Category: Statistics

Aging Cell. 2021 Oct 27:e13497. doi: 10.1111/acel.13497. Online ahead of print.

ABSTRACT

The study of parental lifespan has emerged as an innovative tool to advance aging biology and our understanding of the genetic architecture of human longevity and aging-associated diseases. Here, we leveraged summary statistics of a genome-wide association study including over one million parental lifespans to identify genetically regulated genes from the Genotype-Tissue Expression project. Through a combination of multi-tissue transcriptome-wide association analyses and genetic colocalization, we identified novel genes that may be associated with parental lifespan. Mendelian randomization (MR) analyses also identified circulating proteins and metabolites causally associated with parental lifespan and chronic diseases offering new drug repositioning opportunities such as those targeting apolipoprotein-B-containing lipoproteins. Liver expression of HP, the gene encoding haptoglobin, and plasma haptoglobin levels were causally linked with parental lifespan. Phenome-wide MR analyses were used to map genetically regulated genes, proteins and metabolites with other human traits as well as the disease-related phenome in the FinnGen cohorts (n = 135,638). Altogether, this study identified new candidate genes, circulating proteins and metabolites that may influence human aging as well as potential therapeutic targets for chronic diseases that warrant further investigation.

PMID:34704651 | DOI:10.1111/acel.13497

J Magn Reson Imaging. 2021 Oct 27. doi: 10.1002/jmri.27976. Online ahead of print.

ABSTRACT

BACKGROUND: Although studies have described factors associated with failed magnetic resonance elastography (MRE), little is known about what factors influence usable elastography data.

PURPOSE: To identify factors that have a negative impact on percent measurable liver volume (pMLV), defined as the proportion of usable liver elastography data relative to the volume of imaged liver in patients undergoing MRE.

STUDY TYPE: Retrospective.

SUBJECTS: A total of 264 patients (n = 132 males, n = 132 females; mean age = 57 years) with suspected or known chronic liver disease underwent MRE paired with a liver protocol MRI.

FIELD STRENGTH/SEQUENCE: MRE was performed on a single 1.5 T scanner using a two-dimensional gradient-recalled echo phase-contrast sequence with a passive acoustic driver overlying the right hemiliver.

ASSESSMENT: Stiffness maps (usable data at 95% confidence) and liver contours on magnitude images of the MRE acquisition were manually traced and used to assess mean stiffness and pMLV. Hepatic fat fraction and R² * values were also calculated. The distance from the acoustic wave generator on the skin surface to the liver edge was measured. Two radiologists performed the MR analyses with 50 overlapping cases for inter-reader analysis.

STATISTICAL TESTS: Linear regression was performed to identify factors significantly associated with pMLV. Intraclass correlation was performed for inter-reader reliability.

RESULTS: pMLV was 31% ± 20% (range 0%-86%). Complete MRE failure (i.e. pMLV = 0%) occurred in 10 patients (4%). Multivariate linear regression identified higher hepatic fat fraction, R² *, BMI, and driver-to-liver surface distance; male sex; and lower mean liver stiffness was significantly independently associated with lower pMLV. Intraclass correlation for pMLV was 0.96, suggestive of excellent reliability.

DATA CONCLUSION: Higher fat fraction, R² *, BMI, driver-to-liver surface distance, male sex, and lower mean liver stiffness were associated with lower pMLV. Optimization of image acquisition parameters and driver placement may improve MRE quality, and pMLV likely serves as a diagnostic utility quality control metric.

LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2.

PMID:34704644 | DOI:10.1002/jmri.27976

Mol Ecol. 2021 Oct 27. doi: 10.1111/mec.16247. Online ahead of print.

ABSTRACT

Understanding selection’s impact on the genome is a major theme in biology. Functionally-neutral genetic regions can be affected indirectly by natural selection, via their statistical association with genes under direct selection. The genomic extent of such indirect selection, particularly across loci not physically linked to those under direct selection, remains poorly understood, as does the time scale at which indirect selection occurs. Here we use field experiments and genomic data in stick insects, deer mice and stickleback fish to show that widespread statistical associations with genes known to affect fitness cause many genetic loci across the genome to be impacted indirectly by selection. This includes regions physically distant from those directly under selection. Then, focusing on the stick insect system, we show that statistical associations between SNPs and other unknown, causal variants result in additional indirect selection in general and specifically within genomic regions of physically linked loci. This widespread indirect selection necessarily makes aspects of evolution more predictable. Thus, natural selection combines with chance genetic associations to affect genome-wide evolution across linked and unlinked loci and even in modest-sized populations. This process has implications for the application of evolutionary principles in basic and applied science.

