17 research outputs found
Behavioral approach and avoidance in schizophrenia: An evaluation of motivational profiles
a b s t r a c t a r t i c l e i n f o Schizophrenia is associated with motivational deficits that interfere with a wide range of goal directed activities. Despite their clinical importance, our current understanding of these motivational impairments is limited. Furthermore, different types of motivational problems are commonly seen among individuals within the broad diagnosis of schizophrenia. The goal of the current study was to examine whether clinically meaningful subgroups could be identified based on approach and avoidance motivational tendencies. We measured these tendencies in 151 individuals with schizophrenia. Although prior studies demonstrate elevated BIS sensitivity in schizophrenia at the overall group level, none have explored various combinations of BIS/BAS sensitivities within this disorder. Cluster analyses yielded five subgroups with different combinations of low, moderate, or high BIS and BAS. The subgroups had interpretable differences in clinically rated negative symptoms and selfreported anhedonia/socio-emotional attitudes, which were not detectable with the more commonly used linear BIS/BAS scores. Two of the subgroups had significantly elevated negative symptoms but different approach/ avoidance profiles: one was characterized by markedly low BIS, low BAS and an overall lack of social approach motivation; the other had markedly high BIS but moderate BAS and elevated social avoidance motivation. The two subgroups with relatively good clinical functioning showed patterns of BAS greater than BIS. Our findings indicate that there are distinct motivational pathways that can lead to asociality in schizophrenia and highlight the value of considering profiles based on combined patterns of BIS and BAS in schizophrenia. Published by Elsevier B.V
Uncertainty in Meta-Analysis: Bridging the Divide Between Ideal and Available Extracted Data
Meta-analysis in the health sciences combines evidence from multiple studies to derive stronger conclusions about the efficacy of treatments. In the process of data extraction from published papers, it is extremely common for the required data to be ambiguous, incomplete or missing. We consider the case of meta-analysis of odds-ratios with unknown number of events and meta-analysis of mean differences with missing standard errors. Existing approaches consist of computing best-estimates for the missing values then feeding them into the meta-analysis as extracted data without accounting for the uncertainty of the computations. These naive approaches lead to over-certain results and potentially inaccurate conclusions. Meta-analysis of odds-ratios assumes binomially distributed numbers of events in each treatment group and requires extracted number of events, which are often not available due to loss to follow-up. Common practice consists of inferring the probability of survival from measurements of the Kaplan Meier survival plot and then using it to infer the number of deaths. We propose the Uncertain Reading-Estimated Events model to construct each study's contribution to the meta-analysis separately using the data available for extraction. In our meta-analysis comparing CABG and PCI for ULMCA stenosis, accounting for the uncertainty results in increased standard deviations of the log-odds as compared to a naive meta-analysis that assumes ideal extracted data, equivalent to a reduction of the overall sample size of 43\% in our example. Simulations show that meta-analysis based on the observed number of deaths lead to biased estimates while our model does not. Meta-analysis of mean differences requires extracted mean differences and their standard errors (SE). However, missing standard errors are pervasive in publications. An algebraic computation to recover the missing SE utilizes the baseline and follow-up standard deviations, and correlations, which are also typically missing. Traditional approaches, that have not been theoretically derived, replace missing SEs with various single-value imputations. We formally derive the Uncertain Standard Error Bayesian model to accommodate multiple patterns of missingness in the standard deviations. In our meta-analysis comparing home monitoring blood pressure to usual care, accounting for the uncertainty results in larger posterior SEs compared to the traditional approaches
Prognostic model to identify and quantify risk factors for mortality among hospitalised patients with COVID-19 in the USA
Objectives To develop a prognostic model to identify and quantify risk factors for mortality among patients admitted to the hospital with COVID-19.Design Retrospective cohort study. Patients were randomly assigned to either training (80%) or test (20%) sets. The training set was used to fit a multivariable logistic regression. Predictors were ranked using variable importance metrics. Models were assessed by C-indices, Brier scores and calibration plots in the test set.Setting Optum de-identified COVID-19 Electronic Health Record dataset including over 700 hospitals and 7000 clinics in the USA.Participants 17 086 patients hospitalised with COVID-19 between 20 February 2020 and 5 June 2020.Main outcome measure All-cause mortality while hospitalised.Results The full model that included information on demographics, comorbidities, laboratory results, and vital signs had good discrimination (C-index=0.87) and was well calibrated, with some overpredictions for the most at-risk patients. Results were similar on the training and test sets, suggesting that there was little overfitting. Age was the most important risk factor. The performance of models that included all demographics and comorbidities (C-index=0.79) was only slightly better than a model that only included age (C-index=0.76). Across the study period, predicted mortality was 1.3% for patients aged 18 years old, 8.9% for 55 years old and 28.7% for 85 years old. Predicted mortality across all ages declined over the study period from 22.4% by March to 14.0% by May.Conclusion Age was the most important predictor of all-cause mortality, although vital signs and laboratory results added considerable prognostic information, with oxygen saturation, temperature, respiratory rate, lactate dehydrogenase and white cell count being among the most important predictors. Demographic and comorbidity factors did not improve model performance appreciably. The full model had good discrimination and was reasonably well calibrated, suggesting that it may be useful for assessment of prognosis
Associations between oxytocin receptor genotypes and social cognitive performance in individuals with schizophrenia.
