Proxy Measures for Quality of Life in Cancer

In cancer care and research, proxies may be used to report on behalf of patients who cannot self-report. Proxies are especially relevant in specific contexts including paediatric cancer, palliative care and health and experience surveys. The use of proxies can help avoid what would be otherwise missing data and the exclusion of sick and vulnerable patients who may require increased resources as their illness worsens. However, proxy reports are not the same as patient reports, and their use requires careful planning as a result. In this chapter, we discuss key issues including choosing an appropriate proxy, selecting a proxy measure and analysing proxy-reported data. Data collection in specific contexts such as palliative care, paediatric oncology and health surveys will be provided as examples and discussed in depth. Finally, considerations regarding proxy use in both research and routine care settings will be discussed, and areas for future research will be highlighted.