Validity of the Wrist-Worn Polar Vantage V2 to Measure Heart Rate and Heart Rate Variability at Rest

Heart rate (HR) and heart rate variability (HRV) can be monitored with wearable devices throughout the day. Resting HRV in particular, reflecting cardiac parasympathetic activity, has been proposed to be a useful marker in the monitoring of health and recovery from training. This study examined the validity of the wrist-based photoplethysmography (PPG) method to measure HR and HRV at rest. Recreationally endurance-trained participants recorded pulse-to-pulse (PP) and RR intervals simultaneously with a PPG-based watch and reference heart rate sensor (HRS) at a laboratory in a supine position (n = 39; 5-min recording) and at home during sleep (n = 29; 4-h recording). In addition, analyses were performed from pooled laboratory data (n = 11340 PP and RR intervals). Differences and correlations were analyzed between the HRS- and PPG-derived HR and LnRMSSD (the natural logarithm of the root mean square of successive differences). A very good agreement was found between pooled PP and RR intervals with a mean bias of 0.17 ms and a correlation coefficient of 0.993 (p < 0.001). In the laboratory, HR did not differ between the devices (mean bias 0.0 bpm), but PPG slightly underestimated the nocturnal recordings (bias −0.7 bpm, p < 0.001). PPG overestimated LnRMSSD both in the laboratory (bias 0.20 ms, p < 0.001) and nocturnal recordings (bias 0.17 ms, p < 0.001). However, very strong intraclass correlations in the nocturnal recordings were found between the devices (HR: 0.998, p < 0.001; LnRMSSD: 0.931, p < 0.001). In conclusion, PPG was able to measure HR and HRV with adequate accuracy in recreational athletes. However, when strict absolute values are of importance, systematic overestimation, which seemed to especially concern participants with low LnRMSSD, should be acknowledged.

The Validity and Reliability of Two Commercially Available Load Sensors for Clinical Strength Assessment

Objective: Handheld dynamometers are common tools for assessing/monitoring muscular strength and endurance. Health/fitness Bluetooth load sensors may provide a cost-effective alternative; however, research is needed to evaluate the validity and reliability of such devices. This study assessed the validity and reliability of two commercially available Bluetooth load sensors (Activ5 by Activbody and Progressor by Tindeq). Methods: Four tests were conducted on each device: stepped loading, stress relaxation, simulated exercise, and hysteresis. Each test type was repeated three times using the Instron ElectroPuls mechanical testing device (a gold-standard system). Test–retest reliability was assessed through intraclass correlations. Agreement with the gold standard was assessed with Pearson’s correlation, interclass correlation, and Lin’s concordance correlation. Results: The Activ5 and Progressor had excellent test–retest reliability across all four tests (ICC(3,1) ≥ 0.999, all p ≤ 0.001). Agreement with the gold standard was excellent for both the Activ5 (ρ ≥ 0.998, ICC(3,1) ≥ 0.971, ρc ≥ 0.971, all p’s ≤ 0.001) and Progressor (ρ ≥ 0.999, ICC(3,1) ≥ 0.999, ρc ≥ 0.999, all p’s ≤ 0.001). Measurement error increased for both devices as applied load increased. Conclusion: Excellent test–retest reliability was found, suggesting that both devices can be used in a clinical setting to measure patient progress over time; however, the Activ5 consistently had poorer agreement with the gold standard (particularly at higher loads).