Individuals with schizophrenia often show substantial deficits in social cognitive abilities, which are strongly associated with social functioning. To advance our understanding of the genetic variation that is associated with social cognitive deficits in schizophrenia, we genotyped 74 schizophrenia outpatients who completed social cognitive performance measures assessing mentalizing, social perception, and emotional intelligence, as well as clinical symptoms. We assessed seven single nucleotide polymorphisms (SNPs) of the oxytocin receptor (OXTR) previously found to show replicable associations with socio-emotional processes. For one of the seven SNPs, rs2268493, the 'T' allele was significantly associated with poorer performance on a composite social cognition index, as well as specific tests of mentalizing and social perception. None of the SNPs were associated with clinical symptoms. Though the sample size is small, these findings provide initial support for the involvement of genetic variants of the OXTR in social cognitive impairments in schizophrenia
Effects of Animal Source Food Supplementation on Neurocognitive Outcomes of HIV-Affected Kenyan School-Aged Children: A Randomized, Double-blind, Controlled Intervention Trial
Assess the effects of animal source food (ASF) versus soy versus wheat biscuit supplementation on the neurocognitive performance of HIV-affected, nutritionally at-risk school-aged children in rural Kenya
Deconstructing Bipolar Disorder and Schizophrenia: A cross-diagnostic cluster analysis of cognitive phenotypes
BackgroundBipolar disorder (BD) and schizophrenia (SZ) show substantial overlap. It has been suggested that a subgroup of patients might contribute to these overlapping features. This study employed a cross-diagnostic cluster analysis to identify subgroups of individuals with shared cognitive phenotypes.Method143 participants (68 BD patients, 39 SZ patients and 36 healthy controls) completed a battery of EEG and performance assessments on perception, nonsocial cognition and social cognition. A K-means cluster analysis was conducted with all participants across diagnostic groups. Clinical symptoms, functional capacity, and functional outcome were assessed in patients.ResultsA two-cluster solution across 3 groups was the most stable. One cluster including 44 BD patients, 31 controls and 5 SZ patients showed better cognition (High cluster) than the other cluster with 24 BD patients, 35 SZ patients and 5 controls (Low cluster). BD patients in the High cluster performed better than BD patients in the Low cluster across cognitive domains. Within each cluster, participants with different clinical diagnoses showed different profiles across cognitive domains.LimitationsAll patients are in the chronic phase and out of mood episode at the time of assessment and most of the assessment were behavioral measures.ConclusionsThis study identified two clusters with shared cognitive phenotype profiles that were not proxies for clinical diagnoses. The finding of better social cognitive performance of BD patients than SZ patients in the Lowe cluster suggest that relatively preserved social cognition may be important to identify disease process distinct to each disorder
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The association between self-rated eating habits and dietary behavior in two Latino neighborhoods: Findings from Proyecto MercadoFRESCO.
