Repeated Measures Correlation Research Articles

The Correlation between Carotid Artery Corrected Flow Time and Velocity Time Integral during Central Blood Volume Loss and Resuscitation.

Doppler ultrasound of the common carotid artery is used to infer central hemodynamics. For example, change in the common carotid artery corrected flow time (ccFT) and velocity time integral (VTI) are proposed surrogates of changing stroke volume. However, conflicting data exist which may be due to inadequate beat sample size and measurement variability - both intrinsic to handheld systems. In this brief communication, we determined the correlation between changing ccFT and carotid VTI during progressively severe central blood volume loss and resuscitation. Measurements were obtained through a novel, wireless, wearable Doppler ultrasound system. Sixteen participants (ages of 18-40 years with no previous medical history) were studied across 25 lower body-negative pressure protocols. Relationships were assessed using repeated-measures correlation regression models. In total, 33,110 cardiac cycles comprise this analysis; repeated-measures correlation showed a strong, linear relationship between ccFT and VTI. The strength of the ccFT-VTI relationship was dependent on the number of consecutively averaged cardiac cycles (R1 cycle = 0.70, R2 cycles = 0.74, and R10 cycles = 0.81). These results positively support future clinical investigations employing common carotid artery Doppler as a surrogate for central hemodynamics.

Supraclavicular block evaluation in oncoorthopedic patients under general anesthesia using perfusion index: A prospective cohort study.

Supraclavicular brachial plexus blocks (SCBPB) are routinely placed prior to anaesthetic induction for post-operative pain relief after prolonged orthopaedic oncosurgery, since patients are required to remain awake for sensorimotor evaluation of block. If the window period after surgery but before anesthesia-reversal is employed for administering SCBPB, it bestows the quadruple advantage of being painless, not augmenting surgical bleed, longer post-operative analgesia and reduced opioid-related side effects. The problem spot is assessing SCBPB-efficacy under general anesthesia. This prospective, single-centric, observational cohort study included 30 patients undergoing upper limb orthopaedic oncosurgery under general anesthesia. Perfusion index (PI) was assessed using two separate units of Radical-7™ finger pulse co-oximetry devices simultaneously in both the upper limbs and PI ratios calculated. Skin temperature was noted. After successful block, PI values in blocked limb suddenly increased after 5 min, progressively increasing for next 10 min, whereas PI failed to increase further above that attained post anaesthetic-induction in unblocked limb. PI values in the blocked limb were 4.32, 4.49, 4.95, 7.25, 7.71, 7.90, 7.94, 7.89, and 7.93 at 0, 2, 3, 5, 10, and 15 min post block-institution at reversal and 2 min, 5 min post-reversal, respectively. PI ratios at 2, 3, 5, 10, and 15 min post block-administration in the blocked limb, taking PI at local anaesthetic injection as denominator were 1.04, 1.15, 1.67, 1.78, and 1.83, respectively. Correlation between PI and skin temperature in the blocked limb gave a repeated measures correlation coefficient of 0.79. Monitoring trends in PI and PI-ratio in the blocked limb is a quantitative, non-invasive, inexpensive, simple, effective technique to monitor SCBPB-onset in anaesthetised patients.

Sensitivity, reliability and convergent validity of sequential dual-task measures of listening effort

Objective The aim of the current study was to assess the sensitivity, reliability and convergent validity of objective measures of listening effort collected in a sequential dual-task. Design On each trial, participants viewed a set of digits and listened to a spoken sentence presented at one of a range of signal-to-noise ratios (SNR) and then typed the sentence-final word and recalled the digits. Listening effort measures included word response time, digit recall accuracy and digit response time. In Experiment 1, SNR on each trial was randomised. In Experiment 2, SNR varied in a blocked design, and in each block self-reported listening effort was also collected. Study samples Separate groups of 40 young adults participated in each experiment. Results Effects of SNR were observed for all measures. Linear effects of SNR were generally observed even with word recognition accuracy factored out of the models. Among the objective measures, reliability was excellent, and repeated-measures correlations, though not between-subjects correlations, were nearly all significant. Conclusion The objective measures assessed appear to be sensitive and reliable indices of listening effort that are non-redundant with speech intelligibility and have strong within-participants convergent validity. Results support use of these measures in future studies of listening effort.

