Steven D. Shirk
Edith Nourse Rogers Memorial Veterans Hospital
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Steven D. Shirk.
Alzheimer's Research & Therapy | 2011
Steven D. Shirk; Meghan B. Mitchell; Lynn W. Shaughnessy; Janet C. Sherman; Joseph J. Locascio; Sandra Weintraub; Alireza Atri
IntroductionWith the recent publication of new criteria for the diagnosis of preclinical Alzheimers disease (AD), there is a need for neuropsychological tools that take premorbid functioning into account in order to detect subtle cognitive decline. Using demographic adjustments is one method for increasing the sensitivity of commonly used measures. We sought to provide a useful online z-score calculator that yields estimates of percentile ranges and adjusts individual performance based on sex, age and/or education for each of the neuropsychological tests of the National Alzheimers Coordinating Center Uniform Data Set (NACC, UDS). In addition, we aimed to provide an easily accessible method of creating norms for other clinical researchers for their own, unique data sets.MethodsData from 3,268 clinically cognitively-normal older UDS subjects from a cohort reported by Weintraub and colleagues (2009) were included. For all neuropsychological tests, z-scores were estimated by subtracting the raw score from the predicted mean and then dividing this difference score by the root mean squared error term (RMSE) for a given linear regression model.ResultsFor each neuropsychological test, an estimated z-score was calculated for any raw score based on five different models that adjust for the demographic predictors of SEX, AGE and EDUCATION, either concurrently, individually or without covariates. The interactive online calculator allows the entry of a raw score and provides five corresponding estimated z-scores based on predictions from each corresponding linear regression model. The calculator produces percentile ranks and graphical output.ConclusionsAn interactive, regression-based, normative score online calculator was created to serve as an additional resource for UDS clinical researchers, especially in guiding interpretation of individual performances that appear to fall in borderline realms and may be of particular utility for operationalizing subtle cognitive impairment present according to the newly proposed criteria for Stage 3 preclinical Alzheimers disease.
Journal of Aging Research | 2012
Meghan B. Mitchell; Cynthia R. Cimino; Andreana Benitez; Cassandra L. Brown; Laura E. Gibbons; Robert F. Kennison; Steven D. Shirk; Alireza Atri; Annie Robitaille; Stuart W. S. MacDonald; Magnus Lindwall; Elizabeth M. Zelinski; Sherry L. Willis; K. Warner Schaie; Boo Johansson; Roger A. Dixon; Dan Mungas; Scott M. Hofer; Andrea M. Piccinin
Engagement in cognitively stimulating activities has been considered to maintain or strengthen cognitive skills, thereby minimizing age-related cognitive decline. While the idea that there may be a modifiable behavior that could lower risk for cognitive decline is appealing and potentially empowering for older adults, research findings have not consistently supported the beneficial effects of engaging in cognitively stimulating tasks. Using observational studies of naturalistic cognitive activities, we report a series of mixed effects models that include baseline and change in cognitive activity predicting cognitive outcomes over up to 21 years in four longitudinal studies of aging. Consistent evidence was found for cross-sectional relationships between level of cognitive activity and cognitive test performance. Baseline activity at an earlier age did not, however, predict rate of decline later in life, thus not supporting the concept that engaging in cognitive activity at an earlier point in time increases ones ability to mitigate future age-related cognitive decline. In contrast, change in activity was associated with relative change in cognitive performance. Results therefore suggest that change in cognitive activity from ones previous level has at least a transitory association with cognitive performance measured at the same point in time.
Journal of Aging Research | 2012
Magnus Lindwall; Cynthia R. Cimino; Laura E. Gibbons; Meghan B. Mitchell; Andreana Benitez; Cassandra L. Brown; Robert F. Kennison; Steven D. Shirk; Alireza Atri; Annie Robitaille; Stuart W. S. MacDonald; Elizabeth M. Zelinski; Sherry L. Willis; K. Warner Schaie; Boo Johansson; Marcus Praetorius; Roger A. Dixon; Dan Mungas; Scott M. Hofer; Andrea M. Piccinin
The present study used a coordinated analyses approach to examine the association of physical activity and cognitive change in four longitudinal studies. A series of multilevel growth models with physical activity included both as a fixed (between-person) and time-varying (within-person) predictor of four domains of cognitive function (reasoning, memory, fluency, and semantic knowledge) was used. Baseline physical activity predicted fluency, reasoning and memory in two studies. However, there was a consistent pattern of positive relationships between time-specific changes in physical activity and time-specific changes in cognition, controlling for expected linear trajectories over time, across all four studies. This pattern was most evident for the domains of reasoning and fluency.
