Relative Strength Of Association Research Articles

Association between hearing loss and suicidal ideation among middle-aged and older adults

Objectives Hearing loss (HL) is regarded as a major risk factor for late-life depression. This study aims to further examine the association between HL and suicidal ideation (SI) among middle-aged and older adults using a nationally representative sample. Method The study sample comprised 34,142 adults (aged 50+) drawn from the 2015 to 2018 National Survey on Drug Use and Health. SI was measured by response to the question, ‘At any time in the past year, did you seriously think about trying to kill yourself?’ HL was assessed by asking respondents whether they were deaf or had serious difficulty hearing. Multivariate logistic regression analyses were conducted to examine the association between HL and SI after adjusting for a comprehensive list of covariates. Results Compared to those without HL, middle-aged and older adults with HL experienced significant health disparities regarding history of hospitalization, poor perceived health, higher prevalence of chronic diseases, depression, substance use, and SI. HL was positively associated with SI in the past year in both middle-aged (aOR = 1.59, 95% CI [1.14, 2.21], p < .001) and older adult groups (aOR = 1.58, 95% CI [1.07, 2.33], p < .001), controlling for depression, substance use, health status, and sociodemographic variables. Conclusion Given the high prevalence of hearing loss (HL) in aging populations, this study aimed to expand our knowledge of the relative strength of association between HL and SI. Findings implied that healthcare providers should consider screening for SI in those with HL.

Predators, prey or temperature? Mechanisms driving niche use of a foundation plant species by specialist lizards.

Foundation species interact strongly with other species to profoundly influence communities, such as by providing food, refuge from predators or beneficial microclimates. We tested relative support for these mechanisms using spinifex grass (Triodia spp.), which is a foundation species of arid Australia that provides habitat for diverse lizard communities. We first compared the attributes of live and dead spinifex, bare ground and a structurally similar plant (Lomandra effusa), and then tested the relative strength of association of two spinifex specialist lizard species (Ctenophorus spinodomus and Ctenotus atlas) with spinifex using a mesocosm experiment. Temperatures were coolest within spinifex compared to bare ground and Lomandra. Invertebrate abundance and the threat of predation were indistinguishable between treatments, suggesting temperature attenuation may be a more important driver. Overall, the dragon C. spinodomus preferred live over dead spinifex, while the skink C. atlas preferred dead spinifex, particularly at warmer air temperatures. However, both species displayed individual variability in their use of available microhabitats, with some individuals rarely using spinifex. Our results provide an example of temperature attenuation by a foundation species driving niche use by ectothermic animals.

Mean Arterial Pressure and Discharge Outcomes in Severe Pediatric Traumatic Brain Injury.

Optimizing blood pressure is an important target for intervention following pediatric traumatic brain injury (TBI). The existing literature has examined the association between systolic blood pressure (SBP) and outcomes. Mean arterial pressure (MAP) is a better measure of organ perfusion than SBP and is used to determine cerebral perfusion pressure but has not been previously examined in relation to outcomes after pediatric TBI. We aimed to evaluate the strength of association between MAP-based hypotension early after hospital admission and discharge outcome and to contrast the relative strength of association of hypotension with outcome between MAP-based and SBP-based blood pressure percentiles. We examined the association between lowest age-specific MAP percentile within 12h after pediatric intensive care unit admission and poor discharge outcome (in-hospital death or transfer to a skilled nursing facility) in children with severe (Glasgow Coma Scale score < 9) TBI who survived at least 12h. Poisson regression results were adjusted for maximum head Abbreviated Injury Scale (AIS) severity score, maximum nonhead AIS, and vasoactive medication use. We also examined the ability of lowest MAP percentile during the first 12h to predict discharge outcomes using receiver operating curve characteristic analysis without adjustment for covariates. We contrasted the predictive ability and the relative strength of association of blood pressure with outcome between MAP and SBP percentiles. Data from 166 children aged < 18years were examined, of whom 20.4% had a poor discharge outcome. Poor discharge outcome was most common among patients with lowest MAP < 5th percentile (42.9%; aRR 5.3 vs. 50-94th percentile, 95% CI 1.2, 23.0) and MAP 5-9th percentile (40%; aRR 8.5, 95% CI 1.9, 38.7). Without adjustment for injury severity or vasoactive medication use, lowest MAP percentile was moderately predictive of poor discharge outcome (AUC: 0.75, 95% CI 0.66, 0.85). In contrast, lowest SBP was associated with poor discharge outcome only for the < 5th percentile (50%; aRR 5.4, 95% CI 1.3, 22.2). Lowest SBP percentile was moderately predictive of poor discharge outcome (AUC: 0.82, 95% CI 0.74, 0.91). In children with severe TBI, a single MAP < 10th percentile during the first 12h after Pediatric Intensive Care Unit admission was associated with poor discharge outcome. Lowest MAP percentile during the first 12h was moderately predictive of poor discharge outcome. Lowest MAP percentile was more strongly associated with outcome than lowest SBP percentile but had slightly lower predictive ability than SBP.