Frequency of HTLV-1 seroconversion between pregnancies in Nagasaki, Japan, 2011-2018.

Human T-cell leukemia virus type-1 (HTLV-1) is transmitted vertically from an infected mother to her child via breastfeeding during infancy or horizontally via sexual contact. However, little information is available on the HTLV-1 seroconversion rate in pregnant mothers and the impact of new HTLV-1 infection on mothers and babies during the perinatal period. From the database of a prefecture-wide antenatal adult T-cell leukemia prevention program in Nagasaki, Japan, we extracted data on 57,323 pregnant women who were screened for anti-HTLV-1 antibody during 2011-2018. Data on the 16,863 subjects whose HTLV-1 proviral load (PVL) was measured more than twice were included in our analyses. In total, 133 (0.79%) pregnant women were HTLV-1-positive during their first pregnancy and nine (0.05%) seroconverted before or during subsequent pregnancies (between pregnancies). The median PVL (per 100 peripheral blood mononuclear cells) was significantly lower in the seroconverted mothers (0.10%) than in the initially seropositive mothers (0.15%). A repeated measures correlation analysis for the individual PVLs of the HTLV-1-positive pregnant women showed that PVL increased with parity number (rrm = 0.25) with no perinatal problems. The HTLV-1 seroconversion rate between pregnancies was 0.05%, and their HTLV-1 PVL increased annually but no perinatal problems were noted.

Impedance change during intentional weight loss in Thai obese patients

<h2>Summary</h2><h3>Background & aims</h3> Longitudinal measurements of raw bioelectrical impedance analysis (BIA) parameters suggested a worsening of the nutritional status in obese patients during weight loss after bariatric surgery. The effects of weight reduction through dietary intervention on raw BIA parameters is rarely described. <h3>Methods</h3> A retrospective observational study was conducted on obese patients who were in a weight-loss program. Dietary counseling, exercise, and lifestyle modification were suggested as the main approach to lose weight. Then longitudinal follow-up visits were scheduled every 1–3 months for up to 2 years. On each visit, body weight, waist, and hip circumferences were recorded along with BIA measurements. Repeated measures correlation (r_rm) was used to assess the relationship between BIA-derived impedance and body weight. <h3>Results</h3> A total of 116 obese patients were recruited. Participants had lost their weight from 113.47 ± 26.73 kg at the first visit to 103.69 ± 23.97 kg at the last visit (<i>P</i> < 0.001). A significant decrease of percentage of body fat was observed by −3.30 ± 4.33% from baseline. Total body water and fat-free mass were also significantly decreased. There was an increase in impedance from 483.55 ± 78.38 ohm at baseline to 496.11 ± 82.30 ohm at the last visit (<i>P</i> < 0.001). The r_rm between impedance and body weight was −0.31 (95% CI −0.37 to −0.25, <i>P</i> < 0.001). <h3>Conclusions</h3> Impedance had a significant negative correlation on body weight in obese patients during intentional weight loss, which might be due to decreased total body water and fat-free mass. Further study is required to explore the clinical meaning of these changes.

Comparing tibial accelerations between delivery and follow-through foot strikes in cricket pace bowling

ABSTRACT Foot strikes of the pace-bowling delivery stride produce large ground reaction forces, which may be linked to injury, yet the biomechanics of the follow-through are unknown. This study assessed tibial accelerations across the delivery and follow-through foot strikes in pace bowlers and evaluated relationships between these measures and five common pace-bowling intensity metrics. Fifteen sub-elite male pace bowlers performed deliveries at warm-up, match, and maximal intensities. Tibial accelerations were measured using tibial-mounted inertial measurement units and recorded at back- and front-foot initial and re-contacts. A trunk-worn global navigation satellite system unit measured PlayerLoad™, run-up speed, and distance. Ball speed and perceived exertion measures were also recorded. A linear mixed model showed statistical significance of prescribed intensities (p < .001) and foot strike for tibial acceleration (p < .001). Tibial accelerations showed positive increases with changes in prescribed intensity (p < .05). The greatest magnitude of tibial acceleration was found at back foot re-contact (mean ± SD; 1139 ± 319 m/s2). Repeated-measures correlations of tibial acceleration between foot contacts were weak (r = 0.2–0.4). The greatest magnitude of tibial acceleration reported at back foot re-contact may have implications for injury incidence, representing an important avenue for future pace bowling research.

