Who decides what matters in a clinical trial of cognitive remediation?

by Xiaoyu Zhang, PhD Candidate at King’s Health Economics at King’s College London

Clinical trials usually compare a new treatment with the one usually provided. The benefit of the new treatment is measured using a single measure called the “primary outcome”. But recovery in mental health rarely comes down to one measure.

For one person experiencing psychosis, improvement following a therapy might mean better thinking skills, and for others it might mean being able to do more activities during the day, achieving personal goals, or simply feeling that life has improved. These are all reasonable ways to judge whether a treatment has helped.

This raises an obvious question for cognitive remediation therapies: do our studies capture the outcomes that people actually care about? We explored this question using data from the CIRCuiTS™ trial. We asked three groups - people with lived experience, clinical staff working in early intervention services, and service managers - to rank all 8 measures in the trial according to their importance – that is, what they valued.

Agreement was stronger than expected. Participants consistently rated achieving personal goals and quality of life as their top priorities. This is encouraging, given that goal attainment was the primary outcome in the original trial.

But there were also some interesting differences. People with lived experience placed greater importance, compared to healthcare professionals, on increasing the number of activities they could do in everyday life. Staff, on the other hand, tended to place more weight on quality of life and self-esteem. None of these differences are surprising, but they remind us that recovery can look different depending on where you stand.

We then asked another question. Would these different priorities change how we interpret the trial results?

To explore this, we used a method called multi-criteria decision modelling, which allows several outcomes to be combined into a composite score that gives more weight to the outcomes people consider most important.

The main conclusion did not change. Cognitive remediation therapy with CIRCuiTS™ delivered in group or one-to-one formats still showed clear benefits compared with treatment as usual. But the analysis did reveal something more subtle. When only service-user priorities were used, the benefit of group therapy alone was less clear. This does not mean the treatment does not work in a group. Rather, it shows that the way we value outcomes can influence how treatment effects appear.

Clinical trials will probably always rely on a primary outcome. But studies like this suggest that we should also ask whose priorities shape the way we judge success. If trials are to inform clinical services, the outcomes they measure need to reflect what matters to the people who use and deliver those services.

The full paper is available from Schizophrenia Bulletin: https://academic.oup.com/schizophreniabulletin/article/52/3/sbag006/8658221