Functional parcellation of the default mode network: a large-scale meta-analysis

The default mode network (DMN) consists of several regions that selectively interact to support distinct domains of cognition. Of the various sites that partake in DMN function, the posterior cingulate cortex (PCC), temporal parietal junction (TPJ), and medial prefrontal cortex (MPFC) are frequently identified as key contributors. Yet, it remains unclear whether these subcomponents of the DMN make unique contributions to specific cognitive processes and health conditions. To address this issue, we applied a meta-analytic parcellation approach used in prior work. This approach used the Neurosynth database and classification methods to quantify the association between PCC, TPJ, and MPFC activation and specific topics related to cognition and health (e.g., decision making and smoking). Our analyses replicated prior observations that the PCC, TPJ, and MPFC collectively support multiple cognitive functions such as decision making, memory, and awareness. To gain insight into the functional organization of each region, we parceled each region based on its coactivation pattern with the rest of the brain. This analysis indicated that each region could be further subdivided into functionally distinct subcomponents. Taken together, we further delineate DMN function by demonstrating the relative strengths of association among subcomponents across a range of cognitive processes and health conditions. A continued attentiveness to the specialization within the DMN allows future work to consider the nuances in sub-regional contributions necessary for healthy cognition, as well as create the potential for more targeted treatment protocols in various health conditions.

Association between 1-mile run times in training and selected predictors: A case study

Runners have an interest in what variables might help them achieve faster run times. In this case study of an individual runner, six predictors are compared to his 1-mile run times over a 1-year period. The six predictors consisted of run sessions (1, 2, etc), outdoor temperature, outdoor humidity, time of day that run began, resting heart rate (HR) on day of run, and heart rate variability also on day of run. Predictors that showed statistically significant correlations were included in multiple linear regression to compare relative strength of association with run times. Two predictors qualified for regression analysis: run session and HR. Both continued to show statistically significant associations in regression.

Association between vision impairment and suicidal ideation among older adults: Results from National Survey on Drug Use and Health

BackgroundVision impairment (VI) is a significant risk factor for depression among older adults. The stigma attached to VI, which has multidimensional aspects consisting of ageism and ableism, may constitute a major impediment to accepting one’s VI and engaging in help-seeking behaviors, which could have led to suicide prevention. ObjectiveThis study aims to investigate the relative strength of association for VI on suicidal ideation among a nationally representative sample of older adults. MethodsThe study sample was composed of 10,635 adults aged 65 years and over, drawn from the 2015–2017 National Survey on Drug Use and Health. Respondents were asked if they had serious thoughts about suicide in the past year. ResultsOf the total sample, 6.85% reported VI (n = 729), defined as being blind or having serious difficulty seeing, even when wearing glasses. In comparison to those without VI, older adults with VI were more likely to report impoverished sociodemographic status and poor health conditions. After adjusting for a comprehensive set of covariates, multivariate logistic regression analyses revealed that older adults with VI were more likely to report suicidal ideation, compared to their counterparts without VI (OR = 3.12, 95% CI [1.24, 7.85]. p < 0. 05). Of the covariates, major depressive episodes presented the strongest positive association with suicidal ideation (OR = 14.11, 95% CI [8.93, 22.29], p < 0. 05). DiscussionThis study contributes to the scant body of literature by identifying the relative strength of association between VI and suicide in a nationally representative sample.

