Category: Statistics

Br J Math Stat Psychol. 2021 Nov 6. doi: 10.1111/bmsp.12257. Online ahead of print.

ABSTRACT

Approximately counting and sampling knowledge states from a knowledge space is a problem that is of interest for both applied and theoretical reasons. However, many knowledge spaces used in practice are far too large for standard statistical counting and estimation techniques to be useful. Thus, in this work we use an alternative technique for counting and sampling knowledge states from a knowledge space. This technique is based on a procedure variously known as subset simulation, the Holmes-Diaconis-Ross method, or multilevel splitting. We make extensive use of Markov chain Monte Carlo methods and, in particular, Gibbs sampling, and we analyse and test the accuracy of our results in numerical experiments.

PMID:34741466 | DOI:10.1111/bmsp.12257

J Cachexia Sarcopenia Muscle. 2021 Nov 6. doi: 10.1002/jcsm.12847. Online ahead of print.

ABSTRACT

BACKGROUND: Body weight scales to height with a power of ≈2 (weight/height² ), forming the basis of body mass index (BMI). The corresponding scaling of body composition measured by abdominal computed tomography (CT) to height has not been established. The objective of this analysis was to quantify the scaling of body composition measured by a single-slice axial abdominal CT image (skeletal muscle, and visceral, subcutaneous, and total adipose tissue) to height in patients with colorectal cancer (CRC).

METHODS: This cross-sectional study included non-Hispanic white males and females, aged 18-80 years, who were diagnosed with stage I-III CRC at an integrated health care system in North America between January 2006 and December 2011. Body composition was measured by a single-slice axial CT image of the third lumbar vertebra and analysed with a semi-automated threshold segmentation procedure. Allometric regression models were used to quantify height scaling powers (β ± standard error) for each body composition measure, adjusted for age, for males and females. An interaction test was used to determine if height scaling powers were statistically significantly different between males and females.

RESULTS: Among 2036 subjects, the mean (standard deviation) age was 64 ± 11 years, 1008 (49.5%) were female, and the mean (standard deviation) BMI was 27.9 ± 5.4 kg/m² . Powers for skeletal muscle area were 1.06 ± 0.12 for males and 0.80 ± 0.12 for females (P = 0.049). Powers for visceral adipose tissue area were 1.81 ± 0.64 for males and 0.57 ± 0.79 for females (P = 0.16). Powers for subcutaneous adipose tissue area were 2.04 ± 0.42 for males and 0.81 ± 0.45 for females (P = 0.056). Powers for total abdominal adipose tissue area were 1.80 ± 0.46 for males and 0.76 ± 0.50 for females (P = 0.20).

CONCLUSIONS: Body composition measured by single-slice axial abdominal CT, particularly muscle area, scales to height with age-adjusted powers that are different than 2 and are distinct between males and females. These observations may have implications for the development of height-adjusted body composition indices in patients with cancer.

PMID:34741439 | DOI:10.1002/jcsm.12847

Anat Rec (Hoboken). 2021 Nov 6. doi: 10.1002/ar.24825. Online ahead of print.

ABSTRACT

Cribra orbitalia is a phenomenon with interdisciplinary interest. However, the etiology of cribra orbitalia remains unclear. Recently, the appearance of cribra orbitalia was identified as vascular in nature. This study assessed the relationship between anatomical variation of vasculature, as determined by the presence of meningo-orbital foramina, and the presence of cribra orbitalia in 178 orbits. Cribra orbitalia was identified in 27.5% (49:178) of orbits (22.7%, 35:154 adult orbits and 58.3%, 14:24 subadult orbits) and meningo-orbital foramina were identified in 65.8% (100:152) of orbits. Among the 150 total intact adult orbits (i.e., orbital roof and posterior orbits both intact), cribra orbitalia was found in 35 (23.3%). Of these 35 occurrences of cribra orbitalia, 32 (91.4%) had the concurrent finding of a meningo-orbital foramen. However, in the absence of the meningo-orbital foramen, cribra orbitalia was only found in three sides out of the total sample of intact orbits (3:150; 2.0%). Fisher’s exact test revealed that the presence of cribra orbitalia and the meningo-orbital foramen were statistically dependent variables (p=0.0002). Visual evidence corroborated statistical findings- vascular impressions joined cribra orbitalia to meningo-orbital foramina. This study identifies that individuals who possess a meningo-orbital foramen are anatomically predisposed to developing cribra orbitalia. Conversely, cribra orbitalia is unlikely to occur in an individual who does not possess a meningo-orbital foramen. Thus, the antecedent of cribra orbitalia is both vascular and developmental in nature. This report represents an important advancement in the understanding of cribra orbitalia- there is an anatomical predisposition to the development of cribra orbitalia.

