Systematic review of caregiver responses for patient health-related quality of life in adult cancer care

In surveys and in research, proxies such as family members may be used to assess patient health-related quality of life. The aim of this research is to help cancer researchers select a validated health-related quality of life tool if they anticipate using proxy-reported data. Systematic review and methodological appraisal of studies examining the concordance of paired adult cancer patient and proxy responses for multidimensional, validated HRQOL tools. We searched PubMed, CINAHL, PsycINFO and perused bibliographies of reviewed papers. We reviewed concordance assessment methods, results, and associated factors for each validated tool. A total of 32 papers reporting on 29 study populations were included. Most papers were cross-sectional (N = 20) and used disease-specific tools (N = 19), primarily the FACT and EORTC. Patient and proxy mean scores were similar on average for tools and scales, with most mean differences < 10 points but large standard deviations. Average ICCs for the FACT and EORTC ranged from 0.35 to 0.62, depending on the scale. Few papers (N = 15) evaluated factors associated with concordance, and results and measurement approaches were inconsistent. The EORTC was the most commonly evaluated disease-specific tool (N = 5 papers). For generic tools, both concordance and associated factor information was most commonly available for the COOP/WONCA (N = 3 papers). The MQOL was the most frequently evaluated end-of-life tool (N = 3 papers). Proxy and patient scores are similar on average, but there is large, clinically important residual variability. The evidence base is strongest for the EORTC (disease-specific tools), COOP/WONCA (generic tools), and MQOL (end-of-life-specific tools).