ObjectiveLatinos are the largest racial and ethnic minority group in the United States and bear a disproportionate burden of obesity related chronic disease. Despite national efforts to improve dietary habits and prevent obesity among Latinos, obesity rates remain high. The objective of this study is to explore the relationship between self-rated dietary quality and dietary behavior among Latinos and how this may vary by socio-demographics to help inform future public health efforts aiming to improve eating habits and obesity rates.DesignCross-sectional study using a series of chi-square tests, the non-parametric Wilcoxon-Mann-Whitney test and logistic regression to explore self-rated eating habits.SettingTwo urban, low-income, predominantly Latino neighborhoods in Los Angeles County.Subjects1000 adults who self-identified as their household's primary food purchaser and preparer were interviewed from 2012 to 2013. Households were randomly selected based on their proximity to corner stores participating in a project to improve the food environment.ResultsMost respondents (59%) report "good" eating habits. Significant associations between "good" eating habits and overall health, fruit and vegetable consumption were observed (p < 0.001). Despite these promising findings, we also find high levels of regular soda and energy-dense food consumption.ConclusionThis study revealed a general understanding that healthy dietary habits are associated with fruit and vegetable consumption among Latinos in two urban neighborhoods. However, there is a need for more targeted health promotion and nutrition education efforts on the risks associated with soda and energy-dense food consumption to help improve dietary habits and obesity levels in low-income Latino communities
Effects of biscuit-type feeding supplementation on the neurocognitive outcomes of HIV-affected school-age children: a randomized, double-blind, controlled intervention trial in Kenya
Objective: To determine if meat or soy protein dietary supplementation will enhance the neurocognitive performance of HIV-affected children at-risk of malnutrition and food insecurity. Methods: A randomized, double-blind, controlled intervention trial evaluated the effect of nutritional supplementation on the neurocognitive outcomes of 49 HIV-affected school-age children in western Kenya. The intervention consisted in providing the mother, target child, and siblings with one of three isocaloric biscuit-type supplements – soy, wheat, or beef – on 5 days per week for 18 months. Neurocognitive outcomes of the target children were assessed by a battery of eight measures and followed up longitudinally for up to 24 months. Results: Mixed effects modeling demonstrated significant differences in the rates of increase over time among all three groups (F test degrees of freedom of 2, P<0.05) for Raven’s progressive matrices performance, but not for verbal meaning, arithmetic, digit span backward, forward, and total, embedded figure test, and Beery visual–motor integration scores. Conclusion: HIV-affected school-age children provided with soy protein supplementation showed greater improvement in nonverbal cognitive (fluid intelligence) performance compared with peers who received isocaloric beef or wheat biscuits. Soy nutrients may have an enhancing effect on neurocognitive skills in HIV-affected school-age children
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Behavioral approach and avoidance in schizophrenia: an evaluation of motivational profiles.
Schizophrenia is associated with motivational deficits that interfere with a wide range of goal directed activities. Despite their clinical importance, our current understanding of these motivational impairments is limited. Furthermore, different types of motivational problems are commonly seen among individuals within the broad diagnosis of schizophrenia. The goal of the current study was to examine whether clinically meaningful subgroups could be identified based on approach and avoidance motivational tendencies. We measured these tendencies in 151 individuals with schizophrenia. Although prior studies demonstrate elevated BIS sensitivity in schizophrenia at the overall group level, none have explored various combinations of BIS/BAS sensitivities within this disorder. Cluster analyses yielded five subgroups with different combinations of low, moderate, or high BIS and BAS. The subgroups had interpretable differences in clinically rated negative symptoms and self-reported anhedonia/socio-emotional attitudes, which were not detectable with the more commonly used linear BIS/BAS scores. Two of the subgroups had significantly elevated negative symptoms but different approach/avoidance profiles: one was characterized by markedly low BIS, low BAS and an overall lack of social approach motivation; the other had markedly high BIS but moderate BAS and elevated social avoidance motivation. The two subgroups with relatively good clinical functioning showed patterns of BAS greater than BIS. Our findings indicate that there are distinct motivational pathways that can lead to asociality in schizophrenia and highlight the value of considering profiles based on combined patterns of BIS and BAS in schizophrenia