Regression-based estimates of observed functional status in centenarians.
OBJECTIVE
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).


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.


CONCLUSIONS
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.
Mitchell
Meghan B
MB
Geriatric Research Education and Clinical Center, Edith Nourse Memorial Veterans Hospital, Bedford, MA 01730, USA. meghan.mitchell2@va.gov
Miller
L Stephen
LS
Woodard
John L
JL
Davey
Adam
A
Martin
Peter
P
Burgess
Molly
M
Poon
Leonard W
LW
D000203:Activities of Daily Living; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology / Q000523:psychology; D003071:Cognition; D003430:Cross-Sectional Studies; D005260:Female; D005845:Georgia; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D009483:Neuropsychological Tests; D015588:Observer Variation; D011597:Psychomotor Performance; D012043:Regression, Psychology; D057566:Self Report; D012647:Self-Assessment