H Michael Arrighi

Publications (9)35.84 Total impact

• Article: Longitudinal changes in functional disability in Alzheimer's disease patients.

  H Michael Arrighi, Isabelle Gélinas, Trent P McLaughlin, Jacqui Buchanan, Serge Gauthier
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  ABSTRACT: ABSTRACT Background: Functional impairment is a core symptom of Alzheimer's disease (AD) often measured by loss of ability to perform activities of daily living (ADL). The objective is to describe the progressive loss of specific ADL functional capabilities expressed by AD patients' cognitive ability. Methods: Data are from ELN-AIP-901, an observational study of cognitive progression in participants aged 50-85 with AD (n = 196), mild cognitive impairment (n = 70), or cognitively normal (n = 75). Participants were evaluated using the Mini-Mental Status Exam (MMSE) and the Disability Assessment for Dementia (DAD) every six months for ≤2 years. Hierarchical regression was used to estimate annual change in DAD and MMSE; first, by individuals' rate of change using linear regression, then controlling for baseline diagnosis. Results: Over a two-year period, in AD participants, a 1-point change in MMSE was associated with a 3-point change in DAD (2.79, 95% CI: 1.97-3.63); DAD items within the finance, medication, and outings subdomains were impacted earlier than other subdomains; a hierarchy of functional impairment was observed, with instrumental ADL generally impaired prior to basic ADL. Conclusions: ADL are impacted in a progressive and hierarchical manner associated with cognitive decline, but substantial variability remains among individuals, as well as in the relative order of items affected.
  International Psychogeriatrics 02/2013; · 2.24 Impact Factor
• Article: Mild cognitive impairment: disparity of incidence and prevalence estimates.

  Alex Ward, H Michael Arrighi, Shannon Michels, Jesse M Cedarbaum
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  ABSTRACT: The purpose of conducting this study was to identify areas of concordance and sources of variation for the published rates of prevalence and incidence associated with various definitions for mild cognitive impairment (MCI). The study used systematic review of studies published in English since 1984. Studies were identified by searching MEDLINE and EMBASE databases. Population-based observational studies of incidence or prevalence of MCI and related terms were eligible for inclusion. A total of 3,705 citations were identified, and 42 were accepted for inclusion; 35 included data on prevalence and 13 on incidence. The following four terms predominated: age-associated memory impairment (AAMI); cognitive impairment no dementia (CIND); MCI; and amnestic MCI (aMCI). Within each term, the operational definition varied. Substantial variation was observed for both incidence (MCI: 21.5-71.3; aMCI: 8.5-25.9 per 1,000 person-years) and prevalence of each definition of cognitive impairment (AAMI 3.6%-38.4%; CIND 5.1%-35.9%; MCI 3%-42%; aMCI 0.5%-31.9%). CIND and MCI showed increasing prevalence among older age groups, whereas age-specific rates of aMCI were lower and without any apparent age relationship. Prevalence and incidence estimates associated with MCI vary greatly both between definitions and within a definition across the 42 publications. These wide differences pose a significant challenge to our understanding of the social burden of this disease. Enhancement and standardization of operational definitions of the subtypes of cognitive impairment could improve estimates of disease burden and provide a mechanism to assist in the identification of individuals at risk for future Alzheimer's disease and other dementias.
  Alzheimer's & dementia: the journal of the Alzheimer's Association 01/2012; 8(1):14-21. · 5.90 Impact Factor
• Article: Prevalence of apolipoprotein E4 genotype and homozygotes (APOE e4/4) among patients diagnosed with Alzheimer's disease: a systematic review and meta-analysis.

  Alex Ward, Sheila Crean, Catherine J Mercaldi, Jenna M Collins, Dylan Boyd, Michael N Cook, H Michael Arrighi
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  ABSTRACT: Population allele frequencies of apolipoprotein E (APOE) vary by geographic region. The purpose of this study is to summarize and evaluate published estimates for the prevalence of APOE e4 carrier status among the population diagnosed with Alzheimer's disease (AD) by geographic region and country. A systematic review of English-language publications from January 1, 1985, through May 31, 2010, was conducted. Studies reporting APOE e4 status for patients diagnosed with AD were included in the analysis; trials and autopsies were excluded. APOE e4 data were pooled, and prevalence and 95% confidence intervals (CIs) were calculated. Pooled estimates for APOE e4 carrier prevalence data were derived from 142 independent samples: 48.7% (95% CI: 46.5-51.0), and from 73 samples for e4/4 (homozygotes): 9.6% (95% CI: 8.4-10.8). The highest estimates were in Northern Europe: 61.3% (95% CI: 55.9-66.7), e4/4 prevalence: 14.1% (95% CI: 12.2-16.0). The lowest estimates were in Asia and Southern Europe. Substantial heterogeneity of these prevalence estimates was observed. APOE e4 genotype prevalence varies among AD patients by region and within each country. Further exploration is warranted to better understand the substantial heterogeneity of these prevalence estimates.
  Neuroepidemiology 12/2011; 38(1):1-17. · 2.31 Impact Factor
• Article: Apolipoprotein E ε4 prevalence in Alzheimer's disease patients varies across global populations: a systematic literature review and meta-analysis.