A scoping review of determinants of performance in dressage.

As a first step in achieving an evidence-based classification system for the sport of Para Dressage, there is a clear need to define elite dressage performance. Previous studies have attempted to quantify performance with able-bodied riders using scientific methods; however, definitive measures have yet to be established for the horse and/or the rider. This may be, in part, due to the variety of movements and gaits that are found within a dressage test and also due to the complexity of the horse-rider partnership. The aim of this review is therefore to identify objective measurements of horse performance in dressage and the functional abilities of the rider that may influence them to achieve higher scores. Five databases (SportDiscuss, CINAHL, MEDLINE, EMBASE, VetMed) were systematically searched from 1980 to May 2018. Studies were included if they fulfilled the following criteria: (1) English language; (2) employ objective, quantitative outcome measures for describing equine and human performance in dressage; (3) describe objective measures of superior horse performance using between-subject comparisons and/or relating outcome measures to competitive scoring methods; (4) describe demands of dressage using objective physiological and/or biomechanical measures from human athletes and/or how these demands are translated into superior performance. In total, 773 articles were identified. Title and abstract screening resulted in 155 articles that met the eligibility criteria, 97 were excluded during the full screening of articles, leaving 58 included articles (14 horse, 44 rider) involving 311 equine and 584 able-bodied human participants. Mean ± sd (%) quality scores were 63.5 ± 15.3 and 72.7 ± 14.7 for the equine and human articles respectively. Significant objective measures of horse performance (n = 12 articles) were grouped into themes and separated by gait/movement. A range of temporal variables that indicated superior performance were found in all gaits/movements. For the rider, n = 5 articles reported variables that identified significant differences in skill level, which included the postural position and ROM of the rider’s pelvis, trunk, knee and head. The timing of rider pelvic and trunk motion in relation to the movement of the horse emerged as an important indicator of rider influence. As temporal variables in the horse are consistently linked to superior performance it could be surmised that better overall dressage performance requires minimal disruption from the rider whilst the horse maintains a specific gait/movement. Achieving the gait/movement in the first place depends upon the intrinsic characteristics of the horse, the level of training achieved and the ability of the rider to apply the correct aid. The information from this model will be used to develop an empirical study to test the relative strength of association between impairment and performance in able-bodied and Para Dressage riders.

Physical Discipline, Deprivation, and Differential Risk of Developmental Delay Across 17 Countries

Parenting behaviors have been studied largely in isolation with regard to child development in cross-national contexts. We examine and compare the relative strength of association between physical discipline and deprivation with risk of children's socioemotional and cognitive developmental delay in a cross-national sample. The sample was drawn from the UNICEF Multiple Indicator Cluster Survey. Analyses used observations with data on parental physical discipline, parenting behaviors associated with deprivation, and child developmental outcomes. The present analysis included 29,792 children aged 36-59 months across 17 countries. Using the Early Child Development Index, risk for cognitive or socioemotional developmental delay was indicated if a child could not accomplish 2 or more items within that specific subdomain. Overall risk for delay was indicated if a child was at risk in either subdomain. Associations among discipline, deprivation, and delay were assessed using multivariable logistic regression. Five of the 7 exposures were associated with risk of overall developmental delay. Physical discipline (odds ratio [OR]= 1.49 [95% CI= 1.39, 1.59]; p< .001) had the largest association with risk for socioemotional delay. Not having books (OR= 1.62 [95% CI= 1.42, 1.84]; p< .001) and not counting with the child (OR= 1.47 [95% CI= 1.32, 1.64]; p< .001) had the largest associations with risk of cognitive delay. The exposures of physical discipline and deprivation measured here have distinct associations with risk of socioemotional and cognitive delay cross-nationally. Programmatic and clinical interventions should seek to act on adversities that are relevant to the targeted delay.

Associations of Psychologic Factors with Multiple Chronic Overlapping Pain Conditions.

