Objectives: As the US tests models of care for the seriously ill, patient perceptions of the quality of care are important. Proxies are often needed for this group. We sought to understand the potential impact of proxy reports for the assessment of care quality and experience in cancer.

Methods: Secondary data analysis of a deidentified prospective study that included surveys of perceived care quality, including symptom management, from patients with advanced cancer receiving chemotherapy and their caregivers. Surveys were administered at diagnosis (time 1) and treatment (time 2), with top-box scoring used for analysis. Overall concordance was assessed using metrics including Gwet's AC1. The proportion of the highest scores by respondent type within 2 subgroups were examined: (1) symptom burden and (2) practice setting.

Results: Data from 83 dyads were analyzed. Proxies and patients frequently reported the highest scores for quality (time 1: proxies: 77% and patients: 80%). At time 1, 14% of proxies and 10% of patients reported an unmet need for symptom palliation. Most patients reporting an unmet need gave the top score for quality (75%), but fewer proxies did so (45%). Proxy and patient reports were similar within practice settings. Concordance was at least moderate (nearly all outcomes >0.5 and some >0.8) by Gwet's AC1.

Significance of results: Findings of at least moderate concordance and similar experience outcomes within subgroups suggest the use of proxies may not change estimates substantially. However, consideration should be taken when evaluating symptom management, particularly if such evaluations inform assessment of provider performance.