Validity of Ultra-Short-Term HRV Analysis Using PPG-A Preliminary Study.

Continuous measurement of heart rate variability (HRV) in the short and ultra-short-term using wearable devices allows monitoring of physiological status and prevention of diseases. This study aims to evaluate the agreement of HRV features between a commercial device (Bora Band, Biosency) measuring photoplethysmography (PPG) and reference electrocardiography (ECG) and to assess the validity of ultra-short-term HRV as a surrogate for short-term HRV features. PPG and ECG recordings were acquired from 5 healthy subjects over 18 nights in total. HRV features include time-domain, frequency-domain, nonlinear, and visibility graph features and are extracted from 5 min 30 s and 1 min 30 s duration PPG recordings. The extracted features are compared with reference features of 5 min 30 s duration ECG recordings using repeated-measures correlation, Bland–Altman plots with 95% limits of agreements, Cliff’s delta, and an equivalence test. Results showed agreement between PPG recordings and ECG reference recordings for 37 out of 48 HRV features in short-term durations. Sixteen of the forty-eight HRV features were valid and retained very strong correlations, negligible to small bias, with statistical equivalence in the ultra-short recordings (1 min 30 s). The current study concludes that the Bora Band provides valid and reliable measurement of HRV features in short and ultra-short duration recordings.

Effects of three-dimension movie visual fatigue on cognitive performance and brain activity.

To further develop three-dimensional (3D) applications, it is important to elucidate the negative effects of 3D applications on the human body and mind. Thus, this study investigated differences in the effects of visual fatigue on cognition and brain activity using visual and auditory tasks induced by watching a 1-h movie in two dimensions (2D) and 3D. Eighteen young men participated in this study. Two conditions were randomly performed for each participant on different days, namely, watching the 1-h movie on television in 2D (control condition) and 3D (3D condition). Before and after watching the 1-h movie on television, critical flicker fusion frequency (CFF: an index of visual fatigue), and response accuracy and reaction time for the cognitive tasks were determined. Brain activity during the cognitive tasks was evaluated using a multi-channel near-infrared spectroscopy system. In contrast to the control condition, the decreased CFF, and the lengthened reaction time and the decreased activity around the right primary somatosensory cortex during Go/NoGo blocks in the visual task at post-viewing in the 3D condition were significant, with significant repeated measures correlations among them. Meanwhile, in the auditory task, the changes in cognitive performance and brain activity during the Go/NoGo blocks were not significant in the 3D condition. These results suggest that the failure or delay in the transmission of visual information to the primary somatosensory cortex due to visual fatigue induced by watching a 3D movie reduced the brain activity around the primary somatosensory cortex, resulting in poor cognitive performance for the visual task. This suggests that performing tasks that require visual information, such as running in the dark or driving a car, immediately after using a 3D application, may create unexpected risks in our lives. Thus, the findings of this study will help outlining precautions for the use of 3D applications.

Minutes Played Should be Used for the Calculation of Session Rating of Perceived Exertion During Matches in NCAA Division I Women’s Soccer