To characterize psychologic functioning across five chronic overlapping pain conditions (COPCs)-temporomandibular disorders, fibromyalgia, low back pain, headache, and irritable bowel syndrome-and their overlaps. Participants were 655 adults in the OPPERA study. Psychologic variables were standardized in separate logistic regression models to compare their relative strength of association with each COPC. Random forest regression was used to explore the association of all psychologic measures with COPCs simultaneously. Linear regression analyses examined whether the count of COPCs was associated with psychologic measures. In univariate and multivariable analyses, measures of somatic symptom burden showed the strongest associations with individual COPCs and with the number of COPCs. Additional psychologic variables that showed significant associations with individual COPCs and their overlap included negative mood, perceived stress, and pain catastrophizing. These findings highlight the importance of psychologic functioning in the assessment and management of these overlapping pain conditions.

Tobacco Use Among the Youth in India: Evidence From Global Adult Tobacco Survey-2 (2016-2017).

Background:Worldwide, tobacco use is a serious public health concern affecting the youth. A vast majority of tobacco users start using tobacco well before the age of 18 years which has enormous psychosocial and health effects.Objectives:To estimate the prevalence of individual forms of tobacco usage among youth aged 15 to 24 years and to assess the association of sociodemographic factors with tobacco use.Methods:The source of data was a cross-sectional GATS-2 survey in India (analysed using SPSSv17.0) which used a multistage, geographically stratified cluster sampling method. Bivariate analysis was done for evaluation of the possible association of tobacco use with sociodemographic factors. Multivariable logistic regression analysis was conducted to determine the relative strength of association between those factors and tobacco use.Results:There were 13 329 respondents (44.9% males and 55.1% females) aged 15 to 24 years. Overall, 11.9% of respondents were using tobacco. The prevalence of smoke and smokeless tobacco usage was 5% and 10.9%, respectively, whereas 2% of respondents reported dual usage. The odds of using any form of tobacco were significantly higher among respondents aged 20 to 24 years (odds ratio [OR]: 2 [1.76-2.77]) who were primarily residing in rural areas (adjusted odds ratio [aOR]: 1.36 [1.2-1.54]) and were unmarried (aOR: 1.56 [1.37-1.88]). The odds of using any form of tobacco were significantly lower among females (aOR: 0.21 [0.19-0.24]), literate individuals (aOR: 0.33 [0.29-0.37]), and those who were unemployed/students/homemakers (aOR: 0.44 [0.39-0.50]).Conclusions:The overall tobacco usage of 11.9% among young people in the age group of 15 to 24 years is a matter of concern. The study identified several sociodemographic factors significantly associated with tobacco use, implying the need for designing interventions considering social vulnerabilities of youth.

Do Parenting Practices and Child Disclosure Predict Parental Knowledge? A Meta-Analysis.

Parental knowledge of a child's whereabouts, activities, and relationships is one of the most salient factors protecting adolescents against delinquency and misconduct. It is important to understand which strategies are the most effective. Little is known about the relative strength of associations between different parental strategies and parental knowledge, as well as the potential moderating factors of these associations. Seeking to clarify the effectiveness of various strategies in providing parents with knowledge about their adolescent (ages 10-18) offspring's activities and relationships, this meta-analytic review of 32 studies showed that children's disclosure was significantly better than any parental strategy except for parental warmth, which, along with behavioral control, seems to set the stage for the effectiveness of children's disclosure. Consistent with previous findings, psychological control was found to be the strategy with the lowest effect size. Further moderation analyses suggested that behavioral control had a better effect in Eastern than in Western cultures. Longitudinal studies were infrequent and displayed significantly lower effect sizes than one-time (correlational) studies for parental solicitation and children's disclosure. Parental warmth was the best long-acting strategy. The effect of behavioral control was higher for mothers than fathers, suggesting that behavioral control was better executed by mothers. These findings enhance our understanding of primary sources of parental knowledge of adolescents' activities and relationships. Implications for future research and design of interventions are also discussed.