Frailty and Processing Speed Performance at the Cusp of Midlife in CATSLife

Frailty is an important multi-domain measure of health status and aging. Processing speed (PS) performance may be predictive of later frailty among older adults, but the interrelation between frailty and PS at the cusp of mid-adulthood is unclear. Using data from the ongoing Colorado Adoption/Twin Study of Lifespan Behavioral Development and Cognitive Aging (CATSLife; N = 1213; Mean age = 33.22 years; SD = 5.0), we constructed a 24-item frailty sum score across anthropomorphic, objective health, and perceived health and engagement measures based on the Accumulation of Deficits model. PS was measured using the Colorado Perceptual Speed (CPS) and WAIS-III Digit Symbol (DS) tests. All mixed-effects regression models accounted for clustering among siblings, and covariates included sex, age, race, ethnicity, and educational attainment. Intraclass correlations (ICCs) [95% CI] for frailty among siblings, adjusted for sex and age, ranged from near zero for siblings in adoptive families, .13 [.08-.30] for nonadoptive siblings/fraternal (DZ) twins, and .44 [.40-.48] for identical (MZ) twins, suggesting possible heritable influences. Poorer PS performance was associated with higher frailty, but was significant for DS only (B: DS = -0.43, p =.005). Furthermore, the DS-frailty association was magnified by age (B: DSxAge = -0.06, p =.025), suggesting that the associations between processing speed and frailty may increase with age. These findings help elucidate the interrelationship between indicators of frailty and cognitive performance for adults approaching midlife, a salient and understudied period within lifespan development.

Test–Retest Reliability and Reliable Change Estimates for Four Mobile Cognitive Tests Administered Virtually in Community-Dwelling Adults

Objective: Remote mobile cognitive testing (MCT) is an expanding area of research, but psychometric data supporting these measures are limited. We provide preliminary data on test–retest reliability and reliable change estimates in four MCTs from SWAY Medical, Inc.Methods: Fifty-five adults from the U.S. Midwest completed the MCTs remotely on their personal mobile devices once per week for 3 consecutive weeks, while being supervised with a video-based virtual connection. The cognitive assessment measured simple reaction time (“Reaction Time”), go/no-go response inhibition (“Impulse Control”), timed visual processing (“Inspection Time”), and working memory (“Working Memory”). For each cognitive test except Working Memory, we analyzed both millisecond (ms) responses and an overall SWAY composite score.Results: The mean age of the sample was 26.69years (SD=9.89; range=18–58). Of the 55 adults, 38 (69.1%) were women and 49 (89.1%) used an iPhone. Friedman’s ANOVAs examining differences across testing sessions were nonsignificant (ps&gt;0.31). Intraclass correlations for Weeks 1–3 were: Reaction Time (ms): 0.83, Reaction Time (SWAY): 0.83, Impulse Control (ms): 0.68, Impulse Control (SWAY): 0.80, Inspection Time (ms): 0.75, Inspection Time (SWAY): 0.75, and Working Memory (SWAY): 0.88. Intraclass correlations for Weeks 1–2 were: Reaction Time (ms): 0.75, Reaction Time (SWAY): 0.74, Impulse Control (ms): 0.60, Impulse Control (SWAY): 0.76, Inspection Time (ms): 0.79, Inspection Time (SWAY): 0.79, and Working Memory (SWAY): 0.83. Natural distributions of difference scores were calculated and reliable change estimates are presented for 70, 80, and 90% CIs.Conclusion: Test–retest reliability was adequate or better for the MCTs in this virtual remote testing study. Reliable change estimates allow for the determination of whether a particular level of improvement or decline in performance is within the range of probable measurement error. Additional reliability and validity data are needed in other age groups.

A semi-automatic approach for longitudinal 3D upper airway analysis using voxel based registration

Objectives: To propose and validate a reliable semi-automatic approach for three-dimensional (3D) analysis of the upper airway (UA) based on voxel-based registration (VBR). Methods: Post-operative cone beam computed tomography (CBCT) scans of ten orthognathic surgery patients were superimposed to the pre-operative CBCT scans by VBR using the anterior cranial base as reference. Anatomic landmarks were used to automatically cut the UA and calculate volumes and cross-sectional areas (CSA). The 3D analysis was performed by two observers twice, at an interval of two weeks. Intraclass correlations and Bland-Altman plots were used to quantify the measurement error and reliability of the method. The relative Dahlberg error was calculated and compared with a similar method based on landmark re-identification and manual measurements. Results: Intraclass correlation coefficient (ICC) showed excellent intra- and inter observer reliability (ICC ≥0.995). Bland-Altman plots showed good observer agreement, low bias and no systematic errors. The relative Dahlberg error ranged between 0.51–4.30% for volume and 0.24–2.90% for CSA. This was lower when compared with a similar, manual method. Voxel-based registration introduced 0.05–1.44% method error. Conclusions: The proposed method is shown to have excellent reliability and high observer agreement. The method is feasible for longitudinal clinical trials on large cohorts due to being semi-automatic.

