Responsiveness and meaningful thresholds of PROMIS pain interference, fatigue, ... idiopathic inflammatory myopathies 2023 Saygin et al

Full title: Responsiveness and meaningful thresholds of PROMIS pain interference, fatigue, and physical function forms in adults with idiopathic inflammatory myopathies: Report from the OMERACT Myositis Working Group

Background
A series of qualitative studies conducted by the OMERACT Myositis Working Group identified pain interference, fatigue, and physical function as highly important life impact domains for adults with idiopathic inflammatory myositis (IIM). In this study, our goal was to assess the responsiveness and minimal important difference of PROMIS pain interference (6a), fatigue (7a), and physical function (8b).

Methods
Adults with IIM from USA, Netherlands, Korea, Sweden, and Australia with two "clinical" visits were enrolled in this prospective study. Anchor questions on a Likert scale were collected at baseline, and manual muscle testing (MMT), physician and patient reported global disease activity, and PROMIS instruments were collected at both visits. Responsiveness was assessed with i) ANOVA, ii) paired t-test, effect size and standardized response mean, and iii) Pearson correlation. Minimal important difference (MID), minimal important change (MIC) and minimal detectable change (MDC) values were calculated.

Results
114 patients with IIM (median age 60, 60 % female) completed both visits. Changes in PROMIS instruments were significantly different among anchor categories. Patients who reported improvement had a significant improvement in their PROMIS scores with at least medium effect size, while patients who reported worsening and stability did not show a significant change with weak effect size. PROMIS instruments had weak to moderate correlations with MMT, patient and physician global disease activity. MID was approximately 2–3 points for Pain Interference and 3–4 points for Fatigue and Physical Function

forms based on the method used. MIC was approximately 4–5 for improvement of all the instruments, while MDC was 1.7–2 points for Pain Interference and Physical Function and 3.2–3.9 for Fatigue.

Conclusion
This study provides evidence towards the responsiveness of the PROMIS instruments in a large international prospective cohort of adults with IIM supporting their use as PROMs in adult myositis.

Paywall, https://www.sciencedirect.com/science/article/abs/pii/S0049017223001816

 

So it's not sensitive to worsening function. That's not good. In fact that's terrible since worsening is far more significant than improvement. And those:

are fully generic. But always we see attempts to make scales for each individual condition out there, and for variants of conditions, and for different populations of variants of conditions. It's both generic and specific, in all the wrong places for both in a worst of both worlds combination. Kind of like a kitchen that makes every single thing that is part of a plate to order. Preparing 2 orders of pasta with sauce? Make 2 individual sets of boiled pasta, and start 2 sauces from scratch. Consecutively. Service in 4-6 hours for each serving. Want cheese? That'll be, well, depends on when the next cow gives birth. This entire model of doing things makes no sense. It's the least effective most redundant and least economical way of doing anything.

PROMs created by clinicians seem to suffer from the same problems as technical standards, there are often too many of them for no valid reason, except worse in every regard, since they are generally worse than the simplest rating scales, which themselves are rather poor since they're always relative to personal experience and memory.

So they're pretty much all bad, and some are even worse than that. But once someone comes up with their own PROM, they want to push it into becoming adopted, regardless of whether it's any good, because this is what academics are expected to do. It's good for their career if a bad PROM becomes widely adopted, e.g. the terrible Chalder scale. What a terrible system.

But of course this seems expected. Why would clinician-created rating scales for patient-reported outcomes be any good? They don't know what it's like to be a patient. This is as nonsensical as a planned economy where the leaders of the state, almost all middle-aged men, make decisions about how many basic goods each citizen needs, from socks to cheese and soap. What the hell do they know about any of this?