PMID:34704650 | DOI:10.1111/mec.16247

J Magn Reson Imaging. 2021 Oct 27. doi: 10.1002/jmri.27972. Online ahead of print.

ABSTRACT

BACKGROUND: A novel application of cine Displacement ENcoding with Stimulated Echoes Magnetic Resonance Imaging (DENSE MRI) has recently been described to assess regional heterogeneities in circumferential strain around the aortic wall in vivo; however, validation is first required for successful clinical translation.

PURPOSE: To validate the quantification of regional circumferential strain around the wall of an aortic phantom using DENSE MRI.

STUDY TYPE: In vitro phantom study.

POPULATION: Three polyvinyl alcohol aortic phantoms with eight axially oriented nitinol wires embedded evenly around the walls.

FIELD STRENGTH/SEQUENCE: 3 T; gradient-echo aortic DENSE MRI with spiral cine readout, gradient-echo phase-contrast MRI (PCMR) with Cartesian cine readout.

ASSESSMENT: Phantoms were connected to a pulsatile flow loop and peak DENSE-derived regional circumferential Green strains at 16 equally spaced sectors around the wall were assessed according to previously published algorithms. “True” regional circumferential strains were calculated by manually tracking displacements of the nitinol wires by two independent observers. Normalized circumferential strains (NCS) were calculated by dividing regional strains by the mean strain. Finally, DENSE-derived regional strain was corrected by multiplying regional DENSE NCS by the mean strain calculated from the diameter change on the PCMR.

STATISTICAL TESTS: One-sample t-test, Paired-sample t-test, and analysis of variance with Bonferroni correction, coefficient of variation (CoV), Bland-Altman analysis; P < 0.05 was considered statistically significant.

RESULTS: Aortic DENSE MRI significantly overestimated circumferential strain compared to the wire-tracking method (mean difference and SD 0.030 ± 0.014, CoV 0.31). However, NCS demonstrated good agreement between DENSE and wire-tracking data (mean difference 0.000 ± 0.172, CoV 0.15). After correcting the DENSE-derived regional strain, the mean difference in regional circumferential strain between DENSE and wire-tracking was significantly reduced to 0.006 ± 0.008, and the CoV was reduced to 0.18.

DATA CONCLUSION: For aortic phantoms with mild spatial heterogeneity in circumferential strain, the previously published aortic DENSE MRI technique successfully assessed the regional NCS distribution but overestimated the mean strain. This overestimation is correctable by computing a more accurate mean circumferential strain using a separate cine scan.

LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 2.

PMID:34704637 | DOI:10.1002/jmri.27972

J Nurs Manag. 2021 Oct 26. doi: 10.1111/jonm.13499. Online ahead of print.

ABSTRACT

AIM: To explore the relationships among self-efficacy, information literacy, social support and career success of clinical nurses, and identify factors influencing clinical nurses’ career success in northwestern China.

BACKGROUND: Understanding the influencing factors of career success is important for the professional development of nurses and the improvement of clinical nursing quality. Many influencing factors of career success have been identified, but there is no large-scale research on the relationships among self-efficacy, information literacy, social support and career success of clinical nurses based on Kaleidoscope Career Model. Studies examining the association of the four factors remain limited.

METHODS: A total of 3,011 clinical nurses from 30 hospitals in northwestern China were selected in the cross sectional survey and the response rate was 94.71%. The clinical nurses completed the online self-report questionnaires including self-efficacy, information literacy, social support rating scale and career success scale. The data were analyzed by SPSS23.0 statistical software using t-test, analysis of variance, Pearson’s correlation and multiple linear regression. Structural Equation Model (SEM) was used to analyze the influencing factors of career success using Mplus 8.3.

