ELDER-PROXY AGREEMENT CONCERNING THE FUNCTIONAL STATUS AND MEDICAL HISTORY OF THE OLDER PERSON - THE IMPACT OF CAREGIVER BURDEN AND DEPRESSIVE SYMPTOMATOLOGY

OBJECTIVES: To examine the influence of caregiver burden and depressiv e symptomatology on elder-proxy response concordance regarding the old er person's functional status and medical history. DESIGN: Cross-secti onal study via telephone interviews. SETTING: Community-dwelling older people and caregivers in North Carolina. PARTICIPANTS: 340 matched pa irs of frail persons aged 65 and older and their respective caregivers . MEASUREMENTS: Multidimensional Functional Assessment: The OARS metho dology RESULTS: Percent agreement on the ADL items ranged from 97.6% o n personal hygiene to 99.7% for toileting, with moderate kappa coeffic ients. IADL percent agreement ranged from 71.5 to 93.7%, with fair to moderate kappa coefficients. Agreement among the medical history items ranged from 76.3 to 98.5% (kappa =.138-.831). Response bias for the I ADL composite measure is influenced marginally by caregiver burden (F[ 259] = 1.751, P =.098). Five of the individual IADL bias items are inf luenced significantly by burden, such that an increase in burden resul ts in a greater likelihood that the caregiver will overstate disabilit y compared with the rating by the older person. Response bias on the A DL scale was increased among persons who experienced more caregiver bu rden (OR = 1.096, 95% CI = 1.000, 1.192) and those who spent more hour s providing care (OR = 1.012, 95% CI = 1.001, 1.024). Additionally, bl ack caregivers were more likely than white caregivers to disagree with the older people on the ADL scale (OR = 2.73, 95% CI = 1.642, 3.809). A composite of the medical history items is influenced by the relatio nship of the caregiver to the older person; bias is more likely among adult children ((F[227] = 1.56, P =.081). CONCLUSION: Elder-proxy conc ordance is highest among ADL items, followed by medical history items and IADL items. Caregiver depressive symptomotology had no significant impact on elder-proxy response concordance on any of the three outcom es of interest: IADL and medical history bias and ADL disagreement. Ho wever, caregiver burden was marginally predictive of bias on the total ADL and IADL scales. Additionally, increased burden was significantly predictive of bias on five of the seven individual items of the IADL scale, suggesting that the more burden a caregiver feels, the greater likelihood that s/he will overstate the older person's disability comp ared with self-report. These findings suggest that clinicians and rese archers who use proxy reports to determine treatment regimens and comp lete data collection efforts may do so with confidence on ADL individu al items and medical history items when the older person's frailty is marginal. However, caregiver burden may result in misleading represent ation of the older person's functional status, specifically in regard to IADL items.