PMID:34741429 | DOI:10.1002/ar.24825

Autism Res. 2021 Nov 6. doi: 10.1002/aur.2633. Online ahead of print.

ABSTRACT

Commercially available wearable biosensors have the potential to enhance psychophysiology research and digital health technologies for autism by enabling stress or arousal monitoring in naturalistic settings. However, such monitors may not be comfortable for children with autism due to sensory sensitivities. To determine the feasibility of wearable technology in children with autism age 8-12 years, we first selected six consumer-grade wireless cardiovascular monitors and tested them during rest and movement conditions in 23 typically developing adults. Subsequently, the best performing monitors (based on data quality robustness statistics), Polar and Mio Fuse, were evaluated in 32 children with autism and 23 typically developing children during a 2-h session, including rest and mild stress-inducing tasks. Cardiovascular data were recorded simultaneously across monitors using custom software. We administered the Comfort Rating Scales to children. Although the Polar monitor was less comfortable for children with autism than typically developing children, absolute scores demonstrated that, on average, all children found each monitor comfortable. For most children, data from the Mio Fuse (96%-100%) and Polar (83%-96%) passed quality thresholds of data robustness. Moreover, in the stress relative to rest condition, heart rate increased for the Polar, F(1,53) = 135.70, p < 0.001, ηp² = 0.78, and Mio Fuse, F(1,53) = 71.98, p < 0.001, ηp² = 0.61, respectively, and heart rate variability decreased for the Polar, F(1,53) = 13.41, p = 0.001, ηp² = 0.26, and Mio Fuse, F(1,53) = 8.89, p = 0.005, ηp² = 0.16, respectively. This feasibility study suggests that select consumer-grade wearable cardiovascular monitors can be used with children with autism and may be a promising means for tracking physiological stress or arousal responses in community settings. LAY SUMMARY: Commercially available heart rate trackers have the potential to advance stress research with individuals with autism. Due to sensory sensitivities common in autism, their comfort wearing such trackers is vital to gathering robust and valid data. After assessing six trackers with typically developing adults, we tested the best trackers (based on data quality) in typically developing children and children with autism and found that two of them met criteria for comfort, robustness, and validity.

PMID:34741438 | DOI:10.1002/aur.2633

J Nurs Scholarsh. 2021 Nov 5. doi: 10.1111/jnu.12712. Online ahead of print.

ABSTRACT

PURPOSE: To synthesize results from multiple studies to determine the effects of music interventions on chronic pain in older adults.

DESIGN: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline to identify and select studies.

METHODS: Relevant studies were identified from nine electronic databases. The Joanna Briggs Institute (JBI) critical appraisal checklists were employed to assess methodological quality. All authors performed screening, data extraction, and synthesis. Inclusion criteria were clinical trials investigating music for chronic pain in older adults aged 65 and older.

FINDINGS: Eight studies involving 524 older adults were included, comprising five randomized controlled trials and three quasi-experimental studies. Music interventions consisted of live music, recorded music, and active music, with a variety of music styles and genres. Despite the small and short-term effects, five studies presented significantly positive outcomes for reducing chronic pain and its common comorbidities in older adults following music interventions. Three studies reported decreased trends in pain scores although they did not reach statistical significance.

CONCLUSIONS: Music has potential to be an effective adjuvant for managing chronic pain in older adults.

CLINICAL RELEVANCE: Nurses can incorporate music into the care of older adults with chronic pain.

PMID:34741407 | DOI:10.1111/jnu.12712

Acad Emerg Med. 2021 Nov 5. doi: 10.1111/acem.14412. Online ahead of print.

ABSTRACT

BACKGROUND: Emergency Department (ED) visits are known to be anxiety-ridden and stress-provoking experiences especially in the pediatric population. Distraction techniques have been used as a means to reduce anxiety and stress thereby facilitating care in the ED and making the visit less unpleasant. Our study aimed to evaluate the effectiveness of an active and immersive distraction technique, using a mindfulness-based virtual reality (VR) program (Take-Pause), to alleviate anxiety in pediatric ED patients.

