Re-evaluating randomized clinical trials of psychological interventions: Impact of response shift on the interpretation of trial results, 2021, Verdam

Abstract
Background
Effectiveness of psychological treatment is often assessed using patient-reported health evaluations. However, comparison of such scores over time can be hampered due to a change in the meaning of self-evaluations, called ‘response shift’. Insight into the occurrence of response shift seems especially relevant in the context of psychological interventions, as they often purposefully intend to change patients’ frames of reference.

Aims
The overall aim is to gain insight into the general relevance of response shift for psychological health intervention research. Specifically, the aim is to re-analyse data of published randomized controlled trials (RCTs) investigating the effectiveness of psychological interventions targeting different health aspects, to assess (1) the occurrence of response shift, (2) the impact of response shift on interpretation of treatment effectiveness, and (3) the predictive role of clinical and background variables for detected response shift.

Method
We re-analysed data from RCTs on guided internet delivered cognitive behavioural treatment (CBT) for insomnia in the general population with and without elevated depressive symptoms, an RCT on meaning-centred group psychotherapy targeting personal meaning for cancer survivors, and an RCT on internet-based CBT treatment for persons with diabetes with elevated depressive symptoms. Structural equation modelling was used to test the three objectives.

Results
We found indications of response shift in the intervention groups of all analysed datasets. However, results were mixed, as response shift was also indicated in some of the control groups, albeit to a lesser extent or in opposite direction. Overall, the detected response shifts only marginally impacted trial results. Relations with selected clinical and background variables helped the interpretation of detected effects and their possible mechanisms.

Conclusion
This study showed that response shift effects can occur as a result of psychological health interventions. Response shift did not influence the overall interpretation of trial results, but provide insight into differential treatment effectiveness for specific symptoms and/or domains that can be clinically meaningful.

Open access, https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0252035

 

Is this saying that the McPhee effect is real but we don't think it matters too much?

 

Honestly, of all the factors that make this field of research a muddy mess, "a change in the meaning of self-evaluations" is probably the least of all problems. It's not the patients who change their minds, that rarely happens, it's that everything is arbitrary and detached from reality but that's never taken into account, with as little reliability as movie reviews, probably even less.

But focusing on the least of all problems is a convenient way of ignoring the entire herd of elephants in the room.

 

This happened to me. All it achieved in the beginning was giving me an inferiority complex. It didn't make the pain any easier to cope with.

 

Note,

 

I should add to this, that it also made me believe that a big chunk of the medical profession is malicious and really nasty, a belief that I've never really had much reason to alter throughout my life.