The communicative modus operandi of online child sexual groomers: Recurring patterns in their language use

Online child sexual groomers manipulate their targets into partaking in sexual activity online and, in some cases, offline. To do so they use language (and other semiotic means, such as images) strategically. This study uses a Corpus-Assisted Discourse Studies methodology to identify recurring patterns in online groomers' language use, mapping them to the specific grooming goal that their use in context fulfils. The analysis of the groomers' language (c. 3.3 million words) within 622 conversations from the Perverted Justice website newly identifies 70 such recurring linguistic patterns (three-word collocations), as well as their relative strength of association to one or more grooming goals. The results can be used to inform computational models for detecting online child sexual grooming language. They can also support the development of training resources that raise awareness of typical language structures that characterise online sexual groomers’ communicative modus operandi.

Implicitly measured aggressiveness self-concepts in women with borderline personality disorder as assessed by an Implicit Association Test

BackgroundAggressiveness resulting from inappropriately intense anger plays a major role in borderline personality disorder (BPD) and research using self-report measures has consistently found elevated levels of aggression in this condition. However, while self-report assesses explicit dimensions of the self-concept, it cannot elucidate implicit processes that are at least equally important as they guide the perceptions of the self and influence behavioral responses. The present study aimed to extend the research on aggressiveness self-concepts in BPD utilizing an indirect latency-based measure. MethodsTwenty-nine female inpatients with BPD and 21 healthy women were assessed with an aggressiveness self-concept Implicit Association Test (Agg-IAT) using reaction time measurements to determine the relative strengths of associations between the self vs. others and aggression vs. peacefulness. Additionally, participants completed self-report questionnaires capturing aggressiveness and BPD symptoms. ResultsWomen with BPD had a significantly more aggressive self-concept as indicated by the Agg-IAT than the control group. Moreover, they rated themselves significantly more aggressive on all dimensions than the controls. As expected, correlations between the Agg-IAT and the self-reported aggressiveness dimensions were low (mean r = -.31). LimitationsThe modest sample size and the disregard of a clinical control group limit the generalizability and specificity of our findings. ConclusionsThis study extends prior findings on aggression in BPD in that women with BPD do not only explicitly conceive themselves as more aggressive, but also exhibit implicitly more aggressive self-concepts than healthy controls. Because implicit and explicit self-related operations are related, but distinct processes, our results may hold clinical and therapeutic implications.

Association of Region and Hospital and Patient Characteristics With Use of High-Intensity Statins After Myocardial Infarction Among Medicare Beneficiaries

High-intensity statin use after myocardial infarction (MI) varies by patient characteristics, but little is known about differences in use by hospital or region. To explore the relative strength of associations of region and hospital and patient characteristics with high-intensity statin use after MI. This retrospective cohort analysis used Medicare administrative claims and enrollment data to evaluate fee-for-service Medicare beneficiaries 66 years or older who were hospitalized for MI from January 1, 2011, through June 30, 2015, with a statin prescription claim within 30 days of discharge. Data were analyzed from January 4, 2017, through May 12, 2019. Beneficiary characteristics were abstracted from Medicare data. Hospital characteristics were obtained from the 2014 American Hospital Association Survey and Hospital Compare quality metrics. Nine regions were defined according to the US Census. Intensity of the first statin claim after discharge characterized as high (atorvastatin calcium, 40-80 mg, or rosuvastatin calcium, 20-40 mg/d) vs low to moderate (all other statin types and doses). Trends in high-intensity statins were examined from 2011 through 2015. Associations of region and beneficiary and hospital characteristics with high-intensity statin use from January 1, 2014, to June 15, 2015, were examined using Poisson distribution mixed models. Among the 139 643 fee-for-service beneficiaries included (69 968 men [50.1%] and 69 675 women [49.9%]; mean [SD] age, 76.7 [7.5] years), high-intensity statin use overall increased from 23.4% in 2011 to 55.6% in 2015, but treatment gaps persisted across regions. In models considering region and beneficiary and hospital characteristics, region was the strongest correlate of high-intensity statin use, with 66% higher use in New England than in the West South Central region (risk ratio [RR], 1.66; 95% CI, 1.47-1.87). Hospital size of at least 500 beds (RR, 1.15; 95% CI, 1.07-1.23), medical school affiliation (RR, 1.11; 95% CI, 1.05-1.17), male sex (RR, 1.10; 95% CI, 1.07-1.13), and patient receipt of a stent (RR, 1.35; 95% CI, 1.31-1.39) were associated with greater high-intensity statin use. For-profit hospital ownership, patient age older than 75 years, prior coronary disease, and other comorbidities were associated with lower use. This study's findings suggest that geographic region is the strongest correlate of high-intensity statin use after MI, leading to large treatment disparities.

