Search

Daniel Clark, PhD

PRINT THIS PAGE

General Internal Medicine

Associate Professor of Medicine
Center Scientist, Indiana University Center for Aging Research
Investigator, Regenstrief Institute, Inc.

Academic Office

Health Information and Translational Sciences, Suite 2000
410 W. 10th St.
Indianapolis IN 46202-3012 Map

Contact Information

Phone: (317) 274-9235
Email:

Research Interests

Dr. Clark evaluates how preventive health interventions can be applied to elderly, vulnerable populations. His primary research interests are in the identification and modification of risk factors for chronic disease and physical impairment among socioeconomically disadvantaged adults.

Clinical Interests

N/A

Education and Training

Fellowship-Postdoctoral Fellow in Health Promotion and Chronic Disease Prevention Center for Health Studies, Group Health Cooperateive of Puget Sound
Sociology Duke University
Predoctoral Trainee - National Institute on Aging Predoctoral Trainee in Medical Demography and Social Epidemiology Duke University, Durham, NC
M.A., Sociology Duke University, Durham, NC
Sociology Whitworth College
Predoctoral Trainee - National Institute on Aging Predoctoral Trainee in Medical Demography and Social Epidemiology Duke University, Durham, NC
M.A., Sociology Duke University, Durham, NC

Publications (20)¹

Errors in self-reports of health services use: impact on Alzheimer disease clinical trial designs.
Journal: Alzheimer disease and associated disorders
Authors: Callahan CM; Tu W; Stump TE; Clark DO; Unroe KT; Hendrie HC;
Publication Date: 2015 Jan

Abstract

Most Alzheimer disease clinical trials that compare the use of health services rely on reports of caregivers. The goal of this study was to assess the accuracy of self-reports among older adults with Alzheimer disease and their caregiver proxy respondents. This issue is particularly relevant to Alzheimer disease clinical trials because inaccuracy can lead both to loss of power and increased bias in study outcomes.
View details for PubMedID 24845761
Weight loss attitudes and social forces in urban poor black and white women.
Journal: American journal of health behavior
Authors: Keith NR; Hemmerlein KA; Clark DO;
Publication Date: 2015 Jan

Abstract

To explore differences between Blacks and Whites in perceived influences on weight-related behaviors among obese urban poor women.
View details for PubMedID 25290595
Use of a multiparty web based videoconference support group for family caregivers.
Journal: Dementia (London, England)
Authors: Austrom MG; Geros KN; Hemmerlein K; McGuire SM; Gao S; Brown SA; Callahan CM; Clark DO;
Publication Date: 2014 Jul 25

Abstract

This article describes a pilot of a weekly web based videoconference support group for five caregivers of persons with dementia. All participants reported positive views of the group and videoconference medium. Improvements in caregiver anxiety, depression, and physical health scores were observed. Depression scores remained the same with difficulties experienced by the caregiver increasing slightly. Self-efficacy for controlling upsetting thoughts and responding to disruptive behavior improved but worsened slightly for obtaining respite. We concluded that web based support was a positive experience for caregivers, providing them with an acceptable, feasible, low-cost technological alternative to in person support that reduced barriers to attendance by being available in homes.
View details for PubMedID 25062788
Redefined blood pressure variability measure and its association with mortality in elderly primary care patients.
Journal: Hypertension
Authors: Gao S; Hendrie HC; Wang C; Stump TE; Stewart JC; Kesterson J; Clark DO; Callahan CM;
Publication Date: 2014 May 5