  Sheila Crean, Alex Ward, Catherine J Mercaldi, Jenna M Collins, Michael N Cook, Nicole L Baker, H Michael Arrighi
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  ABSTRACT: The ε4 allele of apolipoprotein E (APOE) is associated with Alzheimer's disease (AD). However, attributable risk due to APOE4 varies by region and by race/ethnicity. A literature review and meta-analysis were conducted to estimate the prevalence of APOE4 by geographic area among AD patients. Although estimates varied significantly by study design and case definition, AD patients recruited in Asian and southern European/Mediterranean communities seemed to have significantly lower E4 carrier status estimates (37 and 43%) than those recruited in North America (58%) or northern Europe (64%; all: p < 0.05). APOE4 genotype frequency varies among AD patients in regional patterns similar to that of the general population. Study level differences may also contribute to the heterogeneity of published estimates of APOE4 in AD cases.
  Dementia and Geriatric Cognitive Disorders 01/2011; 31(1):20-30. · 2.14 Impact Factor
• Article: Hip fracture risk and subsequent mortality among Alzheimer's disease patients in the United Kingdom, 1988-2007.

  Nicole L Baker, Michael N Cook, H Michael Arrighi, Roger Bullock
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  ABSTRACT: hip fractures result in a significant burden to the patient, their caregivers and the health care system. Patients with Alzheimer's disease (AD) have a higher incidence of hip fracture compared with other older people without AD, although it is not clear if AD is an independent risk factor for hip fracture. a retrospective cohort study was conducted using anonymised electronic medical records from primary care practices in the United Kingdom. Proportional hazards regression modelling with adjustment for potential confounders was used to evaluate AD as an independent risk factor for predicting hip fractures. the incidence of hip fracture among patients with and without AD was 17.4 (95% CI, 15.7-19.2) and 6.6 (95% CI, 5.8-7.6) per 1,000 person years, respectively. Patients with AD had a hazard that was 3.2 (95% CI, 2.4-4.2) times that of non-AD patients after controlling for potential confounders. AD patients who experienced a hip fracture also had an increased mortality rate compared with non-AD patients who experienced a hip fracture (hazard ratio = 1.5; 95% CI, 1.1-1.9). patients with AD and their caregivers should be advised on how to prevent hip fractures and more attention should be given to AD patients who are undergoing rehabilitation following a hip fracture.
  Age and Ageing 11/2010; 40(1):49-54. · 3.09 Impact Factor
• Source

  Available from: jhsph.edu

  Article: Web-based application to project the burden of Alzheimer's disease.

  Elizabeth Colantuoni, Greg Surplus, Andre Hackman, H Michael Arrighi, Ron Brookmeyer
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  ABSTRACT: Health care planning and research would benefit from tools that enable researchers to project the future burden of Alzheimer's disease (AD) and evaluate the effect of potential interventions. We created a web-based application of the AD prevalence model developed by Brookmeyer et al (Am J Public Health 1998;88:1337-42; Alzheimers Dement 2007;3:186-91). The user defines the disease parameters and any interventions that may either reduce risk or slow disease progression. We expanded the parameters to include the cost and weights for disability-adjusted life years. The secure, web-based application generates detailed AD projections for each calendar year to 2050, and allows users to create personal accounts for them to save, retrieve, and modify the input parameters. The flexibility of the application is illustrated with a forecast for the state of Maryland, USA. The application generates AD burden projections, costs, and disability-adjusted life years, along with changes associated with potential interventions.
  Alzheimer's & dementia: the journal of the Alzheimer's Association 09/2010; 6(5):425-8. · 5.90 Impact Factor
• Article: Burden of Alzheimer's disease and association with negative health outcomes.