RESULTS: The career success of clinical nurses in northwestern China was at a medium level. The linear multivariate regression analysis showed that self-efficacy (β=0.513), social support (β=0.230), information support (β=0.106), information consciousness (β=-0.097), information knowledge (β=0.067), information ethics (β=-0.053), hospital grade (β=0.118), marital status (β=-0.071) and age (β=-0.037) entered regression equation of clinical nurses’ career success (all P< 0.05). SEM results showed that the career success was negatively correlated with demographic characteristics, and positively correlated with social support and self-efficacy.

CONCLUSION: Demographic characteristics, self-efficacy, social support and information literacy are the influencing factors of nurses’ career success which should be considered in the process of promoting nurses’ career success.

IMPLICATIONS FOR NURSING MANAGEMENT: Nursing managers need to acknowledge the significance of nurses’ career success both for the realization of their own value and for the improvement of clinical nursing quality. They should encourage nurses to enhance self-efficacy and render more social support through incentive policies, and foster nurses’ information literacy through information technology training so as to improve their career success.

PMID:34704641 | DOI:10.1111/jonm.13499

Kardiol Pol. 2021 Oct 27. doi: 10.33963/KP.a2021.0142. Online ahead of print.

ABSTRACT

BACKGROUND: There is a need to develop patient classification methods to adjust post-discharge care, improving survival after ST-segment elevation myocardial infarction (STEMI).

AIMS: The study aimed to determine whether a neural network (NN) is better than logistic regression (LR) in mortality prediction in STEMI patients.

MATERIAL AND METHODS: The study included patients from the Polish Registry of Acute Coronary Syndromes (PL-ACS). Patients with the first anterior STEMI treated with the primary percutaneous coronary intervention (pPCI) of the left anterior descending (LAD) artery between 2009 and 2015 and discharged alive were included in the study. Patients were randomly divided into three groups: learning (60%), validation (20%), and test group (20%). Two models (LR and NN) were developed to predict 6-month all-cause mortality. The predictive values of LR and NN were evaluated with the Area Under the Receiver Operating Characteristics Curve (AUROC), and the comparison of AUROC for learning and test groups was performed. Validation of both methods was performed in the same group.

RESULTS: Out of 175,895 patients with acute coronary syndrome, 17 793 were included in the study. The all-cause 6-month mortality was 5.9%. Both NN and LR had good predictive values. Better results were obtained in the NN approach regarding the models’ statistical quality – AUROC 0.8422 vs 0.8137 for LR (P <0.0001). AUROC in the test groups were 0.8103 and 0.7939, respectively (P = 0.037).

CONCLUSIONS: The neural network may have a better predictive value than logistic regression in patients after the first STEMI.

PMID:34704605 | DOI:10.33963/KP.a2021.0142

Laryngoscope. 2021 Oct 27. doi: 10.1002/lary.29922. Online ahead of print.

ABSTRACT

OBJECTIVES/HYPOTHESIS: To determine the impact of vestibular schwannoma (VS) position relative to the internal auditory canal (IAC) on postoperative facial nerve function and extent of surgical resection.

STUDY DESIGN: Retrospective chart review.

METHODS: Retrospective review of patients undergoing resection of large (≥25 mm) VSs. Outcome measures included early (≤1 month) facial function, long-term (≥1 year) facial function and extent of resection. Tumor measurements included the greatest dimension, dimension anterior to the IAC axis, dimension posterior to the IAC axis, and a ratio of posterior-to-anterior dimension (PA ratio).

RESULTS: A total of 127 patients met inclusion criteria. In early follow-up, 60% patients had good (House-Brackmann I-II), and 40% patients had poor (House-Brackmann III-VI) facial function. In long-term follow-up, 71% patients had good, and 29% patients had poor facial function. A total of 72% of patients underwent gross total resection (GTR) of their tumors. Patients with good facial function had significantly larger PA ratios than patients with poor function both early and long term; however, greatest dimension was the more clearly significant independent predictor of facial outcomes. A larger PA ratio was observed in patients in whom GTR was achieved, but this association was potentially confounded by surgeon preferences and was not statistically significant after controlling for surgical site.

CONCLUSIONS: This study demonstrates that VS position relative to the IAC axis can be used along with tumor size to predict postoperative facial outcomes. A greater proportion of tumor posterior to the IAC axis was associated with significantly better facial outcomes.