Introduction: Monitoring Training Load in soccer is used to achieve the best individualized performance outcomes and to prevent injuries. However, there is no clear recommendation for which ‘match duration’ should be used in the calculation of match Session Rating of Perceived Exertion Training Load (sRPE-TL) in NCAA DI women’s soccer. Therefore, the purpose of this study was to establish a duration standard to be used in the calculation of sRPE-TL in collegiate NCAA DI women’s soccer matches. A secondary aim was to investigate whether multiple positions require the use of different durations for the calculation of sRPE-TL. Methods: Seventeen athletes (means ± standard deviations: age 20 ± 1.1 yrs., height 170 ± 6.6 cm, weight 64.6 ± 7.0 kg) participated in this study. Repeated measures correlations were used to determine the relationship between the different sRPE-TL calculations and objective variables (e.g., GPS variables and HR-based variable). Data was analyzed using the rmcorr package in R Studio executing R. Alpha was set a-priori at p ≤ 0.05. Results: The s-RPE-TL using the four ‘minutes played’ durations (‘minutes played only’, ‘warm-up added’, ‘halftime added’, and ‘warm-up and halftime added’) were strongly correlated with TLS (r = .773, .776, .789, .786), total distance (r = .825, .813, .811, .798), number of sprints (r = .716, .717, .712, .711), HSD (r = .608, .615, .609, .612), and mechanical load (r = .738, .738, .734, .732). When separated by positions, the correlations between sRPE-TL and objective data were similar across all four ‘minutes played’ durations. Conclusions: Any of the ‘minutes played’ durations should be used to calculate match sRPE-TL values for the entire team. Multiple positions do not require the use of different durations for the calculation of sRPE-TL which facilitates sRPE-TL comparisons across positions.

Responsiveness of UMSARS and other clinical measures in a longitudinal structured care clinic for multiple system atrophy.

As understanding of multiple system atrophy (MSA) pathophysiology improves, clinical trials of disease-modifying therapies are starting. Outcome measures responsive to disease progression will be critical, but the United MSA Rating Scale (UMSARS) has limitations. The MSA multidisciplinary clinic at the University of Texas Southwestern is a longitudinal clinic with structured assessments performed at fixed time intervals. The objective of this study was to evaluate the performance of clinical measures in assessing MSA progression over time. Data from 73 subjects with clinically diagnosed MSA were analyzed using repeated measures correlation models. Observations were made every 4months, with up to 3years of data included for each patient. UMSARS-I and UMSARS-II correlated positively with the MSA Quality of Life (QOL) scale. The rate of change was 3.12points per year (ppy) for UMSARS-I and 5.55ppy for UMSARS-II. Some individual UMSARS questions contributed more significantly than others to overall UMSARS rate of change. Based on this finding, and using repeated measures correlations between question combinations and QOL, an optimization of UMSARS parts I and II was curated. The amended UMSARS-I included 8 of the 12 subquestions, and the amended UMSARS-II included 10 of the 14 subquestions. Data from a longitudinal MSA clinic allows better characterization of the performance of UMSARS as a clinical outcome measure. A curated set of UMSARS questions appears more responsive to change and accounts for correlation with QOL, and could be the starting point for an improved MSA outcome measure.

A global epidemiological analysis of COVID-19 vaccine types and clinical outcomes

ObjectivesTo compare messenger RNA (mRNA)–based and adenovirus-vectored vaccines (ADVVs) with inactivated virus vaccines (IVVs) using real-world aggregate data. MethodsWe performed longitudinal analyses of publicly accessible epidemiological, clinical, virological, vaccine-related, and other public health data from 41 eligible countries during the first half of 2021. The relationships between vaccination coverage and clinical outcomes were analyzed using repeated measures correlation analyses and mixed-effects modeling to adjust for potential mediating and confounding factors. ResultsCountries that used mRNA and/or ADVV (n = 31) vs IVV, among other vaccine types (n = 10), had different distributions of age (42.4 vs 33.9 years, respectively; P-value = 0.0006), gross domestic product per capita ($ 38,606 vs $ 20,422, respectively; P <0.0001), and population sizes (8,655,541 vs 5,139,162, respectively; P-value = 0.36). After adjustment for country differences, the stringency of nonpharmaceutical interventions, and dominant SARS-CoV-2 variant types, populations that received mRNA and/or ADVV had significantly lower rates of cases and deaths over time (P <0.001 for each analysis). Populations vaccinated with IVV, among others, had significantly higher rates of cases and deaths over time (P <0.05 for each analysis). ConclusionThe real-world effectiveness of IVV may be inferior to mRNA and/or ADVV, and prospective comparative studies are needed to critically evaluate the role of IVV in the context of contemporary SARS-CoV-2 variants.