METHODS: A prospective, randomized, single-blinded study, evaluating ED patients aged 13-17 years with a chief complaint of acute pain was conducted. Patients were randomized to either the active distraction intervention (VR group), utilizing the VR headset for 5 minutes; or to the passive distraction intervention (iPad group), playing on an iPad for 5 minutes. The primary outcome was a difference in the change in anxiety scores on the Spielberger State-Trait Anxiety Inventory between the two groups. Secondary outcomes included a difference in pain scores, respiratory rate (RR) and heart rate (HR) between the groups.

RESULTS: A total of 110 subjects were enrolled. At 15 minutes, the mean anxiety score for the VR group improved by 10 points vs. 6 points in the iPad group (P<.001; 95% CI: .44 to 7.6). There was no statistical significance in the reduction of pain scores (p=.953) and RR’s (p= .776) between the groups. Patients enrolled in both groups did not experience any adverse effects.

CONCLUSION: Take-Pause, offering an active and immersive distraction technique, is more effective than a passive distraction approach to lower anxiety levels in adolescent ED patients.

PMID:34741370 | DOI:10.1111/acem.14412

J Nurs Scholarsh. 2021 Nov 5. doi: 10.1111/jnu.12715. Online ahead of print.

ABSTRACT

PURPOSE: This study examined the combined role psychological capital and social capital play in the severity of second victim syndrome experienced by registered nurses.

DESIGN: This research study was an ex post facto, cross-sectional, non-experimental survey design. Data were collected from October to December 2018. The study sample was composed of 1167 nurses recruited through 12 professional nursing associations in the United States.

METHODS: Self-report questionnaires were administered to measure psychological capital (Psychological Capital Questionnaire), social capital (Social Capital Outcomes for Nurses) and second victim syndrome (Second Victim Experience and Support Tool). Data cleaning and analysis of 1167 cases were conducted via SPSS v25 and structural equation modeling of 999 cases was conducted with AMOS v25.

FINDINGS: The SEM analysis demonstrated that psychological capital, on its own, had no effect on the severity of the second victim experience. Social capital, on its own, had a statistically significant relationship with second victim severity. The combined impact of social capital and psychological capital had a statistically significant effect on second victim severity.

CONCLUSIONS: The results of this study have practical implications that include unit-based peer support programs and an increased focus on supportive workplace cultures. Programmatic efforts should also focus on social capital at the team level as well as the importance of building self-efficacy through increasing mastery experiences, modeling of behavior, social persuasion and monitoring one’s physiological responses.

CLINICAL RELEVANCE: These findings demonstrate the importance of social capital to mitigation of second victim experiences, while also demonstrating that psychological capital has no effect on second victim severity. Building social capital and collective efficacy are critical to mitigation of second victim syndrome.

PMID:34741394 | DOI:10.1111/jnu.12715

Med Phys. 2021 Nov 6. doi: 10.1002/mp.15325. Online ahead of print.

ABSTRACT

PURPOSE: Gadolinium-based contrast agents (GBCAs) may add value to Magnetic Resonance (MR)-only radiotherapy workflows including on hybrid machines such as the MR Linac. The impact of GBCAs on radiotherapy dose distributions however have not been well studied. This work used retrospective GBCA-enhanced datasets to assess the dosimetric effect of GBCAs on head and neck plans.

METHODS: Ten patients with oropharyngeal SCC receiving radiotherapy from November 2018-April 2020 were included in this study. Radiotherapy planning included contrast-enhanced CT and MR scans. A contrast agent ‘contour’ was defined by delineating GBCA-enhanced regions using an agreed window/level threshold, transferred to the planning CT and given a standardised electron density (ED) of 1.149 in the Monaco treatment planning system (Elekta AB). Four plans were per patient calculated and compared using two methods: (1) optimised without contrast (Plan A) then recalculated with ED (Plan B), and (2) optimised with contrast ED (Plan C) then without (Plan D). For target parameters minimum and maximum doses to 1cc of PTVs, D₉₅ values, and percent dose differences were calculated. Dose differences for OARs were calculated as a percentage of the clinical tolerance value. For the purposes of this study, ±2% over the whole treatment course was considered to be a clinically acceptable dose deviation. Wilcoxon-signed rank tests were used to determine any dose differences within and between the two methods of optimisation and recalculation (p < 0.05). Pearson’s correlations were used to establish the relationship between gadolinium uptake volume in a structure (i.e. proportion of structure covered by a density override) and the resulting dose difference.