Predictors of operative mortality among cardiac surgery patients with prolonged ventilation.

Prolonged ventilation after cardiac surgery affects survival and increases morbidity. Previous studies have focused on predicting this complication preoperatively; however, indicators of poor outcome in those requiring prolonged ventilation remain ill-defined. We sought to identify predictors of operative mortality in cardiac surgery patients who experience prolonged mechanical ventilation. 1698 patients who underwent cardiac surgery (CAB, aortic valve replacement ± CAB, or mitral valve repair/replacement ± CAB) required prolonged postoperative mechanical ventilation (>24 hours) between 2012 to 2016 in a statewide consortium. Perioperative factors were evaluated to identify the association with operative mortality. Covariates were selected through bootstrap aggregation to fit multivariable logistic regression models. The relative strength of association was determined by the Wald chi-square statistic. Median patient age was 68 years [IQR 61 to 76], 38% (644/1,698) were female, median duration of mechanical ventilation was 65 hours [IQR 38 to 143], median STS predicted risk of mortality was 3.1% [IQR 1.4 to 6.9%], and 15.7% (266/1698) suffered operative mortality. Among preoperative and operative characteristics, patient age and intraoperative initiation of extracorporeal membrane oxygenation (ECMO) were the strongest correlates of operative mortality on the multivariate analysis. Among postoperative factors, cardiac arrest and renal failure requiring dialysis were the strongest predictors of risk-adjusted operative mortality. Type of operation or surgical center had no association to mortality after risk adjustment. Prolonged ventilation following cardiac surgery is associated with a five-fold increase in operative mortality. In these patients, operative mortality is associated with older age, intraoperative initiation of ECMO, postoperative cardiac arrest, and renal failure requiring dialysis.

Abstract 2206: A new sensitive, accurate liquid chromatography-tandem mass spectrometry (LC-MS-MS) method to measure circulating estrogens, androgens, and progesterone in postmenopausal and premenopausal women

Abstract Endogenous steroid hormones play a critical role in the etiology of breast cancer. However, the interrelationships among estrogens, androgens, and progesterone in determining risk are not well understood. Relative strengths of associations, independent and joint effects, differential effects for tumor subtypes, and effect modification by lifestyle and genetic profile remain unclear. A major reason is the limited accuracy, specificity, and sensitivity of many steroid hormone assays, especially at the low circulating hormone concentrations characteristic of postmenopausal women. CDC developed a new sensitive, accurate isotope dilution LC-MS/MS method capable of measuring eight important steroid hormones in 200 µL of female serum. The method uses sequential liquid-liquid extractions for isolation of estradiol (E2), estrone (E1), estrone sulfate (E1S), testosterone (TT), androstenedione (A), dehydroepiandrosterone sulfate (DHEAS), progesterone (P), and 17-hydroxyprogesterone (17-OHP) without derivatization or hydrolysis. Chromatographic separation of the steroids is carried out using a phenyl-hexyl HPLC column and a gradient of methanol and methanol:water. Scheduled selected reaction monitoring by electrospray ionization in the positive and negative ion modes is applied to quantify the analytes. Two mass transitions, each specific to the fragmentation of the analyte, are monitored for each analyte: quantitation ion (QI) and confirmation ion (CI). The QI to CI ratios are used as criteria to identify possible interferences. The method is able to measure each steroid in nearly all postmenopausal women as well as premenopausal women. Limits of detection in serum-based materials are: E2 1.72 pg/mL, E1 0.13 ng/dL, E1S 2.04 pg/mL, TT 0.57 ng/dL, A 0.82 ng/dL, DHEAS 0.22 µg/dL, P 0.86 ng/dL, and 17-OHP 0.41 ng/dL. Precision, expressed as coefficients of variation and evaluated at three levels for each analyte, ranged from 1.2 to 9.9%. Average bias, a measure of accuracy, ranged from -0.3 to 8.8%. The method is certified through the CDC Hormone Standardization Program for estradiol and testosterone and meets the requirements of the College of American Pathologists Proficiency Testing Program for androgens and progesterone. This new, highly specific and sensitive method demonstrates high accuracy and precision while requiring small amounts of specimens. It can assay up to 140 samples at once. Thus, the method is suitable for large epidemiologic studies investigating the hormonal etiology of breast, endometrial, and ovarian cancer. Citation Format: Lumi Duke, Paul H. Kim, Julianne Cook Botelho, Regina G. Ziegler, Hubert Vesper. A new sensitive, accurate liquid chromatography-tandem mass spectrometry (LC-MS-MS) method to measure circulating estrogens, androgens, and progesterone in postmenopausal and premenopausal women [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2206.