Implications of the choice of distance-based measures in assessing and investigating tumble turn performance.

Although the tumble turn in swimming has been studied extensively, no consensus exists about which measure is best suited to capture its performance. The aim of this study was to better understand the implications of choosing a particular distance-based performance measure for assessing and investigating tumble turn performance in freestyle swimming. To this end, a large set of retrospective turn data consisting of 2,813 turns performed by 160 swimmers was analyzed statistically in three steps. First, a mixed-effects model was derived for the entire data set, which showed that both performance level and sex had clear effects on the distance-based performance measures and performance determining variables studied in the literature. Second, repeated measures correlations were calculated for the entire data set and four performance level- and sex-based subgroups to determine the level of association between the performance measures. This analysis revealed that the performance measures were strongly correlated (r > 0.84 and p < 0.05 for all possible pairs), largely independent of performance level and sex. This finding implies that the choice of performance measure is not very critical when one is interested solely in the overall performance. In the third and last step, mixed-effects models were derived for the performance measures of interest to establish the importance of different turn-related actions for each measure, again for both the entire data set and the four subgroups separately. The results of this analysis revealed that performance measures with short(er) distances are more sensitive to changes in the adaptation time and reflect the wall contact time better than performance measures with long(er) distances, which in contrast are more useful if the focus is on the approach speed prior to the turn. In this final analysis, various effects of performance level and sex were found on the technical execution of the tumble turn.

Utilizing Countermovement Jumps As A Measure Of Match Preparedness In NCAA Division I Women’s Soccer

PURPOSE: Training load quantification and monitoring is used in collegiate athletics to help coaches and supporting staff to determine whether players are prepared for upcoming matches. The purpose of this study was to assess the within-subjects correlation of matchday countermovement jump (CMJ) height and the 7-day sum of training load variables preceding matchday in NCAA Division I women’s soccer athletes. The authors hypothesized that matchday CMJ height would show negative moderate correlations with the 7-day sum of training load variables. METHODS: A total of 23 female soccer players (20 ± 1.1 years; 1.70 ± 0.07 m; 64.6 ± 7.0 kg) participated in this study. Data from seven matches from the 2020 season were included in this analysis. Repeated measures correlations (rmcorr) were used to determine the within-subjects correlations of matchday CMJ height and total distance covered (TD), training load score (TLS; using training impulse [TRIMP] calculations), number of sprints, and distanced covered at high-speed (< 9.32 mph; HODO). Alpha was set a priori at p ≤ 0.05 and the data was analyzed using R Studio (version 1.4.1106, R Studio, Boston, MA, USA) executing R (version 4.0.4, University of California, Berkeley, CA, USA). RESULTS: The correlations between training load variables and matchday CMJ height were not statistically significant (p > 0.05). The matchday CMJ height showed very weak nonsignificant relationships with TD (r = -0.071, p = 0.450, 95% CI = -0.254, 0.116), TLS (r = -0.016, p = 0.874, 95% CI = -0.191, 0.223), number of sprints (r = -0.116, p = 0.218, 95% CI = -0.296, 0.071), and HODO (r = -0.011, p = 0.904, 95% CI = -0.175, 0.197). CONCLUSIONS: The results suggest that the CMJ height may not be a good indicator of matchday preparedness in collegiate Division I women’s soccer as it did not correlate with the 7-day sum of training load variables preceding matchday. Future research should aim to address other strategies to assess matchday preparedness in collegiate women’s soccer in order to enhance training periodization to better prepare the athletes for competition.

Assessing Responsiveness of the Trapeziometacarpal Arthrosis Symptoms and Disability Questionnaire.