RESULTS: The median percent dose differences for key reportable dosimetric parameters between non-contrast and simulated contrast plans were <1.2% over all fractions over all patients for reportable target parameters (mean 0.34%, range 0.22-1.02%). The percent dose differences for max dose to 1cc of both PTV1 and PTV2 were significantly different after application of density override (p < 0.05) but only in method 2 (Plan C vs Plan D). For D₉₅ PTV1 there was a statistically significant effect of density override (p < 0.01), however only in method 1 (Plan A vs Plan B). There were no significant differences between calculation methods of the impact of contrast in most target parameters with the exception of D₉₅ PTV1 (p < 0.01), and for D₉₅ PTV2 (p < 0.05). The median percent dose differences for reportable OAR parameters as a percentage of clinical planning tolerances were <2.0% over a full treatment course (mean 0.65%, range 0.27-1.62%). There were no significant differences in dose to OARs within or between methods for contrast impact assessment.

CONCLUSIONS: Dose differences to targets and OARs in oropharyngeal cancer treatment due to a presence of GBCA were minimal and this work suggests that prospective in vivo evaluations of impact may not be necessary in this clinical site. Accounting for GBCAs may not be needed in daily adaptive workflows on the MR Linac. This article is protected by copyright. All rights reserved.

PMID:34741308 | DOI:10.1002/mp.15325

J Sleep Res. 2021 Nov 6:e13512. doi: 10.1111/jsr.13512. Online ahead of print.

ABSTRACT

Previous work has shown that both long and short sleep duration is associated with increased mortality, with lowest risk around 7 hr. This has had widespread impact on views on the optimal sleep duration. However, age, being employed/retired, and blue-/white-collar status, may influence the time available for sleep and thus, confound the association. We investigated the role of these factors on the association between sleep duration and mortality. We used employed and retired participants (N = 25,430) from the Swedish National March Cohort and Cox proportional hazards regression to model the shape of the association. We found a significant U-shaped association in a multivariable model with a hazard ratio (HR) of 1.24 (95% confidence interval [CI] 1.10, 1.39) for <5-hr sleep duration, and a HR of 1.30 (95% CI 1.12, 1.51) for ≥9-hr sleep duration, with the lowest HR for 7 hr, but with a span of low HRs from 5 to 8 hr. Unadjusted values showed a pronounced U-shape. Adjusting for age accounted for most of the attenuation in the multivariable model. Stratification into five age groups showed a significant U-shape only in those aged >60.3 years at baseline. The shape of the association did not differ between blue-/white-collar workers, nor between employed and retired groups. We conclude that the U-shaped association between sleep duration and mortality is present only in older individuals.

PMID:34741361 | DOI:10.1111/jsr.13512

Brain Imaging Behav. 2021 Nov 5. doi: 10.1007/s11682-021-00562-0. Online ahead of print.

ABSTRACT

The locus coeruleus is the main noradrenergic nucleus of the brain and is often affected in neurodegenerative diseases. Recently, magnetic resonance imaging with specific T1-weighted sequences for neuromelanin has been used to evaluate locus coeruleus integrity in patients with these conditions. In some of these studies, abnormalities in locus coeruleus signal have also been found in healthy controls and related to ageing. However, this would be at variance with recent post-mortem studies showing that the nucleus is not affected during normal ageing. The present study aimed at evaluating locus coeruleus features in a well-defined cohort of cognitively healthy subjects who remained cognitively intact on a one-year follow-up. An ad-hoc semiautomatic analysis of locus coeruleus magnetic resonance was applied. Sixty-two cognitively intact subjects aged 60-80 years, without significant comorbidities, underwent 3 T magnetic resonance with specific sequences for locus coeruleus. A semi-automatic tool was used to estimate the number of voxels belonging to locus coeruleus and its intensity was obtained for each subject. Each subject underwent extensive neuropsychological testing at baseline and 12 months after magnetic resonance scan. Based on neuropsychological testing 53 subjects were cognitively normal at baseline and follow up. No significant age-related differences in locus coeruleus parameters were found in this cohort. In line with recent post-mortem studies, our in vivo study confirms that locus coeruleus magnetic resonance features are not statistically significantly affected by age between 60 and 80 years, the age range usually evaluated in studies on neurodegenerative diseases. A significant alteration of locus coeruleus features in a cognitively intact elderly subject might be an early sign of pathology.

PMID:34741273 | DOI:10.1007/s11682-021-00562-0