Faculty Bibliography
Searched for:
Department/Unit:Population Health
Total Results:
13264
Altered dynamics of visual contextual interactions in Parkinson's disease
Over the last decades, psychophysical and electrophysiological studies in patients and animal models of Parkinson's disease (PD), have consistently revealed a number of visual abnormalities. In particular, specific alterations of contrast sensitivity curves, electroretinogram (ERG), and visual-evoked potentials (VEP), have been attributed to dopaminergic retinal depletion. However, fundamental mechanisms of cortical visual processing, such as normalization or "gain control" computations, have not yet been examined in PD patients. Here, we measured electrophysiological indices of gain control in both space (surround suppression) and time (sensory adaptation) in PD patients based on steady-state VEP (ssVEP). Compared with controls, patients exhibited a significantly higher initial ssVEP amplitude that quickly decayed over time, and greater relative suppression of ssVEP amplitude as a function of surrounding stimulus contrast. Meanwhile, EEG frequency spectra were broadly elevated in patients relative to controls. Thus, contrary to what might be expected given the reduced contrast sensitivity often reported in PD, visual neural responses are not weaker; rather, they are initially larger but undergo an exaggerated degree of spatial and temporal gain control and are embedded within a greater background noise level. These differences may reflect cortical mechanisms that compensate for dysfunctional center-surround interactions at the retinal level.
PMCID:6609710
PMID: 31286057
ISSN: 2373-8057
CID: 4090962
Strengthening Referral Networks for Management of Hypertension Across the Health System (STRENGTHS) in western Kenya: a study protocol of a cluster randomized trial
BACKGROUND:Hypertension is a major risk factor for cardiovascular disease (CVD), yet treatment and control rates for hypertension are very low in low- and middle-income countries (LMICs). Lack of effective referral networks between different levels of the health system is one factor that threatens the ability to achieve adequate blood pressure control and prevent CVD-related morbidity. Health information technology and peer support are two strategies that have improved care coordination and clinical outcomes for other disease entities in other settings; however, their effectiveness and cost-effectiveness in strengthening referral networks to improve blood pressure control and reduce CVD risk in low-resource settings are unknown. METHODS/DESIGN/METHODS:We will use the PRECEDE-PROCEED framework to conduct transdisciplinary implementation research, focused on strengthening referral networks for hypertension in western Kenya. We will conduct a baseline needs and contextual assessment using a mixed-methods approach, in order to inform a participatory, community-based design process to fully develop a contextually and culturally appropriate intervention model that combines health information technology and peer support. Subsequently, we will conduct a two-arm cluster randomized trial comparing 1) usual care for referrals vs 2) referral networks strengthened with our intervention. The primary outcome will be one-year change in systolic blood pressure. The key secondary clinical outcome will be CVD risk reduction, and the key secondary implementation outcomes will include referral process metrics such as referral appropriateness and completion rates. We will conduct a mediation analysis to evaluate the influence of changes in referral network characteristics on intervention outcomes, a moderation analysis to evaluate the influence of baseline referral network characteristics on the effectiveness of the intervention, as well as a process evaluation using the Saunders framework. Finally, we will analyze the incremental cost-effectiveness of the intervention relative to usual care, in terms of costs per unit decrease in systolic blood pressure, per percentage change in CVD risk score, and per disability-adjusted life year saved. DISCUSSION/CONCLUSIONS:This study will provide evidence for the implementation of innovative strategies for strengthening referral networks to improve hypertension control in LMICs. If effective, it has the potential to be a scalable model for health systems strengthening in other low-resource settings worldwide. TRIAL REGISTRATION/BACKGROUND:Clinicaltrials.gov, NCT03543787 . Registered on 29 June 2018.
PMCID:6734355
PMID: 31500661
ISSN: 1745-6215
CID: 4087622
Functional Limitations Mediate the Relationship Between Pain and Depressive Symptoms in Former NFL Athletes
The objective of this study was to analyze data from the National Football League Player Care Foundation Study of Retired NFL Players to understand potential risks for depressive symptoms in former athletes by investigating the relationship between pain and depressive symptoms in a multivariate context, while simultaneously exploring the potential connection with functional limitations. Descriptive statistics were used to describe the study sample and to conduct bivariate comparisons by race and age cohort. Linear regression models were conducted in the subsample of respondents reporting on depressive symptoms using the PHQ-9. Models examine the relationship of bodily pain, injury as a reason for retirement or not re-signing with a team, length of NFL career, sociodemographic characteristics, chronic conditions, and functional limitations to depression. Interaction terms tested whether race and age moderated the effect of bodily pain and functional limitations on depressive symptoms. Bivariate associations revealed no significant differences between younger and older former players in indicators of pain and only slightly higher functional limitations among younger former players. In the multivariate models, pain was significantly associated with depressive symptoms (β = 0.36; p < .01), net of a range of relevant controls. Adding an index of functional limitations reduced this association by nearly half (β = 0.20; p < .01) and functional limitations was significantly associated with depressive symptoms (β = 0.40; p < .01). No statistically significant interactions were found. Overall, bodily pain was strongly associated with depressive symptoms. After accounting for the effects of functional limitations, this association was notably reduced. These results may be useful in identifying aging-related physical declines in relatively younger adult men who may be at the greatest risk for depression. They highlight how physical functionality and activity may mitigate the risk of depression, even in the presence of significant bodily pain.