Test-retest reliability for common tasks in vision science

Research in perception and attention has typically sought to evaluate cognitive mechanisms according to the average response to a manipulation. Recently, there has been a shift toward appreciating the value of individual differences and the insight gained by exploring the impacts of between-participant variation on human cognition. However, a recent study suggests that many robust, well-established cognitive control tasks suffer from surprisingly low levels of test-retest reliability (Hedge et al., 2018b). We tested a large sample of undergraduate students (n = 160) in two sessions (separated by 1–3 weeks) on four commonly used tasks in vision science. We implemented measures that spanned the range of visual processing, including motion coherence (MoCo), useful field of view (UFOV), multiple-object tracking (MOT), and visual working memory (VWM). Intraclass correlations ranged from excellent to poor suggesting that some task measures are more suitable for assessing individual differences than others. VWM capacity (ICC = 0.89), MoCo threshold (ICC = 0.60), UFOV middle accuracy (ICC = 0.60) and UFOV outer accuracy (ICC = 0.74) showed good-to-excellent reliability. Other measures, namely the maximum number of items tracked in MOT (ICC = 0.41) and UFOV number accuracy (ICC = 0.48), showed moderate reliability; the MOT threshold (ICC = 0.36) and UFOV inner accuracy (ICC = 0.30) showed poor reliability. In this paper, we present these results alongside a summary of reliabilities estimated previously for other vision science tasks. We then offer useful recommendations for evaluating test-retest reliability when considering a task for use in evaluating individual differences.

Development of a novel brief quantitative sensory testing protocol that integrates static and dynamic pain assessments: Test-retest performance in healthy adults

Objective Quantitative sensory testing is an expanding pain research domain with numerous clinical and research applications. There is a recognized need for brief reliable quantitative sensory testing protocols that enhance assessment feasibility. This study aimed to integrate static (pain threshold, tolerance, suprathreshold) and dynamic (conditioned pain modulation, offset analgesia, temporal summation) pain reactivity measures into a brief 20-minute protocol that uses a single portable device. The test-retest performance of this optimized protocol was evaluated. Design Using a test-retest design, the brief quantitative sensory testing assessment was administered to participants on two occasions separated by exactly 7 days. Setting A clinical psychology research laboratory at Syracuse University. Subjects Participants were 33 healthy adults recruited from Syracuse University’s online research participation pool. Methods A portable computerized quantitative sensory testing device delivered contact-heat pain to assess static and dynamic pain measures in participants. Dynamic responses were continuously recorded using a computerized visual analog scale. Results Pain threshold, tolerance, and suprathreshold exhibited excellent reliability (intraclass correlations ranged from 0.80 to 0.83). Conditioned pain modulation, offset analgesia, temporal summation yielded reliability in the good to excellent range (intraclass correlations ranged from 0.66 to 0.71). Conclusions Findings suggested that this brief integrated QST protocol may reliably monitor human pain reactivity over brief periods. This protocol may enhance quantitative sensory testing feasibility in clinical and research settings.

P145 Assessing the Performance of Automatic Analysis During Routine Intralab Conordance Activities

Introduction This study aims to retrospectively assess the performance of somnolyzer against trained scientist performance of PSG analysis, under routine interlab concordance conditions in an Australian laboratory. Methods Retrospective study (2016 – 2018). Study data included 200 epoc fragments with SWS, REM and NREM. PSG data sets (n = 36) consisted of type 1 (n = 31) and type 2 (n = 5) studies. Individual scorers were compared to a master scoreset set by consensus from two experienced sleep scientists. The automatic analysis system used was Somnolyzer 24x7. Data analysis involved; Group 1: intraclass correlations and Bland-Altman plots, Group 2: Paired T-tests. Results Human analysis was shown to outperform automatic analysis in each major metric assessed, except sleep latency. Automatic analysis performed to a similar level in 6 out of 9 of the major metrics assessed (r &gt; 0.9), however the 95% limit of agreement range was found to larger. Automatically analysed RDI’s were more likely to be lower than the master score sets, as were arousal indices. Conclusions These findings support using caution with automatic analysis, particularly with medical interpretation and practice. Automatic analysis performance can vary dramatically between PSG data sets. This output can vary from one that is comparable to a human analysis through to a level that is well below that of human scorers, under concordance conditions. Consideration should be given to the accuracy of automatic analysis when making scientific conclusions with borderline cases.