This study aimed to assess the responsiveness of the Trapeziometacarpal Arthrosis Symptoms and Disability (TASD) questionnaire after corticosteroid injections and operative management for trapeziometacarpal osteoarthritis (TMC-OA). This longitudinal cohort study included patients with TMC-OA who underwent treatment (corticosteroid injection or surgery). Measurements occurred at baseline and follow-up time points: 6 weeks, 3 months, 6 months, and 1 year. Patient measures were collected electronically using a data repository platform. The TASD is a validated psychometric patient-administered scale. We examined responsiveness by correlating the TASD scores with another known effective indicator of change (shortened Disabilities of the Arm, Shoulder, and Hand [QuickDASH]). Repeated score measurements over time were analyzed using analysis of variance, and correlations between questionnaires were reported with repeated measures correlation and Pearson correlation coefficients. The nonsurgical cohort undergoing corticosteroid injections included 31 (66%) women and 16 (34%) men, and the surgical cohort included 29 (71%) women and 12 (29%) men. Both the QuickDASH and the TASD captured a statistically significant improvement in symptom burden postoperatively (P < .0001 for both questionnaires), whereas no statistical significance was noted after corticosteroid injections (P = .45 and P = .34, respectively). There was a strong correlation between QuickDASH and TASD questionnaires (r = 0.87, P < .0001). The TASD is a promising TMC-OA-specific questionnaire to capture responsiveness following treatment, particularly following surgery. The responsiveness of TASD was demonstrated in the TMC-OA cohort. Further research is needed to define a minimal clinically important difference.

Inter-limb Asymmetries, Power, And Internal Training Loads In NCAA Division I Female Soccer Athletes

Periodic testing and workload monitoring throughout a competitive season can help athletes and coaches periodize training to optimize performance. In particular, vertical jump testing to assess power output and inter-limb asymmetries can be used to monitor athlete-readiness. PURPOSE: To evaluate the relationship between internal training loads, power output, and inter-limb asymmetries throughout a competitive soccer season. METHODS: National Collegiate Athletic Association (NCAA) Division I female soccer players (N = 21) were evaluated at all practices and games using a team-based heart rate monitoring system to assess internal training load via Banister’s training impulse score (TRIMP). At the beginning of each week, athletes performed a dynamic warmup followed by maximal bilateral (CMJ) and single leg (SL) countermovement vertical jump tests using a hands-on-hips method assessed via a digital contact mat. The best of two trials were used for each jump test. An asymmetry index (ASY) was calculated by dividing dominant by non-dominant SL height. Linear mixed effects models were used to assess changes in TRIMP, CMJ, and ASY throughout the season. Repeated measures correlations were used to determine relationships between weekly changes in TRIMP, CMJ and ASY using an absolute ASY score. Significance was set at p < 0.05. Descriptive statistics are presented as mean ± standard deviation. RESULTS: Time main effects were observed for weekly changes in TRIMP (573 ± 150au; p < 0.001) and CMJ (43.1 ± 0.8 cm; p = 0.01) over the season. No changes in ASY were observed (2.0 ± 1.5%; p = 0.09). There was a significant weak correlation between CMJ and ASY (r = 0.17; p = 0.04), but no other relationships between TRIMP, CMJ, and ASY were observed (p > 0.05). CONCLUSIONS: Changes in internal workload and power output were apparent throughout the season. Although no significant changes in ASY were seen, an inverse correlation between ASY and power output was observed, which may impact on-field performance. Declines in peak power along with higher asymmetry rates have been associated with increased injury risk. Proper athlete management programs that incorporate systematic monitoring and periodic testing may help to mitigate these risks by affording the opportunity for early interventions designed to improve athlete readiness.