PMID: 31522600
ISSN: 1557-9891
CID: 4088772
Defining unmet clinical need across the pathway of brain tumor care: a patient and carer perspective
Objective/UNASSIGNED:The aim of this study was to determine the experience of patients with brain tumors and their carers across distinct parts of their treatment pathway and identify their views on potential service gaps in need of addressing. Methods/UNASSIGNED:A structured survey was administered at patient workshops across the UK and online through a charity newsletter. Answers to closed questions were analyzed using descriptive statistics, and open questions were examined using techniques of inductive content analysis. Results/UNASSIGNED:A total of 136 survey responses were received, representing patients with a variety of diagnoses and geographical locations (30 counties). There was a wide range of opinions on the provision of current neuro-oncology services. Key themes identified included a perceived lack of information provision, a gap in postdischarge psychological and neuropsychological supports, and an unmet willingness for involvement in research. Conclusion/UNASSIGNED:This national survey enhances our knowledge of current patient and carer experience within neuro-oncology services. A number of areas of unmet clinical need are highlighted providing a basis for informing future patient-centered service improvements and research.
PMCID:6433107
PMID: 30962709
ISSN: 1179-1322
CID: 4095522
Multi-ancestry genome-wide gene-smoking interaction study of 387,272 individuals identifies new loci associated with serum lipids
The concentrations of high- and low-density-lipoprotein cholesterol and triglycerides are influenced by smoking, but it is unknown whether genetic associations with lipids may be modified by smoking. We conducted a multi-ancestry genome-wide gene-smoking interaction study in 133,805 individuals with follow-up in an additional 253,467 individuals. Combined meta-analyses identified 13 new loci associated with lipids, some of which were detected only because association differed by smoking status. Additionally, we demonstrate the importance of including diverse populations, particularly in studies of interactions with lifestyle factors, where genomic and lifestyle differences by ancestry may contribute to novel findings.
PMCID:6467258
PMID: 30926973
ISSN: 1546-1718
CID: 4094682
Letter to the Editor. Reducing EVD-related infections [Letter]
PMID: 30771776
ISSN: 1933-0693
CID: 4094202
Sex-related differences in homebound advanced Parkinson's disease patients
Background/UNASSIGNED:Women with Parkinson's disease (PD) are more likely to be older, have greater disease severity and comorbidities, and yet are less likely to receive care from a neurologist, as compared with men with PD. Within the PD population, homebound individuals are a particularly vulnerable group facing significant barriers to care, yet within this understudied population, sex-related differences have not been reported. Purpose/UNASSIGNED:To identify and describe differences in homebound men and women with advanced PD and related disorders, participating in an interdisciplinary home visit program. Patients and methods/UNASSIGNED:This was an exploratory analysis of homebound patients seen between February 2014 and July 2016 using data collected via in-person interviews and chart review. Results/UNASSIGNED:=0.05). Conclusion/UNASSIGNED:The role of the caregiver in facilitating safe aging-in-place is crucial. Among homebound individuals with advanced PD, women were far more likely to live alone. The absence of a spouse or care partner may be due in part to variable sex-based life expectancies. Our findings suggest that homebound women with advanced PD may face greater barriers to accessing support.