Ligaments of the scapho-trapezial-trapezoidal joint: MR anatomy in asymptomatic and symptomatic individuals

Purpose To evaluate the MRI anatomy of the scapho-trapezial-trapezoidal (STT) ligament complex in asymptomatic and symptomatic individuals. Material and methods In this retrospective study, STT ligament complex of 42 (male 69%, median age 37.5 years) asymptomatic (n = 25) and symptomatic (n = 17) (defined as pain described over the STT joint) individuals was examined using a high-resolution 3D proton density-weighted isovoxel sequence (MR arthrogram) with multiplanar reconstructions. Two musculoskeletal radiologists independently assessed visibility, signal intensity (SI), morphology, and thickness of the radiopalmar scapho-trapezial ligament (rpSTL), palmar scapho-capitate capsular ligament (pSCL), palmar STT capsule (pSTTC), and dorsal STT capsule (dSTTC). Results Interreader agreement ranged from fair to good and intraclass correlations were good. The rpSTL was almost always visible (85.7%/80.1%; reader 1/reader 2). The pSCL and dSTTC were visible in all cases. The pSTTC was visible in only 52.4%/42.9%. Mean thickness of the rpSTL, pSCL, pSTTC, and dSTTC was 1.4 ± 0.5 mm/1.3 ± 0.5 mm, 2.8 ± 0.7 mm/2.7 ± 0.6 mm, 0.5 ± 0.5 mm/0.4 ± 0.4 mm, and 0.5 ± 0.3 mm/0.3 ± 0.3 mm. Both readers rated SI of the rpSTL significantly more often as increased in the symptomatic group (increased SI in asymptomatic group: 20%/15%; symptomatic group: 56%/50%) (p-values < 0.005). For all other ligaments, no significant difference was observed for SI between symptomatic and asymptomatic group (p-values ranging between 0.188 and 0.890). For all other ligaments, no significant differences were observed regarding ligament visibility, morphology, and thickness (p-values ranging between 0.274 and 1.000). Conclusion The anatomy of the STT ligament complex can consistently be visualized on high-resolution 3D MRI. Increased signal intensity of rpSTL is significantly more frequent in patients with radial-sided wrist pain.

Inter-rater reliability of subthreshold psychotic symptoms in individuals with 22q11.2 deletion syndrome

Background Pathways leading to psychosis in 22q11.2 deletion syndrome (22q11.2DS) have been the focus of intensive research during the last two decades. One of the common clinical risk factors for the evolution of psychosis in 22q11.2DS is the presence of positive and negative subthreshold psychotic symptoms. The gold standard for measuring subthreshold symptoms is the Structured Interview for Prodromal Syndromes (SIPS) and its accompanying Scale of Prodromal Symptoms (SOPS) ratings. Although the scale has been used by many centers studying 22q11.2DS, the inter-site reliability of the scale in this population has never been established. Methods In the present study, experienced clinical assessors from three large international centers studying 22q11.2DS independently rated video recordings of 18 adolescents and young adults with 22q11.2DS. Results The intraclass correlations coefficients (ICCs) among three raters for the SOPS total scores, as well as for the positive, negative, and disorganization subscale scores, were good-to-excellent (ICCs range 0.73–0.93). The raters were also able to reliably determine the subjects’ subthreshold syndrome status (ICC = 0.71). The reliability of individual items was good-to-excellent for all items, ranging from 0.61 for motor disturbances [G3] to 0.95 for bizarre thinking. Conclusions Our results show that trained clinicians can reliably screen for subthreshold psychotic symptoms in individuals with 22q11.2DS. To increase assessment reliability, we suggest specific clarifications and simplifications to the standard SIPS interview for future studies.