Agreement Between Single- And Double-point Estimations Of Pulse Wave Velocity

Aortic pulse wave velocity (PWV) is a common measure of large artery stiffness, and an independent predictor of cardiovascular disease risk. Currently, the gold standard PWV measure, carotid-femoral pulse wave velocity (cfPWV), is taken using two arterial sites. A single-point method of PWV would be useful as it would decrease required operator training and patient burden. PURPOSE: To assess (1) overall, and (2) repeated measures (RM) agreement, between cfPWV and two test measures, which estimate aortic PWV from the brachial artery. METHODS: The criterion cfPWV measure was obtained with carotid and femoral artery oscillometric cuffs. Brachial-based PWV was obtained using the BP+ device (PWVBP) and the Mobil-o-graph device (PWVMOG). Measurements were made in the supine, then semi-recumbent, then seated position. Postural change was used as a hemodynamic perturbation for ascertainment of RM agreement. Multi-level correlation was used to calculate overall agreement (independent of posture), and RM correlation was used to determine whether change (i.e., with change in posture) in the test measure agrees with change in the criterion. Strength of agreement was interpreted as the intraclass correlation coefficient (ICC), with estimates of <0.2, 0.2, 0.4, 0.7, and 0.9 representing negligible, weak, moderate, strong, and very strong agreement, respectively. RESULTS: Complete data was collected for 30 subjects (age: 24 ± 5.5 years, 57% female). cfPWV increased approximately 1m/s from the supine to semi-recumbent, and from the semi-recumbent to seated posture. The overall and RM agreements between PWVMOG and cfPWV were weak, with the ICC: 0.35, 95%CI [0.15, 0.52] and ICC -0.28, 95% CI [-0.50, -0.02], respectively. The overall agreement between PWVBP and cfPWV was moderate (ICC 0.50, 95% CI [0.32, 0.64]) and the RM agreement was weak (ICC 0.30, 95% CI [0.05, 0.52]). Limits of agreement plots indicated bias, with both single-point methods producing lower PWV than the criterion. CONCLUSIONS: The results show PWVMOG weakly but significantly agreed with cfPWV, whereas PWVBP moderately and significantly agreed with cfPWV. RM agreement was weak, likely because both single point-measures changed minimally with postural change, whereas the criterion device recorded expected increases in PWV with more upright posture.

Examining the Concurrent and Predictive Validity of Single Items in Ecological Momentary Assessments.

Although single items can save time and burden in psychology research, concerns about their reliability have made the use of multiple-item measures the default standard practice. Although single items cannot demonstrate internal reliability, their criterion validity can be compared with multiple-item measures. Using ecological momentary assessment data, we evaluated repeated measures correlations and constructed multilevel cross-lagged models to assess concurrent and predictive validity of single- and multiple-item measures. Correlations between the single- and multiple-item measures ranged from .24 to .61. In 27 of 29 unique single-item predictor models, single items demonstrated significant predictive validity, and in one of eight sets of comparisons, a single-item predictor exhibited a larger effect size than its multiple-item counterpart. Although multiple-item measures generally performed better than single items, the added benefit of multiple items was modest in most cases. The present data provide support for the use of single-item measures in intensive longitudinal designs.

Are Measurement Instruments Responsive to Assess Acute Responses to Load in High-Level Youth Soccer Players?

PurposeThe aim of this study was to assess the short-term responsiveness of measurement instruments aiming at quantifying the acute psycho-physiological response to load in high-level adolescent soccer players.MethodsData were collected from 16 high-level male youth soccer players from the Under 15 age group. Players were assessed on two occasions during the week: after 2 days of load accumulation (“high load”) and after at least 48 h of rest. Measurements consisted of the Short Recovery and Stress Scale (SRSS), a countermovement jump (CMJ) and a sub-maximal run to assess exercise heart-rate (HRex) and heart-rate recovery (HRR60s). Training load was quantified using total distance and high-speed running distance to express external and sRPE training load to express internal load. It was expected that good instruments can distinguish reliably between high load and rest.ResultsOdd ratios (0.74–1.73) of rating one unit higher or lower were very low for athlete-reported ratings of stress and recovery of the SRSS. Standardized mean high load vs. rest differences for CMJ parameters were trivial to small (−0.31 to 0.34). The degree of evidence against the null hypothesis that changes are interchangeable ranged from p = 0.04 to p = 0.83. Moderate changes were observed for HRex (−0.62; 90% Cl −0.78 to −0.47; p = 3.24 × 10−9), while small changes were evident for HRR60s (0.45; 90% Cl 0.08–0.80; p = 0.04). Only small to moderate repeated-measures correlations were found between the accumulation of load and acute responses across all measurement instruments. The strongest relationships were observed between HRex and total distance (rm-r = −0.48; 90% Cl −0.76 to −0.25).ConclusionResults suggest that most of the investigated measurement instruments to assess acute psycho-physiological responses in adolescent soccer players have limited short-term responsiveness. This questions their potential usefulness to detect meaningful changes and manage subsequent training load and program adequate recovery.