LEVEL OF EVIDENCE: 4 Laryngoscope, 2021.

PMID:34704617 | DOI:10.1002/lary.29922

Cardiovasc J Afr. 2021 Oct 11;32:1-5. doi: 10.5830/CVJA-2021-047. Online ahead of print.

ABSTRACT

AIM: In this study, we aimed to investigate the effect of the single aortic cross-clamp technique (SCT) (aortic cross-clamp only) versus the multiple-clamp technique (MCT) (aortic cross-clamp + side-biting clamp) on postoperative stroke in octogenarians undergoing coronary artery bypass grafting (CABG).

METHODS: A total of 171 patients aged 80 years and older who underwent isolated CABG were retrospectively analysed. The patients were divided into two groups according to the technique used during surgery: group 1 (n = 88) received the SCT, and group 2 (n = 83) received the MCT. Postoperative stroke was evaluated.

RESULTS: Of the patients, 127 were men and 44 were women. The mean age was 83.05 ± 8.81 years in group 1 and 82.14 ± 8.92 years in group 2. There was no statistically significant difference in the rate of postoperative stroke between the two techniques (p > 0.05).

CONCLUSIONS: Postoperative stroke in octogenarians may result from not only the cross-clamp technique used but also several other factors. We found that both techniques yielded similar outcomes.

PMID:34704588 | DOI:10.5830/CVJA-2021-047

J Pers Assess. 2021 Oct 27:1-13. doi: 10.1080/00223891.2021.1991359. Online ahead of print.

ABSTRACT

The extent to which morality and being a moral person are important to one’s identity is most commonly assessed using Aquino and Reed’s (2002) Self-Importance of Moral Identity Scale (SIMIS). This study provided detailed psychometric examinations of the structure and discrimination levels of the SIMIS in a large (N = 2108) and heterogeneous sample. Results indicated that the SIMIS is clearly 2-dimensional, as expected. The Internalization and Symbolization subscales provided sufficient, and sometimes high levels of test information across the latent trait continuums. There were no redundant items and no bias based on gender. The most notable, albeit minor, shortcomings were that there are too many response options and that test information (discrimination power) was diminished at high levels of the Internalization latent trait continuum, apparently due to skewness. The fluctuating levels of measurement precision resulted in slightly greater attenuations in effect sizes for Internalization than for Symbolization across data for 31 other measures. The present findings from a large dataset and a variety of modern, revealing statistical methods provided relatively consistent, favorable findings for the measure.

PMID:34704515 | DOI:10.1080/00223891.2021.1991359

J Obstet Gynaecol. 2021 Oct 27:1-5. doi: 10.1080/01443615.2021.1962820. Online ahead of print.

ABSTRACT

The rising caesarean section (CS) rate is a complex issue, particularly in an increasingly heterogenous nulliparous population. The study aim was to stratify the CS rate in nulliparous women by age and BMI to determine if any difference existed. This was a retrospective review of CS procedures of nulliparous women in two centres in Ireland (2014 through 2017). Data were obtained for 17,177 women from the hospital databases and CS procedures determined for each age and BMI category. Significant differences were observed when CS rates were stratified in this manner. The CS rates for women <20 years/BMI < 18.5 was 8.8 versus 57.6% for women 35 – 39 years/BMI 30 – 34 and 76 – 100% for all women >45 years (p<.005). The development of customised charts subdivided by age and BMI may be a useful counselling tool and assist in the comparison of rates between units.Impact statementWhat is already known on this subject? It is well known that along with rising CS rates globally, there have also been significant changes in maternal demographics-with increasing maternal age at first birth and increasing maternal BMI. It is well established that both of these factors affect the rate of CS in a population.What do the results of this study add? This study sought to stratify the CS rate in nulliparous women by age and BMI to determine if any difference existed. The results of the study showed an increasing CS rate for increasing age and BMI categories that was statistically significant.What are the implications of these findings for clinical practice and/or further research? Additional research using larger population data sets could allow the development of customised charts for nulliparous women subdivided by age and BMI which could act as a useful counselling tool in clinical practice, as well as assist in the comparison of CS rates between units.

PMID:34704524 | DOI:10.1080/01443615.2021.1962820