Regression-based estimates of observed functional status in centenarians.

PURPOSE OF THE STUDY There is lack of consensus on the best method of functional assessment, and there is a paucity of studies on daily functioning in centenarians. We sought to compare associations between performance-based, self-report, and proxy report of functional status in centenarians. We expected the strongest relationships between proxy reports and observed performance of basic activities of daily living (BADLs) and instrumental activities of daily living (IADLs). We hypothesized that the discrepancy between self-report and observed daily functioning would be modified by cognitive status. We additionally sought to provide clinicians with estimates of centenarians' observed daily functioning based on their mental status in combination with subjective measures of activities of daily living (ADLs). DESIGN AND METHODS Two hundred and forty-four centenarians from the Georgia Centenarian Study were included in this cross-sectional population-based study. Measures included the Direct Assessment of Functional Status, self-report and proxy report of functional status, and the Mini-Mental State Examination (MMSE). RESULTS Associations between observed and proxy reports were stronger than between observed and self-report across BADL and IADL measures. A significant MMSE by type of report interaction was found, indicating that lower MMSE performance is associated with a greater discrepancy between subjective and objective ADL measures. IMPLICATIONS Results demonstrate associations between 3 methods of assessing functional status and suggest proxy reports are generally more accurate than self-report measures. Cognitive status accounted for some of the discrepancy between observed and self-reports, and we provide clinicians with tables to estimate centenarians' performance on observed functional measures based on MMSE and subjective report of functional status.

[1]  Meghan B. Mitchell,et al.  Executive Functioning and Observed Versus Self-Reported Measures of Functional Ability , 2008, The Clinical neuropsychologist.

[2]  M. Lawton,et al.  Assessment of Older People: Self-Maintaining and Instrumental Activities of Daily Living , 1969 .

[3]  W. Hall.  Update in Geriatrics , 2006, Annals of Internal Medicine.

[4]  Janet B W Williams,et al.  Diagnostic and Statistical Manual of Mental Disorders , 2013 .

[5]  S. Mitchell,et al.  The hierarchy of functional loss associated with cognitive decline in older persons. , 2001, The journals of gerontology. Series A, Biological sciences and medical sciences.

[6]  K. Coburn,et al.  The cognitive correlates of functional status , 2007 .

[7]  R. Charter,et al.  Psychometric Properties of the Folstein Mini-Mental State Examination , 2005, Assessment.

[8]  S. Katz.  Studies of illness in the aged , 1963 .

[9]  P J Holliday,et al.  Functional performance measures: are they superior to self-assessments? , 1993, Journal of gerontology.

[10]  R. Kane,et al.  Use of proxy respondents and accuracy of minimum data set assessments of activities of daily living. , 2005, The journals of gerontology. Series A, Biological sciences and medical sciences.

[11]  J. Guralnik,et al.  Performance‐Based Measures of Physical Function for High‐Function Populations , 2006, Journal of the American Geriatrics Society.

[12]  T. Glass.  Conjugating the "tenses" of function: discordance among hypothetical, experimental, and enacted function in older adults. , 1998, The Gerontologist.

[13]  P. Pezzotti,et al.  The accuracy of the MMSE in detecting cognitive impairment when administered by general practitioners : A prospective observational study , 2015 .

[14]  L. Rubenstein,et al.  Systematic biases in functional status assessment of elderly adults: effects of different data sources. , 1984, Journal of gerontology.

[15]  E B Larson,et al.  The Mini-Mental State Examination score and the clinical diagnosis of dementia. , 1994, Journal of Clinical Epidemiology.

[16]  S. Katz,et al.  STUDIES OF ILLNESS IN THE AGED. THE INDEX OF ADL: A STANDARDIZED MEASURE OF BIOLOGICAL AND PSYCHOSOCIAL FUNCTION. , 1963, JAMA.

[17]  W. Satariano,et al.  Reliability of physical performance and self-reported functional measures in an older population. , 1998, The journals of gerontology. Series A, Biological sciences and medical sciences.

