Agreement between older adult patient and caregiver proxy symptom reports

Abstract

Background: Proxy report is essential for patients unable to complete patient-reported outcome (PRO) measures themselves and potentially beneficial when the caregiver perspective can complement patient report. In this study, we examine agreement between self-report by older adults and proxy report by their caregivers when completing PROs for pain, anxiety, depression, and other symptoms/impairments. Methods: Four PROs were administered by telephone to older adults and their caregivers followed by re-administration within 24 h in a random subgroup. The PROs included the PHQ-9 depression, GAD-7 anxiety, PEG pain, and SymTrak multi-dimensional symptom and functional status scales. Results: The sample consisted of 576 older adult and caregiver participants (188 patient-caregiver dyads, 200 patients without identified caregiver). The four measures had good internal (Cronbach's alpha, 0.76 to 0.92) and test-retest (ICC, 0.63 to 0.92) reliability whether completed by patients or caregivers. Total score and item-level means were relatively similar for both patient and caregiver reports. Agreement for total score as measured by intraclass correlation coefficient (ICC) was better for SymTrak-23 (0.48) and pain (0.58) than for anxiety (0.28) and depression (0.25). Multinomial modeling showed higher (worse) patient-reported scale scores were associated with caregiver underreporting, whereas higher caregiver task difficulty was associated with overreporting. Conclusion: When averaged over individuals at the group level, proxy reports of PRO scores by caregivers tend to approximate patient reports. For individual patients, proxy report should be interpreted more cautiously for psychological symptoms as well as when patient-reported symptoms are more severe, or caregiver task difficulty is high.