Can We Really Compare and Aggregate Patient-reported Outcomes Between People and Settings?

A new OHE Research Paper considers whether we can compare and aggregate patient-reported outcome (PRO) data between people and settings. The paper is authored by Nancy Devlin (University of Melbourne), Paula Lorgelly (King’s College London), and Mike Herdman (OHE).

Clinical trials are increasingly being conducted across multiple countries and regions. The collection of PRO data in these trials, and the practice of pooling data from them in analyses, relies on patients’ responses to PRO instruments being strictly comparable. There are two aspects to this assumption: (a) that the PRO instruments themselves are conceptually and linguistically similar and equally valid when fielded in different cultures and languages, and (b) that the way in which people from different socio-economic or cultural groups self-report their health on those instruments is fundamentally the same.

In practice, there are issues that affect both these aspects and act to limit the comparability of PRO data. This has important implications for the way PROs are developed and tested. It also has implications for the way that evidence from PROs is currently collected and analysed in multi-country clinical trials, health technology assessment, and decisions informed by those data.

Although progress has been made in this area, there is still considerable scope for further research and improved practice. The authors argue that issues of non-comparability in PRO data require renewed attention. Numerous factors can limit the comparability of PRO data across (and potentially within) countries and cultures. Failure to recognise and account for these differences could lead to incorrect conclusions about the effectiveness and cost-effectiveness of new medicines and other health care interventions. The paper recommends further research; strengthened guidelines regarding content validity for PROs intended for use across different settings; and enhanced guidelines for the users of PRO instruments.

For further information on this work, please contact Nancy Devlin.


Devlin, N., Lorgelly, P. and Herdman, M., 2019. Can We Really Compare and Aggregate PRO Data Between People and Settings? Implications for Multi-Country Clinical Trials and HTA. OHE Research Paper.

Posted in EQ-5D and PROMs, Health Technology Assessment, Research | Tagged Research Papers