Thread by @PutrinoLab

Short 🧵on symptom measurement in #LongCovid / #MECFS and other chronic illnesses. We need to do better. Many of the symptoms that we're trying to track don't have a physical biomarker, and while patient-reported outcomes (PROs) are helpful, then need to be far more (1/n)

rigorously developed. Let's pick on fatigue as a #LongCovid symptom, because it is incredibly disabling for most folks with LC and it is not well characterized. To measure fatigue, my team uses the Fatigue Severity Scale. Why? Because it is well-validated and allows us to (2/n)

reliably track change in response to interventions. Is it perfect? Far, far from it. The FSS gives us a reliable, but basic understanding of fatigue severity and how it is impacting daily life. What it doesn't do, however, is help us to differentiate different causes and (3/n)

subtypes of fatigue. This is a problem, because this means that we can't better understand if certain interventions are helping certain types of fatigue and not others. We need to put resources into developing better instruments that identify and measure more nuanced (4/n)

variables that are representative of the experiences of people with #LongCovid. For instance, all fatigue is not made equal: let's explore three types of "fatigue" (there are many more):
1) Fatigue from REM sleep disruption: You feel sleepy, foggy, emotionally labile
(5/n)

2) Fatigue from #dysautonomia: Often will feel like someone literally flipped a switch and now you're fighting to remain conscious.
3) Fatigue from oxidative stress/mitochondrial dysfunction: You feel like you're trapped in...acidic jelly - hard to move, sluggish, burning (6/n)

All three of these fatigue types exist in #LongCovid (and #MECFS, and other chronic illnesses), but because of decades of research that has failed to center patient voices and engage in community co-design, we have not developed instruments to investigate these things. (7/n)

Why does this matter? Because if you don't have a sensitive instrument to measure a symptom, it leads to challenges in understanding the effect an intervention is having: autonomic rehab won't influence your fatigue if your fatigue is from mitochondrial dysfunction, but we (8/n)

don't have an instrument to differentiate the two, so instead we have "responders" and "non-responders" in clinical trials where the effect sizes don't reach statistical significance because we weren't characterizing this nebulous symptom of "fatigue" precisely enough in (9/n)

the first place. So where do we go from here? Let's start developing detailed PROs for these "hard to characterize" #LongCovid symptoms! @NIH: if you funded groups like @patientled and @itsbodypolitic to hire psychometricians, they could activate their community and do (10/n)

this in a heartbeat. STOP funding establishment researchers that have consistently failed to involve the community they are supposed to be SERVING (not heartlessly studying) in their research. Until this work gets done, well, it's very hard to treat what we can't measure (end)