[18]  W J MacLennan,et al.  The accuracy of self and informant ratings of physical functional capacity in the elderly. , 1992, Journal of clinical epidemiology.

[19]  I McDowell,et al.  Multidimensionality in instrumental and basic activities of daily living. , 1998, Journal of clinical epidemiology.

[20]  J Ormel,et al.  The assessment of ADL among frail elderly in an interview survey: self-report versus performance-based tests and determinants of discrepancies. , 1996, The journals of gerontology. Series B, Psychological sciences and social sciences.

[21]  Ian R. Cameron,et al.  Multidimensional Functional Assessment: The OARS Methodology. A Manual , 1978 .

[22]  S. Zimmerman,et al.  Proxy reporting in five areas of functional status. Comparison with self-reports and observations of performance. , 1997, American journal of epidemiology.

[23]  L. Miller,et al.  Executive Control Functioning and Functional Ability in Older Adults , 2007, The Clinical neuropsychologist.

[24]  M. Powell Lawton,et al.  Annual Review of Gerontology and Geriatrics , 1988, Springer Berlin Heidelberg.

[25]  Kevin J Black,et al.  The cognitive correlates of functional status: a review from the Committee on Research of the American Neuropsychiatric Association. , 2007, The Journal of neuropsychiatry and clinical neurosciences.

[26]  H. Edelberg,et al.  Medication Management Capacity in Highly Functioning Community‐Living Older Adults: Detection of Early Deficits , 1999, Journal of the American Geriatrics Society.

[27]  M. Folstein,et al.  The Mini-Mental State Examination. , 1983, Archives of general psychiatry.

[28]  G. McDougall,et al.  The revised direct assessment of functional status for independent older adults. , 2010, The Gerontologist.

[29]  B Gittelman,et al.  A new scale for the assessment of functional status in Alzheimer's disease and related disorders. , 1989, Journal of gerontology.

[30]  Y. Stern,et al.  Functional deficits in patients with mild cognitive impairment: Prediction of AD , 2002, Neurology.

[31]  A. Davey,et al.  Statistical Power Analysis with Missing Data: A Structural Equation Modeling Approach , 2009 .

[32]  G. Frisoni,et al.  Contrasting Results Between Caregiver's Report and Direct Assessment of Activities of Daily Living in Patients Affected by Mild and Very Mild Dementia: The Contribution of the Caregiver's Personal Characteristics , 1999, Journal of the American Geriatrics Society.

[33]  R. Garg,et al.  Perceived risks to independent living: the views of older, community-dwelling adults. , 1997, The Gerontologist.

[34]  W. Spector,et al.  The hierarchical relationship between activities of daily living and instrumental activities of daily living. , 1987, Journal of chronic diseases.

[35]  Michael E. Miller,et al.  Changes in cognitive function in a randomized trial of physical activity: results of the lifestyle interventions and independence for elders pilot study. , 2009, The journals of gerontology. Series A, Biological sciences and medical sciences.

[36]  T. Seeman,et al.  The relationship between cognitive and physical performance: MacArthur Studies of Successful Aging. , 2002, The journals of gerontology. Series A, Biological sciences and medical sciences.

[37]  C. Eisdorfer,et al.  Caregivers' judgments of the functional abilities of the Alzheimer's disease patient: a comparison of proxy reports and objective measures. , 2001, The journals of gerontology. Series B, Psychological sciences and social sciences.

[38]  J. DeCoster.  Applied Linear Regression Notes set 1 , 2006 .

[39]  A. Stuck,et al.  Risk factors for functional status decline in community-living elderly people: a systematic literature review. , 1999, Social science & medicine.

[40]  D. Reuben,et al.  Measures of functional status in community-dwelling elders , 1998, Journal of General Internal Medicine.

[41]  W. Spector,et al.  Combining activities of daily living with instrumental activities of daily living to measure functional disability. , 1998, The journals of gerontology. Series B, Psychological sciences and social sciences.

[42]  R. Green,et al.  Methodological Considerations in Studying Centenarians: Lessons Learned From the Georgia Centenarian Studies , 2007, Annual Review of Gerontology and Geriatrics.