Journal of Aging Research | 2012
Cassandra L. Brown; Laura E. Gibbons; Robert F. Kennison; Annie Robitaille; Magnus Lindwall; Meghan B. Mitchell; Steven D. Shirk; Alireza Atri; Cynthia R. Cimino; Andreana Benitez; Stuart W. S. MacDonald; Elizabeth M. Zelinski; Sherry L. Willis; K. Warner Schaie; Boo Johansson; Roger A. Dixon; Dan Mungas; Scott M. Hofer; Andrea M. Piccinin
Social activity is typically viewed as part of an engaged lifestyle that may help mitigate the deleterious effects of advanced age on cognitive function. As such, social activity has been examined in relation to cognitive abilities later in life. However, longitudinal evidence for this hypothesis thus far remains inconclusive. The current study sought to clarify the relationship between social activity and cognitive function over time using a coordinated data analysis approach across four longitudinal studies. A series of multilevel growth models with social activity included as a covariate is presented. Four domains of cognitive function were assessed: reasoning, memory, fluency, and semantic knowledge. Results suggest that baseline social activity is related to some, but not all, cognitive functions. Baseline social activity levels failed to predict rate of decline in most cognitive abilities. Changes in social activity were not consistently associated with cognitive functioning. Our findings do not provide consistent evidence that changes in social activity correspond to immediate benefits in cognitive functioning, except perhaps for verbal fluency.
Journal of The International Neuropsychological Society | 2012
Meghan B. Mitchell; Lynn W. Shaughnessy; Steven D. Shirk; Frances M. Yang; Alireza Atri
Accurate measurement of cognitive function is critical for understanding the disease course of Alzheimers disease (AD). Detecting cognitive change over time can be confounded by level of premorbid intellectual function or cognitive reserve and lead to under- or over-diagnosis of cognitive impairment and AD. Statistical models of cognitive performance that include cognitive reserve can improve sensitivity to change and clinical efficacy. We used confirmatory factor analysis to test a four-factor model composed of memory/language, processing speed/executive function, attention, and cognitive reserve factors in a group of cognitively healthy older adults and a group of participants along the spectrum of amnestic mild cognitive impairment to AD (aMCI-AD). The model showed excellent fit for the control group (χ(2) = 100; df = 78; CFI = .962; RMSEA = .049) and adequate fit for the aMCI-AD group (χ(2) = 1750; df = 78; CFI = .932; RMSEA = .085). Although strict invariance criteria were not met, invariance testing to determine if factor structures are similar across groups yielded acceptable absolute model fits and provide evidence in support of configural, metric, and scalar invariance. These results provide further support for the construct validity of cognitive reserve in healthy and memory impaired older adults.
Alzheimer Disease & Associated Disorders | 2017
Sandra Weintraub; Lilah M. Besser; Hiroko H. Dodge; Merilee Teylan; Steven H. Ferris; Felicia C. Goldstein; Bruno Giordani; Joel H. Kramer; David A. Loewenstein; Dan Marson; Dan Mungas; David P. Salmon; Kathleen A. Welsh-Bohmer; Xiao Hua Zhou; Steven D. Shirk; Alireza Atri; Walter A. Kukull; Creighton H. Phelps; John C. Morris
Introduction: The neuropsychological battery of the Uniform Data Set (UDSNB) was implemented in 2005 by the National Institute on Aging (NIA) Alzheimer Disease Centers program to measure cognitive performance in dementia and mild cognitive impairment due to Alzheimer Disease. This paper describes a revision, the UDSNB 3.0. Methods: The Neuropsychology Work Group of the NIA Clinical Task Force recommended revisions through a process of due diligence to address shortcomings of the original battery. The UDSNB 3.0 covers episodic memory, processing speed, executive function, language, and constructional ability. Data from 3602 cognitively normal participants in the National Alzheimer Coordinating Center database were analyzed. Results: Descriptive statistics are presented. Multivariable linear regression analyses demonstrated score differences by age, sex, and education and were also used to create a normative calculator available online. Discussion: The UDSNB 3.0 neuropsychological battery provides a valuable non proprietary resource for conducting research on cognitive aging and dementia.
