Trials with proxy-reported outcomes registered on the Australian New Zealand Clinical Trials Registry (ANZCTR)
Mercieca Bebber, R and Williams, D and Tait, MA and Rutherford, C and Busija, L and Roberts, N and Wilson, M and Sundaram, CS and Roydhouse, J, Trials with proxy-reported outcomes registered on the Australian New Zealand Clinical Trials Registry (ANZCTR), Quality of Life Research, 28 pp. 955-962. ISSN 1573-2649 (2019) [Refereed Article]
Aims A proxy is someone other than a patient who reports a patientís outcomes as if they are the patient. Due to known
discordance with patient reports, proxies are often not recommended in clinical trials; however, proxies may be needed in
certain research contexts. We aimed to identify and describe trials registered on the Australian New Zealand Clinical Trials
Registry (ANZCTR) with proxy-reported endpoints.
Methods ANZCTR was systematically searched from inception (2005) to 31 March 2017 for trials with proxy-reported
endpoints. Primary and secondary endpoints for each trial retrieved by the search were individually coded (proxy-reported:
yes/no), and trials with confirmed proxy-reported endpoints were included in the analysis.
Results Of 13,666 registered trials, 469 (3.4%) included a proxy-reported endpoint (867 individual proxy-reported endpoints
in total: 62% family member proxy, 22% health professional). Proxy endpoint inclusion did not significantly increase over
time (r=0.18, p=0.59). Mental health (11.5%), stroke (10.3%) and neurological (8.3%) trials had the highest proportion of
trials using proxies. Of the 469 trials, 123 (26.2%) studies involved paediatric patients.
Discussion Proxy-reported endpoints are included in a small but notable number of studies, which may indicate other types
of outcomes are used for patients unable to self-report, or that these patients are under-researched.