Long-term roosting data reveal a unimodular social network in large fission-fusion society of the colony-living Natterer’s bat (Myotis nattereri)

In many social animals, groups recurrently split into subgroups that regularly re-merge. Such fission-fusion behavior allows individuals to better balance the cost and benefits of group living. However, maintaining a large number of close social links in groups with fission-fusion dynamics may be difficult. It has been suggested that this is the reason why in several species, large groups show more subunits (higher modularity) than do small ones. Many bat species exhibit fission-fusion dynamics in their colonies. This makes them well suited to investigate the proposed link between group size, stability of social links, and group modularity. We studied the daily roosting associations of a Natterer’s bat colony (Myotis nattereri), where up to 80 members carried individual RFID-tags. Based on more than 10,000 individual recordings, we analyzed the influence of relatedness, age, sex, and breeding status on the colony’s social network structure during three breeding seasons. We found an almost fully connected social network with very low modularity and generally weak pairwise associations. Nevertheless, the relative strengths of associations between individuals remained stable across years. Sex, age, and breeding status significantly influenced the strength of an individual’s associations and determined the influence of individuals in the network. In general, associations between bats that were similar in all abovementioned traits were stronger than those between dissimilar individuals. Our results show that despite high fission-fusion dynamics, large colony sizes, and low modularity of their social network, Natterer’s bats were able to maintain stable long-term associations. For a variety of social and ecological reasons, large social groups often consist of several communities with stronger individual bonds within and weaker individual bonds between such social subunits. Unlike that predicted for its relatively large size, the studied Natterer’s bat colony that consisted of up to 80 individually marked bats was not subdivided into communities. Despite the fully connected network, the individual associations were not random. Instead, their strength was mainly driven by relatedness and similarity in age and breeding status of the colony members. Moreover, we found stable long-term pairwise relationships between individuals across several years. Our study shows that despite the strong fission-fusion behavior and large size of their colony, Natterer’s bats formed a fully connected, unimodal social network.

Group Membership, Group Change, and Intergroup Attitudes: A Recategorization Model Based on Cognitive Consistency Principles.

The present article introduces a model based on cognitive consistency principles to predict how new identities become integrated into the self-concept, with consequences for intergroup attitudes. The model specifies four concepts (self-concept, stereotypes, identification, and group compatibility) as associative connections. The model builds on two cognitive principles, balance–congruity and imbalance–dissonance, to predict identification with social groups that people currently belong to, belonged to in the past, or newly belong to. More precisely, the model suggests that the relative strength of self-group associations (i.e., identification) depends in part on the (in)compatibility of the different social groups. Combining insights into cognitive representation of knowledge, intergroup bias, and explicit/implicit attitude change, we further derive predictions for intergroup attitudes. We suggest that intergroup attitudes alter depending on the relative associative strength between the social groups and the self, which in turn is determined by the (in)compatibility between social groups. This model unifies existing models on the integration of social identities into the self-concept by suggesting that basic cognitive mechanisms play an important role in facilitating or hindering identity integration and thus contribute to reducing or increasing intergroup bias.

Preoperative anemia versus blood transfusion: Which is the culprit for worse outcomes in cardiac surgery?