Longitudinal trimodal imaging of midbrain-associated network degeneration in Parkinson’s disease

The prevailing network perspective of Parkinson’s disease (PD) emerges not least from the ascending neuropathology traceable in histological studies. However, whether longitudinal in vivo correlates of network degeneration in PD can be observed remains unresolved. Here, we applied a trimodal imaging protocol combining 18F-fluorodeoxyglucose (FDG)- and 18F-fluoro-L-Dopa- (FDOPA)-PET with resting-state functional MRI to assess longitudinal changes in midbrain metabolism, striatal dopamine depletion and striatocortical dysconnectivity in 17 well-characterized PD patients. Whole-brain (un)paired-t-tests with focus on midbrain or striatum were performed between visits and in relation to 14 healthy controls (HC) in PET modalities. Resulting clusters of FDOPA-PET comparisons provided volumes for seed-based functional connectivity (FC) analyses between visits and in relation to HC. FDG metabolism in the left midbrain decreased compared to baseline along with caudatal FDOPA-uptake. This caudate cluster exhibited a longitudinal FC decrease to sensorimotor and frontal areas. Compared to healthy subjects, dopamine-depleted putamina indicated stronger decline in striatocortical FC at follow-up with respect to baseline. Increasing nigrostriatal deficits and striatocortical decoupling were associated with deterioration in motor scores between visits in repeated-measures correlations. In summary, our results demonstrate the feasibility of in-vivo tracking of progressive network degeneration using a multimodal imaging approach. Specifically, our data suggest advancing striatal and widespread striatocortical dysfunction via an anterior-posterior gradient originating from a hypometabolic midbrain cluster within a well-characterized and only mild to moderately affected PD cohort during a relatively short period.

Longitudinal Correlations Between Intravoxel Incoherent Motion (IVIM) and Dynamic Contrast-Enhanced (DCE) MRI During Radiotherapy in Prostate Cancer Patients.

PurposeIntravoxel incoherent motion (IVIM) is a promising technique that can acquire perfusion information without the use of contrast agent, contrary to the more established dynamic contrast-enhanced (DCE) technique. This is of interest for treatment response monitoring, where patients can be imaged on each treatment fraction. In this study, longitudinal correlations between IVIM- and DCE parameters were assessed in prostate cancer patients receiving radiation treatment.Materials and Methods20 prostate cancer patients were treated on a 1.5 T MR-linac with 20 x 3 or 3.1 Gy. Weekly IVIM and DCE scans were acquired. Tumors, the peripheral zone (PZ), and the transition zone (TZ) were delineated on a T2-weighted scan acquired on the first fraction. IVIM and DCE scans were registered to this scan and the delineations were propagated. Median values from these delineations were used for further analysis. The IVIM parameters D, f, D* and the product fD* were calculated. The Tofts model was used to calculate the DCE parameters Ktrans, kep and ve. Pearson correlations were calculated for the IVIM and DCE parameters on values from the first fraction for each region of interest (ROI). For longitudinal analysis, the repeated measures correlation coefficient was used to determine correlations between IVIM and DCE parameters in each ROI.ResultsWhen averaging over patients, an increase during treatment in all IVIM and DCE parameters was observed in all ROIs, except for D in the PZ and TZ. No significant Pearson correlations were found between any pair of IVIM and DCE parameters measured on the first fraction. Significant but low longitudinal correlations were found for some combinations of IVIM and DCE parameters in the PZ and TZ, while no significant longitudinal correlations were found in the tumor. Notably in the TZ, for both f and fD*, significant longitudinal correlations with all DCE parameters were found.ConclusionsThe increase in IVIM- and DCE parameters when averaging over patients indicates a measurable response to radiation treatment with both techniques. Although low, significant longitudinal correlations were found which suggests that IVIM could potentially be used as an alternative to DCE for treatment response monitoring.