Abstract

Visit-to-visit blood pressure (BP) variability has received considerable attention recently. The objective of our study is to define a variability measure that is independent of change over time and determine the association between longitudinal summary measures of BP measurements and mortality risk. Data for the study came from a prospective cohort of 2906 adults, aged =60 years, in an urban primary care system with =15 years of follow-up. Dates of death for deceased participants were retrieved from the National Death Index. Systolic and diastolic BP measurements from outpatient clinic visits were extracted from the Regenstrief Medical Record System. For each patient, the intercept, regression slope, and root mean square error for visit-to-visit variability were derived using linear regression models and used as independent variables in Cox proportional hazards models for both all-cause mortality and mortality attributable to coronary heart disease or stroke. Rate of change was associated with mortality risk in a U-shaped relationship and that participants with little or no change in BP had the lowest mortality risk. BP variability was not an independent predictor of mortality risk. By separating change over time from visit-to-visit variability in studies with relatively long follow-up, we demonstrated in this elderly primary care patient population that BP changes over time, not variability, were associated with greater mortality risk. Future research is needed to confirm our findings in other populations.
View details for PubMedID 24799611
Obesity and 10-year mortality in very old African Americans and Yoruba-Nigerians: exploring the obesity paradox.
Journal: The journals of gerontology. Series A, Biological sciences and medical sciences
Authors: Clark DO; Gao S; Lane KA; Callahan CM; Baiyewu O; Ogunniyi A; Hendrie HC;
Publication Date: 2014 Apr 2

Abstract

To compare the effect of obesity and related risk factors on 10-year mortality in two cohorts of older adults of African descent; one from the United States and one from Nigeria.
View details for PubMedID 24694355
Cognitive function, body mass index and mortality in a rural elderly Chinese cohort.
Journal: Archives of public health = Archives belges de santé publique
Authors: Gao S; Jin Y; Unverzagt FW; Cheng Y; Su L; Wang C; Ma F; Hake AM; Kettler C; Chen C; Liu J; Bian J; Li P; Murrell JR; Clark DO; Hendrie HC;
Publication Date: 2014 Mar 26

Abstract

Previous studies have shown that poor cognition and low body mass index were associated with increased mortality. But few studies have investigated the association between cognition and mortality across the entire cognitive spectrum while adjusting for BMI. The objective of this study is to examine the associations between cognitive function, BMI and 7-year mortality in a rural elderly Chinese cohort.
View details for PubMedID 24666663
Increase in blood pressure precedes clinical depression in elderly primary care patients.
Journal: International journal of geriatric psychiatry
Authors: Gao S; Hendrie HC; Yang L; Stump TE; Stewart JC; Kesterson J; Clark DO; Callahan CM;
Publication Date: 2013 Oct
Hospital and nursing home use from 2002 to 2008 among U.S. older adults with cognitive impairment, not dementia in 2002.
Journal: Alzheimer disease and associated disorders
Authors: Clark DO; Stump TE; Tu W; Miller DK; Langa KM; Unverzagt FW; Callahan CM;
Publication Date: 2013 Oct

Abstract

Little is known about health care use in the cognitive impairment, not dementia (CIND) subpopulation. Using a cohort of 7130 persons aged 71 years or over from the Health and Retirement Survey, we compared mean and total health care use from 2002 to 2008 for those with no cognitive impairment, CIND, or dementia in 2002. Cognitive status was determined using a validated method based on self or proxy interview measures. Health care use was also based on self or proxy reports. On the basis of the Health and Retirement Survey, the CIND subpopulation in 2002 was 5.3 million or 23% of the total population 71 years of age or over. Mean hospital nights was similar and mean nursing home nights was less in persons with CIND compared with persons with dementia. The CIND subpopulation, however, had more total hospital and nursing home nights--71,000 total hospital nights and 223,000 total nursing home nights versus 32,000 hospital nights and 138,000 nursing home nights in the dementia subpopulation. A relatively large population and high health care use result in a large health care impact of the CIND subpopulation.
View details for PubMedID 23151595
Validity and reliability of the Self-Reported Physical Fitness (SRFit) survey.
Journal: Journal of physical activity & health
Authors: Keith NR; Clark DO; Stump TE; Miller DK; Callahan CM;
Publication Date: 2013 May 10

Abstract

An accurate physical fitness survey could be useful in research and clinical care.
View details for PubMedID 23676451
Improving the Validity of Activity of Daily Living Dependency Risk Assessment.
Journal: Journal of applied gerontology : the official journal of the Southern Gerontological Society
Authors: Clark DO; Stump TE; Tu W; Miller DK;
Publication Date: 2013 Jan 17

Abstract

Objectives:Efforts to prevent activity of daily living (ADL) dependency may be improved through models that assess older adults' dependency risk. We evaluated whether cognition and gait speed measures improve the predictive validity of interview-based models.Method:Participants were 8,095 self-respondents in the 2006 Health and Retirement Survey who were aged 65 years or over and independent in five ADLs. Incident ADL dependency was determined from the 2008 interview. Models were developed using random 2/3rd cohorts and validated in the remaining 1/3rd.Results:Compared to a c-statistic of 0.79 in the best interview model, the model including cognitive measures had c-statistics of 0.82 and 0.80 while the best fitting gait speed model had c-statistics of 0.83 and 0.79 in the development and validation cohorts, respectively.Conclusion:Two relatively brief models, one that requires an in-person assessment and one that does not, had excellent validity for predicting incident ADL dependency but did not significantly improve the predictive validity of the best fitting interview-based models.
View details for PubMedID 24652867
Developing a self-reported physical fitness survey.
Journal: Medicine and science in sports and exercise
Authors: Keith NR; Stump TE; Clark DO;
Publication Date: 2012 Jul

Abstract

Physical fitness measures indicate health status, and these can be used to improve management of overall health.
View details for PubMedID 22297807
A comparison and cross-validation of models to predict basic activity of daily living dependency in older adults.
Journal: Medical care
Authors: Clark DO; Stump TE; Tu W; Miller DK;
Publication Date: 2012 Jun

Abstract

A simple method of identifying elders at high risk for activity of daily living (ADL) dependence could facilitate essential research and implementation of cost-effective clinical care programs.
View details for PubMedID 22581013
Exercise adoption among older, low-income women at risk for cardiovascular disease.
Journal: Public health nursing (Boston, Mass.)
Authors: Hays LM; Pressler SJ; Damush TM; Rawl SM; Clark DO;
Publication Date: 2010 Jan

Abstract

Using an expanded Social Cognitive Theory (SCT) model, we hypothesized that self-efficacy, outcome expectations, and exercise self-definition would predict exercise adoption. This secondary analysis examined data from a prospective single-group study of low-income women who received a physician screen and referral to a community-based, free exercise program. The sample included 190 older, low-income women with a mean age of 64 years, the majority of whom were African American (66%) and had at least one cardiovascular risk factor (92%). Baseline values of self-efficacy, outcome expectations, and exercise self-definition were measured using instruments developed for the study. Exercise adoption was defined as the number of exercise sessions completed over 8 weeks. Our hypothesis was tested using hierarchical multiple regression. The mean number of exercise sessions completed over the 8-week period was 5.7 out of a recommended 24. Value of Exercise scores, a subscale of the Exercise Self-Definition scale, predicted exercise adoption. Self-efficacy and outcome expectations were not predictive. The significance of Value of Exercise scores reinforces the importance of expanding SCT with additional variables such as exercise self-definition. Future work should emphasize the social and environmental factors that form an important part of SCT.
View details for PubMedID 20055971
The meaning and significance of self-management among socioeconomically vulnerable older adults.
Journal: The journals of gerontology. Series B, Psychological sciences and social sciences
Authors: Clark DO; Frankel RM; Morgan DL; Ricketts G; Bair MJ; Nyland KA; Callahan CM;
Publication Date: 2008 Sep

Abstract

The aim of this study was to describe and contrast perceptions of self-management among socioeconomically vulnerable and nonvulnerable older adults.
View details for PubMedID 18818452
Design and reach of a primary care weight management program.
Journal: Journal of health care for the poor and underserved
Authors: Clark DO; Keith N; Chrysler L; Perkins AJ; Willis D;
Publication Date: 2008 Feb

Abstract

To report the reach of Take Charge Lite (TCL), a lifestyle weight management program.
View details for PubMedID 18263993
Geriatric care management for low-income seniors: a randomized controlled trial.
Journal: JAMA
Authors: Counsell SR; Callahan CM; Clark DO; Tu W; Buttar AB; Stump TE; Ricketts GD;
Publication Date: 2007 Dec 12

Abstract

Low-income seniors frequently have multiple chronic medical conditions for which they often fail to receive the recommended standard of care.
View details for PubMedID 18073358
Educational disparities in the prevalence and consequence of physical vulnerability.
Journal: The journals of gerontology. Series B, Psychological sciences and social sciences
Authors: Clark DO; Stump TE; Miller DK; Long JS;
Publication Date: 2007 May

Abstract

The purpose of this study was to estimate educational differences in the prevalence and mortality consequence of physical vulnerability among older adults in the United States.
View details for PubMedID 17507595
Geriatric Resources for Assessment and Care of Elders (GRACE): a new model of primary care for low-income seniors.
Journal: Journal of the American Geriatrics Society
Authors: Counsell SR; Callahan CM; Buttar AB; Clark DO; Frank KI;
Publication Date: 2006 Jul

Abstract

The majority of older adults receive health care in primary care settings, yet many fail to receive the recommended standard of care for preventive services, chronic disease management, and geriatric syndromes. The Geriatric Resources for Assessment and Care of Elders (GRACE) model of primary care for low-income seniors and their primary care physicians (PCPs) was developed to improve the quality of geriatric care so as to optimize health and functional status, decrease excess healthcare use, and prevent long-term nursing home placement. The catalyst for the GRACE intervention is the GRACE support team, consisting of a nurse practitioner and a social worker. Upon enrollment, the GRACE support team meets with the patient in the home to conduct an initial comprehensive geriatric assessment. The support team then meets with the larger GRACE interdisciplinary team (including a geriatrician, pharmacist, physical therapist, mental health social worker, and community-based services liaison) to develop an individualized care plan including activation of GRACE protocols for evaluating and managing common geriatric conditions. The GRACE support team then meets with the patient's PCP to discuss and modify the plan. Collaborating with the PCP, and consistent with the patient's goals, the support team then implements the plan. With the support of an electronic medical record and longitudinal tracking system, the GRACE support team provides ongoing care management and coordination of care across multiple geriatric syndromes, providers, and sites of care. The effectiveness of the GRACE intervention is being evaluated in a randomized, controlled trial.
View details for PubMedID 16866688
Reliability and validity of a steadiness score.
Journal: Journal of the American Geriatrics Society
Authors: Clark DO; Callahan CM; Counsell SR;
Publication Date: 2005 Sep

Abstract

To determine the internal consistency and construct and predictive validity of three survey questions regarding steadiness in a sample of community-dwelling lower-income older adults.
View details for PubMedID 16137291
The effects of health and environment on exercise-class participation in older, urban women.
Journal: Journal of aging and physical activity
Authors: Tu W; Stump TE; Damush TM; Clark DO;
Publication Date: 2004 Oct

Abstract

This research investigated the effects of health and environmental factors on the dropout and intermittent nonattendance of an exercise program designed specifically for older, female, primary-care patients living in the inner city. Class-attendance records (n = 21,538) from a cohort 110 women were analyzed. Women who dropped out early had poorer perceived health and were more likely to report pain as an exercise barrier at baseline. Those who lived in a census tract where a larger percentage of workers walk to work were less likely to drop out early. Intermittent nonattendance was associated with adverse weather conditions including heat index above 90 degrees F, wind-chill index below 20 degrees F, overcast sky, and snow. Better attendance was associated with greater atmospheric pressure, as well as lower number of sunlight hours per day. This research highlights the need to better understand environmental barriers when promoting physical activities in older women.
View details for PubMedID 15851821