PMCID:6681424
PMID: 31534322
ISSN: 1178-1998
CID: 4089372
Feasibility and Acceptability of a Culturally Tailored Website to Increase Fruit and Vegetable Intake and Physical Activity Levels in African American Mother-Child Dyads: Observational Study
BACKGROUND:African American youth (aged 8-14 years) do not adhere to national dietary and physical activity guidelines. Nonadherence to these recommendations contributes to disproportionate rates of obesity compared with their white counterparts. Culturally tailored electronic health (eHealth) solutions are needed to communicate nutrition and physical activity messages that resonate with this target population. OBJECTIVE:This study aimed to identify the impact of exposure to a website hosting culturally tailored cartoons to inspire fruit and vegetable uptake and physical activity levels in African American mother-child dyads. METHODS:Statistical analysis included paired sample t tests to evaluate knowledge gains, self-efficacy, and readiness to change. Adapted items from Prochaska's Stages of Change toward the following 4 behaviors were assessed with pre- and posttest surveys: (1) fruit and vegetable selection on my plate, (2) meal preparation, (3) fruit and vegetable selection outside of home, and (4) physical activity. Open-ended comments on videos from mother-child dyads were used to determine user acceptance. Observations of repeated responses during content analysis informed coding and development of key themes. RESULTS:A final sample size of 93 mother-child dyads completed the study. Mothers reported significant improvement from precontemplation or contemplation stages to preparation or action stages for (1) fruit and vegetable selection on her plate (P=.03), (2) meal preparation for her family (P=.01), (3) fruit and vegetable selection outside the home (P<.001), and (4) physical activity (P<.001). Significant improvements were found in knowledge, stage of change, and self-efficacy for the 4 target behaviors of interest (P<.001). Children's open-ended commentary reported vicarious learning and positive character identification with brown-skinned cartoons exhibiting healthful food and exercise behaviors. Mothers commented on the lack of accessible produce in their neighborhoods not depicted in the cartoon videos. CONCLUSIONS:Culturally adapted cartoons that incorporate tailored preferences by African American families, such as race or demography, may help increase adherence to target health behaviors when developing eHealth behavior solutions.
PMCID:6715398
PMID: 31518320
ISSN: 2561-6722
CID: 4088552
Using the Actor-Partner Interdependence Model to assess maternal and infant contributions to mother-infant affective exchanges during the Still-Face Paradigm
This study describes maternal and infant contributions to dyadic affective exchanges during the Still-Face Paradigm (SFP) in an understudied mostly low-income sample. One hundred eleven mothers and their 7-month-old infants were videotaped during the SFP to analyze how a social stressor affects mother-infant positive and negative affective exchanges during interaction. The SFP includes 3 episodes: baseline, maternal still-face, and reunion. Maternal and infant positive and negative affect were scored by masked reliable coders. Data were analyzed using the Actor-Partner Interdependence Model to test the hypotheses that each partner's affectivity during the baseline episode would predict their own affectivity during the reunion episode (actor effects). We also expected that each partner's affectivity during the baseline episode would influence the other partner's affectivity during the reunion episodes (partner effects). After controlling for infant sex and maternal education, results provided evidence for actor effects for maternal and infant positive affect, and for partner effects for maternal baseline positive affect to infant positive affect during the reunion. One significant partner effect was observed for negative affect: Infant negativity during baseline predicted greater maternal negativity during reunion. Findings confirm that both mothers and infants contribute to dyadic affective processes during the SFP but specific findings vary depending on the affective valence in question. Clinical implications and future research are discussed.
PMID: 31445430
ISSN: 1934-8800
CID: 4092082
Sexually transmitted infections. 2019:Conference:(STI):A256-A257.DOI: 10.1136/sextrans-2D2019-2Dsti.644
Demographic, healthcare, and psychosocial factors related to STI diagnosis in a sample of young MSM: The p18 cohort study [Meeting Abstract]
Background Understanding the relationships between demographic, healthcare-related and psychosocial factors with STI vulnerability will provide information that can guide development of STI prevention efforts tailored to the lived realities of YMSM. Methods Between 2009-2011, n=600 YMSM were enrolled at age 18 in a prospective cohort study examining psychosocial and physical health during semi-annual visits conducted over a 36-month period. Reports of recent STIs were collected by self-report and a composite outcome variable was created: self-report of any STI (CT, GC, and/or syphilis) in the prior 90 days (hereafter called STI diagnoses). Bivariate analysis was conducted to examine relationships between STI diagnoses and 3 domains of covariates: demographic factors, psychosocial factors, and healthcare system related factors. Generalized estimating equations (GEE) with link logit was used to model factors from each domain associated with STI diagnoses. Results Over the course of the study period, these 597 participants contributed a total of 2,765 visits and self-reported n=205 STI diagnoses (composite variable detailed above). Increased age was associated with increased likelihood of STI diagnoses (aOR=1.22 per year, 95% CI 1.04-1.43) after adjustment for SES, race, #insertive/receptive anal intercourse acts, type of healthcare obtained (private clinic, public clinic, VA), and insurance status. Black/African YMSM were more likely to self-report an STI (aOR=2.90, 95% CI 1.50-5.61), compared to White (non-hispanic) peers (adjusted for age, SES, #sex acts, clinic type, and insurance). Participants receiving healthcare at public clinics (aOR= 1.89, 95% CI 1.30- 2.77) and VA facilities (aOR= 4.13 95% CI 2.24-7.60) were more likely to report STI diagnoses than those attending private clinics (adjusted for age, race, SES, #sex acts, insurance). Depression score, gay-related stigma, internalized homophobia were not associated with STI diagnoses. Conclusion Older black/african YMSM were more likely to self-report an STI, perhaps because they participant in a different core mixing group of sexual contacts than other participants
EMBASE:629060489
ISSN: 1472-3263
CID: 4071382
