How do proxy responses and proxy-assisted responses differ from what Medicare beneficiaries might have reported about their health care?

OBJECTIVE: Assess proxy respondent effects on health care evaluations by Medicare beneficiaries. DATA SOURCE: 110,215 respondents from the nationally representative 2001 CAHPS((R)) Medicare Fee-for-Service Survey. STUDY DESIGN/DATA COLLECTION/EXTRACTION
METHODS: We compare the effects of both proxy respondents and proxy assistance (reading, writing, or translating) on 23 "objective" report items and four "subjective" global measures of health care experiences using propensity-score-weighted regression. We assess whether proxy effects differ among spouses, other relatives, or nonrelatives. PRINCIPAL
FINDINGS: Proxy respondents provide less positive evaluations of beneficiary health care experiences than otherwise similar self-reporting beneficiaries for more subjective global ratings (average effect of 0.21 standard deviations); differences are smaller for relatively objective and specific report items. Proxy assistance differences are similar, but about half as large. Reports from spouse proxy respondents are more positive than those from other proxies and are similar to what would have been reported by the beneficiaries themselves. Standard regression techniques may overestimate proxy effects in this instance.
CONCLUSIONS: One should treat proxy responses to subjective ratings cautiously. Even seemingly innocuous reading, writing, and translation by proxies may influence answers. Spouses may be accurate proxies for the elderly in evaluations of health care.