Journal of Aging Studies | 2017
Ryan T. Daley; Maureen K. O'Connor; Steven D. Shirk; Renée L. Beard
Spouses provide the majority of care for individuals with Alzheimers disease (AD). The qualitative literature suggests that couples adopt one of two perspectives in their accounts of AD: a We/Us approach where couples describe experiences as a composite whole or an I/Me approach where couples describe themselves as experiencing the impact of AD separately. Little is known about how these perspectives relate to the individual characteristics of either affected party. This study investigated the experiences of dyads taking both approaches. Eleven spousal dyads were divided into I/Me (n=5) and We/Us (n=6) groupings based on qualitative analyses completed as part of a larger project. Diagnosed individuals were given measures of cognitive and functional ability and caregivers completed anxiety, depression, burden, relationship satisfaction, and positive aspects of caregiving measures. We found no significant differences between groups on patient cognitive or functional ability, or caregiver anxiety, depression, burden, or relationship satisfaction. However, We/Us caregivers expressed more positive aspects of caregiving than I/Me caregivers. These findings suggest the I/Me approach is not associated with differences in variables of patient cognitive status or functional ability or caregiver emotional health, perceived burden, or relationship satisfaction. Caregivers taking a We/Us approach, however, were able to identify more positive aspects of caregiving. This may be related to mutual compassion, a characteristic of the We/Us approach, which may be protective.
Clinical Gerontologist | 2018
Maureen K. O'Connor; Malissa L. Kraft; Ryan T. Daley; Michael A. Sugarman; Erika L. Clark; Arielle A. J. Scoglio; Steven D. Shirk
ABSTRACT Objective: We conducted a randomized controlled trial of the Aging Well through Interaction and Scientific Education (AgeWISE) program, a 12-week manualized cognitive rehabilitation program designed to provide psychoeducation to older adults about the aging brain, lifestyle factors associated with successful brain aging, and strategies to compensate for age related cognitive decline. Methods: Forty-nine cognitively intact participants ≥ 60 years old were randomly assigned to the AgeWISE program (n = 25) or a no-treatment control group (n = 24). Questionnaire data were collected prior to group assignment and post intervention. Two-factor repeated-measures analyses of covariance (ANCOVAs) were used to compare group outcomes. Results: Upon completion, participants in the AgeWISE program reported increases in memory contentment and their sense of control in improving memory; no significant changes were observed in the control group. Surprisingly, participation in the group was not associated with significant changes in knowledge of memory aging, perception of memory ability, or greater use of strategies. Conclusions: The AgeWISE program was successfully implemented and increased participants’ memory contentment and their sense of control in improving memory in advancing age. Clinical Implications: This study supports the use of AgeWISE to improve perspectives on healthy cognitive aging.
Alzheimers & Dementia | 2014
Alireza Atri; Jessica S. Dodd; Meghan B. Mitchell; Steven D. Shirk; Donald G. McLaren; Brandon A. Ally
carriers, compared to their younger counterparts, demonstrate lower blood flow in right middle frontal gyrus a pattern opposite that of APOE4 noncarriers. This pattern may be part of a cascade of changes in brain structure and function that lead to cognitive decline, but further investigation is required. This research was sponsored by NIH grants R01-AG-031790, ADRC-P50-AG033514, T32-HL-007936, and 1UL1RR025011.
Journal of Interpersonal Violence | 2017
Arielle A. J. Scoglio; Steven D. Shirk; Rani A. Hoff; Marc N. Potenza; Carolyn M. Mazure; Crystal L. Park; Sherry A. McKee; Elizabeth A. Porter; Shane W. Kraus
U.S. combat veterans frequently encounter challenges after returning from deployment, and these challenges may lead to difficulties in psychological and social functioning. Currently, research is limited on gender-related differences within this population, despite female veterans comprising a growing portion of the U.S. military with roles and exposures similar to their male counterparts. Using secondary analysis, we examined 283 returning combat veterans (female = 29.4%) for differences in psychopathology and trauma history. Female veterans were more likely to report a history of sexual trauma than their male counterparts, whereas male veterans were more likely to report greater frequency of gambling in the past year, impulsivity, and hypersexuality. No gender-related differences were identified for depression, anxiety, insomnia, or substance-use disorders, although both men and women veterans had higher rates than those found in the general population. While both male and female combat veterans report various mental health problems as they transition back into civilian life, gender-related differences relating to sexual trauma, hypersexuality, and impulsivity warrant additional investigations with respect to the potential impact they may have on veteran reintegration and treatment.