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Moderators and Mediators of Activity Intolerance Related to Pain

PainSci » bibliography » Cremers et al 2021

Two articles on PainSci cite Cremers 2021: 1. The Complete Guide to Low Back Pain2. Chronic Low Back Pain Is Not So Chronic

PainSci commentary on Cremers 2021: ?This page is one of thousands in the bibliography. It is not a general article: it is focused on a single scientific paper, and it may provide only just enough context for the summary to make sense. Links to other papers and more general information are provided wherever possible.

This is a mediator/moderator analysis of cross-sectional data, so by nature it is both incapable of showing causality … and yet quite prone to that over-interpretation. And the authors do indeed over-interpret, explicitly rationalizing their speculation about causality despite the limitation, and “concluding” that “misconceptions make humans ill, more so with greater symptoms of depression or anxiety.” Their data is consistent with that conclusion, but it cannot otherwise support it. It’s basically a hypothesis posing as conclusion.

Reaching beyond what cross-sectional data can show in this way is hardly unusual — “everybody’s doing it” — but that doesn’t make it right, and it tends to muddy the waters every time. And anything that seems to support a causal role for psychological can and will be weaponized to gaslight pain patients.

When I first encountered this study, I gave it more credit than it deserves — and got corrected. I wrote a short blog post about that.

~ Paul Ingraham

Common issues and characteristics relevant to this paper: ?Scientific papers have many common characteristics, flaws, and limitations, and many of these are rarely or never acknowledged in the paper itself, or even by other reviewers. I have reviewed thousands of papers, and described many of these issues literally hundreds of times. Eventually I got sick of repeating myself, and so now I just refer to a list common characteristics, especially flaws. Not every single one of them applies perfectly to every paper, but if something is listed here, it is relevant in some way. Note that in the case of reviews, the issue may apply to the science being reviewed, and not the review itself.

  1. Exaggeration in the direction of a more interesting result (e.g. speculating about causality in data that only shows correlation).

original abstract Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.

BACKGROUND: There is wide variation in activity intolerance for a given musculoskeletal pathophysiology. In other words, people often experience illness beyond what one would expect given their level of pathophysiology. Mental health (i.e., cognitive bias regarding pain [e.g., worst-case thinking] and psychological distress [symptoms of anxiety and depression]) is an important and treatable correlate of pain intensity and activity intolerance that accounts for much of this variation. This study tested the degree to which psychological distress accentuates the role of cognitive bias in the relationship between pain intensity and activity intolerance. METHODS: We enrolled 125 adults with musculoskeletal illness in a cross-sectional study. Participants completed measures of activity intolerance related to pain (Patient-Reported Outcomes Measurement Information System [PROMIS] Pain Interference Computer Adaptive Test [CAT]) and in general (PROMIS Physical Function CAT]), measures of psychological distress (PROMIS Depression CAT and PROMIS Anxiety CAT), a numeric rating scale (NRS) for pain intensity, measures of pain-related cognitive bias (4-question versions of the Negative Pain Thoughts Questionnaire [NPTQ-4], Pain Catastrophizing Scale [PCS-4], and Tampa Scale for Kinesiophobia [TSK-4]), and a survey of demographic variables. We assessed the relationships of these measures through mediation and moderation analyses using structural equation modeling. RESULTS: Mediation analysis confirmed the large indirect relationship between pain intensity (NRS) and activity intolerance (PROMIS Pain Interference CAT and Physical Function CAT) through cognitive bias. Symptoms of depression and anxiety had an unconditional (consistent) relationship with cognitive bias (NPTQ), but there was no significant conditional effect/moderation (i.e., no increase in the magnitude of the relationship with increasing symptoms of depression and anxiety). CONCLUSIONS: Psychological distress accentuates the role of cognitive bias in the relationship between pain intensity and activity intolerance. In other words, misconceptions make humans ill, more so with greater symptoms of depression or anxiety. Orthopaedic surgeons can approach their daily work with the knowledge that addressing common misconceptions and identifying psychological distress as a health improvement opportunity are important aspects of musculoskeletal care. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights: