Browsing by Author "Callahan, Chris"

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    Chronic Anticholinergic Use and the Aging Brain
    (Wiley, 2013) Cai, Xueya; Campbell, Noll; Khan, Babar; Callahan, Chris; Boustani, Malaz; Medicine, School of Medicine
    Background: Older Americans are facing an epidemic of chronic diseases and are thus exposed to anticholinergics (ACs) that might negatively affect their risk of developing mild cognitive impairment (MCI) or dementia. Objective: To investigate the association between impairment in cognitive function and previous AC exposure. Design: A retrospective cohort study. Setting: Primary care clinics in Indianapolis, Indiana. Participants: A total of 3690 older adults who have undergone cognitive assessment and had a 1-year medication-dispensing record. Outcome: Cognitive function was measured in two sequential steps: a two-step screening process followed by a formal diagnostic process for participants with positive screening results. Exposure: Three patterns of AC exposure were defined by the duration of AC exposure, the number of AC medications dispensed at the same time, and the severity of AC effects as determined by the Anticholinergic Cognitive Burden list. Results: Compared with older adults with no AC exposure and after adjusting for age, race, gender, and underlying comorbidity, the odds ratio for having a diagnosis of MCI was 2.73 (95% confidence interval, 1.27-5.87) among older adults who were exposed to at least three possible ACs for at least 90 days; the odds ratio for having dementia was 0.43 (95% confidence interval, 0.10-1.81). Conclusion: Exposure to medications with severe AC cognitive burden may be a risk factor for developing MCI.
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    Practical clinical tool to monitor dementia symptoms: the HABC-Monitor
    (Dove Press, 2012) Monahan, Patrick O.; Boustani, Malaz A.; Alder, Catherine; Galvin, James E.; Perkins, Anthony J.; Healey, Patrick; Chehresa, Azita; Shepard, Polly; Bubp, Corby; Frame, Amie; Callahan, Chris; Biostatistics and Health Data Science, Richard M. Fairbanks School of Public Health
    Background: Dementia care providers need a clinical assessment tool similar to the blood pressure cuff (sphygmomanometer) used by clinicians and patients for managing hypertension. A "blood pressure cuff " for dementia would be an inexpensive, simple, user-friendly, easily standardized, sensitive to change, and widely available multidomain instrument for providers and informal caregivers to measure severity of dementia symptoms. The purpose of this study was to assess the reliability and validity of the Healthy Aging Brain Care Monitor (HABC-Monitor) for measuring and monitoring the severity of dementia symptoms through caregiver reports. Methods: The first prototype of the HABC-Monitor was developed in collaboration with the Indianapolis Discovery Network for Dementia, which includes 200 members representing 20 disciplines from 20 local organizations, and an expert panel of 22 experts in dementia care and research. The HABC-Monitor has three patient symptom domains (cognitive, functional, behavioral/psychological) and a caregiver quality of life domain. Patients (n = 171) and their informal caregivers (n = 171) were consecutively approached and consented during, or by phone shortly following, a patient's routine visit to their memory care provider. Results: The HABC-Monitor demonstrated good internal consistency (0.73-0.92); construct validity indicated by correlations with the caregiver-reported Neuropsychiatric Inventory (NPI) total score and NPI caregiver distress score; sensitivity to three-month change compared with NPI "reliable change" groups; and known-groups validity, indicated by significant separation of Mini-Mental Status Examination severity groups and clinical diagnostic groups. Although not designed as a screening study, there was evidence for good operating characteristics, according to area under the receiver-operator curve with respect to gold standard clinical diagnoses, relative to Mini-Mental Status Examination or NPI. Conclusion: The HABC-Monitor demonstrates good reliability and validity as a clinically practical multidimensional tool for monitoring symptoms of dementia through the informal caregiver.
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    Statin Use, Incident Dementia and Alzheimer Disease in Elderly African Americans
    (International Society on Hypertension in Blacks, 2015) Hendrie, Hugh C.; Hake, Ann; Lane, Kathleen; Purnell, Christianna; Unverzagt, Frederick; Smith-Gamble, Valerie; Murrell, Jill; Ogunniyi, Adesola; Baiyewu, Olusegun; Callahan, Chris; Saykin, Andrew J.; Taylor, Stanley; Hall, Kathleen; Gao, Su; Department of Neurology, IU School of Medicine
    OBJECTIVE: To investigate the association between statin use, incident dementia, and Alzheimer disease (AD) in a prospective elderly African American cohort. DESIGN: Two stage design with a screening interview followed by a comprehensive in-home assessment conducted over an eight-year period. Diagnoses of incident AD and dementia were made by consensus. Statin use was collected at each evaluation. Measurements of low-density lipoprotein cholesterol (LDL), C-reactive protein (CRP) and APOE genotype were obtained from baseline blood samples. Logistic regression models were used to test the association of statin use on incident dementia and AD and its possible association with lipid and CRP levels. SETTING: Indianapolis, Indiana. PARTICIPANTS: From an original cohort of 2629 participants, a subsample of 974 African Americans aged >70 years with normal cognition, at least one follow up evaluation, complete statin information, and biomarker availability were included. MAIN OUTCOME MEASURES: Incident dementia and incident AD. RESULTS: After controlling for age at diagnosis, sex, education level, presence of the APOE ε4 allele and history of stroke for the incident dementia model, baseline use of statins was associated with a significantly decreased risk of incident dementia (OR=.44, P=.029) and incident AD (OR=.40, P=.029). The significant effect of statin use on reduced AD risk and trend for dementia risk was found only for those participants who reported consistent use over the observational period (incident AD: P=.034; incident dementia: P=.061). Additional models found no significant interaction between baseline statin use, baseline LDL, or CRP level and incident dementia/AD. CONCLUSIONS: Consistent use of statin medications during eight years of follow-up resulted in significantly reduced risk for incident AD and a trend toward reduced risk for incident dementia.