantify M1 receptors in the human brain.

Validation of the Australian version of the Chronic Kidney Disease Self-Management instrument.

The aim of this study is to evaluate the validity and reliability of the modified Chronic Kidney Disease Self-Management instrument in an English-speaking population. There is growing evidence that self-management behaviours can improve outcomes for people with chronic kidney disease. However, there are few suitable instruments available. The study was cross sectional, with a test-retest protocol. Adults with chronic kidney disease attending a primary health care between June and December 2015 completed the Chronic Kidney Disease Self-Management instrument. Construct validity was determined using exploratory factor analysis, internal consistency and test-retest reliability using Cronbach's α and intraclass correlation. For convergent validity, the relationships between knowledge, self-efficacy and self-management were investigated. The Australian version of the Chronic Kidney Disease Self-Management instrument has 17 items grouped into four factors: self-integration, seeking social support, adherence to lifestyle modification and problem solving. The instrument demonstrated good reliability. Self-efficacy was positively correlated with self-management scores, although there was no correlation between chronic kidney disease knowledge and self-management. The Australian version of the Chronic Kidney Disease Self-Management instrument was found to be a valid and reliable patient-reported outcome measure. It can be used in clinical practice to support self-management, as well as future research.

Are There Extended Cognitive Improvements from Different Kinds of Acute Bouts of Physical Activity?

Acute bouts of physical activity of at least moderate intensity have shown to enhance cognition in young as well as older adults. This effect has been observed for different kinds of activities such as aerobic or strength and coordination training. However, only few studies have directly compared these activities regarding their effectiveness. Further, most previous studies have mainly focused on inhibition and have not examined other important core executive functions (i.e., updating, switching) which are essential for our behavior in daily life (e.g., staying focused, resisting temptations, thinking before acting), as well. Therefore, this study aimed to directly compare two kinds of activities, aerobic and coordinative, and examine how they might affect executive functions (i.e., inhibition, updating, and switching) in a test-retest protocol. It is interesting for practical implications, as coordinative exercises, for example, require little space and would be preferable in settings such as an office or a classroom. Furthermore, we designed our experiment in such a way that learning effects were controlled. Then, we tested the influence of acute bouts of physical activity on the executive functioning in both young and older adults (young 16–22 years, old 65–80 years). Overall, we found no differences between aerobic and coordinative activities and, in fact, benefits from physical activities occurred only in the updating tasks in young adults. Additionally, we also showed some learning effects that might influence the results. Thus, it is important to control cognitive tests for learning effects in test-retest studies as well as to analyze effects from physical activity on a construct level of executive functions.

A Reliability and Comparative Analysis of the New Randomized King-Devick Test.

The King-Devick (K-D) test is a rapid visual screening tool that can assess underlying brain trauma such as concussion via impairments in saccadic rhythm. A new tablet version of the K-D test using randomized numbers is now available, but reliability for this new version and comparison to the traditional K-D test has not yet been reported. Known for learning effects in the test, the aim of this study was to determine test-retest reliability and to compare performance of the new "randomized" version to the "traditional" K-D test version. We hypothesized that the "traditional" K-D test would show a greater rate of improvement with repeat application, compared with the "randomized" K-D test. Using a cross-sectional, repeated measures design in a healthy university student cohort (n = 96; age 21.6 ± 2.8 years; 49 women, 47 men), participants were required to complete the K-D test twice with a one-week break between testing sessions. Participants were randomly assigned into a "traditional" group, where they completed a test-retest of the established K-D protocol, using the same numbers; or the "randomized" group, where they completed test-retest protocol using 2 different sets of numbers. Reliability testing showed a strong intraclass correlation coefficient for both the "traditional" test group (control group; 0.95 [CI: 0.91-0.97]) and the "randomized test group" (0.97 [CI: 0.95-0.98]). However, contrary to our hypothesis, no differences were found between "traditional" and "randomized" groups for baseline (control: 42.5 seconds [CI: 40.2-44.9 s] vs randomized: 41.5 [38.7-44.4], P = 0.23) and repeated testing between groups (control: 40.0 seconds [37.9-42.1 s] vs randomized: 39.5 [36.9-42.0], P = 0.55), with both groups showing improved times with repeated testing (control: 2.1 seconds [CI: 1.1-3.2 seconds] and randomized: 1.9 seconds CI: [0.9-2.9 seconds], P < 0.001). The "randomized" version of the K-D test, using different sets of numbers, demonstrates good reliability that is comparable to the traditional K-D testing protocol that uses the same number sets. However, similar to the "traditional" K-D test, learning effects were also observed in the "randomized" test, suggesting that learning effects are not because of content memorization, but rather familiarity of the test. As a result, although either test format is suitable for sideline concussion screening or return to play decisions, comparison of data should be made to the individual's baseline rather than to normative data sets.