BackgroundReducing blood product utilization after cardiac surgery has become a focus of perioperative care as studies have suggested improved outcomes. The relative impact of preoperative anemia versus packed red blood cells (PRBC) transfusion on outcomes remains poorly understood, however. In this study, we investigated the relative association between preoperative hematocrit (Hct) level and PRBC transfusion on postoperative outcomes after coronary artery bypass grafting (CABG) surgery. MethodsPatient records for primary, isolated CABG operations performed between January 2007 and December 2017 at 19 cardiac surgery centers were evaluated. Hierarchical logistic regression modeling was used to estimate the relationship between baseline preoperative Hct level as well as PRBC transfusion and the likelihoods of postoperative mortality and morbidity, adjusted for baseline patient risk. Variable and model performance characteristics were compared to determine the relative strength of association between Hct level and PRBC transfusion and primary outcomes. ResultsA total of 33,411 patients (median patient age, 65 years; interquartile range [IQR], 57-72 years; 26% females) were evaluated. The median preoperative Hct value was 39% (IQR, 36%-42%), and the mean Society of Thoracic Surgeons (STS) predicted risk of mortality was 1.8 ± 3.1%. Complications included PRBC transfusion in 31% of patients, renal failure in 2.8%, stroke in 1.3%, and operative mortality in 2.0%. A strong association was observed between preoperative Hct value and the likelihood of PRBC transfusion (P < .001). After risk adjustment, PRBC transfusion, but not Hct value, demonstrated stronger associations with postoperative mortality (odds ratio [OR], 4.3; P < .0001), renal failure (OR 6.3; P < .0001), and stroke (OR, 2.4; P < .0001). A 1-point increase in preoperative Hct was associated with decreased probabilities of mortality (OR, 0.97; P = .0001) and renal failure (OR, 0.94; P < .0001). The models with PRBC had superior predictive power, with a larger area under the curve, compared with Hct for all outcomes (all P < .01). Preoperative anemia was associated with up to a 4-fold increase in the probability of PRBC transfusion, a 3-fold increase in renal failure, and almost double the mortality. ConclusionsPRBC transfusion appears to be more closely associated with risk-adjusted morbidity and mortality compared with preoperative Hct level alone, supporting efforts to reduce unnecessary PRBC transfusions. Preoperative anemia independently increases the risk of postoperative morbidity and mortality. These data suggest that preoperative Hct should be included in the STS risk calculators. Finally, efforts to optimize preoperative hematocrit should be investigated as a potentially modifiable risk factor for mortality and morbidity.

Measuring Emergency Department Acuity.

Emergency department (ED) acuity is the general level of patient illness, urgency for clinical intervention, and intensity of resource use in an ED environment. The relative strength of commonly used measures of ED acuity is not well understood. We performed a retrospective cross-sectional analysis of ED-level data to evaluate the relative strength of association between commonly used proxy measures with a full spectrum measure of ED acuity. Common measures included the percentage of patients with Emergency Severity Index (ESI) scores of 1 or 2, case mix index (CMI), academic status, annual ED volume, inpatient admission rate, percentage of Medicare patients, and patients seen per attending-hour. Our reference standard for acuity is the proportion of high-acuity charts (PHAC) coded and billed according to the Centers for Medicare and Medicaid Service's Ambulatory Payment Classification (APC) system. High-acuity charts included those APC 4 or 5 or critical care. PHAC was represented as a fractional response variable. We examined the strength of associations between common acuity measures and PHAC using Spearman's rank correlation coefficients (rs ) and regression models including a quasi-binomial generalized linear model and linear regression. In our univariate analysis, the percentage of patients ESI 1 or 2, CMI, academic status, and annual ED volume had statistically significant associations with PHAC. None explained more than 16% of PHAC variation. For regression models including all common acuity measures, academic status was the only variable significantly associated with PHAC. Emergency Severity Index had the strongest association with PHAC followed by CMI and annual ED volume. Academic status captures variability outside of that explained by ESI, CMI, annual ED volume, percentage of Medicare patients, or patients per attending per hour. All measures combined only explained only 42.6% of PHAC variation.