  Daniel C Malone, Trent P McLaughlin, Peter M Wahl, Christopher Leibman, H Michael Arrighi, Mark J Cziraky, Lisa M Mucha
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  ABSTRACT: To examine the association of Alzheimer's disease (AD) with common chronic conditions, acute care events, and risk of hospitalization. Retrospective matched cohort analysis. Community-dwelling subjects with a diagnosis of and/or medication for AD were matched to subjects without AD based on age, sex, and geographic region. Administrative claims from commercially insured health plans for medical and pharmacy services provided from January 1, 2000, to March 31, 2006 (inclusive) were analyzed. The Deyo Charlson Index (DCI) was used to assess the number of chronic conditions. The outcomes of interest were risk of fractures and hospitalization. Among 5396 persons with AD and a matched cohort of 5396 persons without the condition, subjects with AD were more likely to have a diagnosis for any of the DCI components, had a higher rate of fractures (17.7% vs 7.9%, P <.00) and other urgent medical events (eg, pneumonia 14.0% vs 6.3%, P <.00), and were more likely to be hospitalized (odds ratio = 1.7; 95% confidence interval = 1.5, 1.9). There were significant differences in the medication use between the 2 groups, with the use of psychotics/tranquilizers 9-fold higher among persons with AD. Persons with AD have higher odds of experiencing a fracture, being hospitalized, and requiring other acute care medical services than those without AD. The disease also is associated with a higher prevalence of common chronic conditions.
  The American journal of managed care 09/2009; 15(8):481-8. · 2.46 Impact Factor
• Article: Worldwide variation in the doubling time of Alzheimer's disease incidence rates.

  Kathryn Ziegler-Graham, Ron Brookmeyer, Elizabeth Johnson, H Michael Arrighi
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  ABSTRACT: The doubling time is the number of chronological years for the age-specific incidence rate to double in magnitude. Doubling times describe the rate of increase of the risk of Alzheimer's disease (AD) with advancing age. Estimates of doubling times of AD assist in understanding disease etiology and forecasting future disease prevalence. The objective of this study was to investigate regional and gender differences in the doubling of AD age-specific incidence rates. We identified all studies in the peer review literature that reported age-specific incidence rates for AD. We modeled the logarithm of the incidence rate as a linear function of age. We used both fixed effects models and random effects models to account for interstudy variation. AD incidence rates exponentially increase with increasing age. The overall estimate of the doubling time was 5.5 years. The doubling times from studies performed in North America and Europe were 6.0 and 5.8, respectively; whereas the doubling times in all other parts of the world were 5.0. There was no significant geographic differences in doubling times (P = .3). Although the doubling times were slightly longer for men (6.5 years) than for women (5.4 years), the difference was not significant (P = .3). Doubling times of AD incidence rates are not statistically significantly different among populations throughout the world. The risk of AD grows exponentially with age, doubling approximately every 5 to 6 years. Although the shapes of the incidence curves are similar, there is considerable variation in absolute incidence rates throughout the world. Currently, there are limited epidemiologic data at the oldest ages, and further study is needed to accurately define the incidence curve above age 90.
  Alzheimer's & dementia: the journal of the Alzheimer's Association 10/2008; 4(5):316-23. · 5.90 Impact Factor
• Source

  Available from: psu.edu

  Article: Forecasting the global burden of Alzheimer's disease.

  Ron Brookmeyer, Elizabeth Johnson, Kathryn Ziegler-Graham, H Michael Arrighi
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  ABSTRACT: Our goal was to forecast the global burden of Alzheimer's disease and evaluate the potential impact of interventions that delay disease onset or progression. A stochastic, multistate model was used in conjunction with United Nations worldwide population forecasts and data from epidemiological studies of the risks of Alzheimer's disease. In 2006, the worldwide prevalence of Alzheimer's disease was 26.6 million. By 2050, the prevalence will quadruple, by which time 1 in 85 persons worldwide will be living with the disease. We estimate about 43% of prevalent cases need a high level of care, equivalent to that of a nursing home. If interventions could delay both disease onset and progression by a modest 1 year, there would be nearly 9.2 million fewer cases of the disease in 2050, with nearly the entire decline attributable to decreases in persons needing a high level of care. We face a looming global epidemic of Alzheimer's disease as the world's population ages. Modest advances in therapeutic and preventive strategies that lead to even small delays in the onset and progression of Alzheimer's disease can significantly reduce the global burden of this disease.
  Alzheimer's & dementia: the journal of the Alzheimer's Association 08/2007; 3(3):186-91. · 5.90 Impact Factor