Effects of a novel differential diagnosis aid for managing patients with unexplained fatigue in primary care: a prospective..., 2025, Battegay et al

[rvallee]

Effects of a novel differential diagnosis aid for managing patients with unexplained fatigue in primary care: a prospective randomized, controlled, open and multicenter study in primary care
Open access: https://link.springer.com/article/10.1186/s12875-025-02873-3


Abstract

Aims of the study
Unexplained fatigue is a common reason for encounters in primary care. However, currently no aid orients physicians in detecting its potential causes. The aim of this study was to evaluate whether the novel Fatigue Differential Diagnostic Aid (FDDA) supported clinicians in better managing unexplained fatigue.

Methods
This was a prospective, cluster-randomized, controlled, open, and multicenter study comparing the use of the FDDA vs usual care in patients with unexplained fatigue as the main reason for encounter. The primary endpoint was difference in Patient Global Impression of Change (PGIC) between groups at 3 months. Among pre-defined secondary endpoints were: Difference in change of PGIC between groups at 6 months; percentage of patients with fatigue reduction; mean reduction in fatigue; clinician’s confidence in diagnosis; patient satisfaction with quality of care (diagnostic process and treatment); number of clinician-reported visits; number of referrals to specialists; and time until final diagnosis.

Results
112 primary care practitioners (PCPs) recruited in Switzerland between 2017 to 2020 were randomly cluster-assigned to the FDDA = 57 or usual care = 55 arm. Of these, 15 (FDDA) and 22 (usual care) PCPs recruited 93 patients (FDDA: n = 40, usual care: n = 53). The achieved sample size was less than planned. There was no difference in PGIC at 3 months between groups (D = 0.06, 95%-CI: -0.41 – -0.53, p = 0.802). Among secondary endpoints, no significant differences occurred in PGIC at 6 months, nor in fatigue reduction. However, in the FDDA group, more patients reported less fatigue at 3 or 6 months (D = 18.9%, 95%-CI: -33.6 – -4.3%, p = 0.011), and increased satisfaction with treatment management at 1 month (FDDA 56.8% vs usual care 25.0%, p = 0.004) and 3 months (FDDA 64.9% vs usual care 31.0%, p = 0.003); the FDDA was also associated with higher total number of visits (median 4.0 vs 3.0, p < 0.001).

Conclusions
In this pilot study, the FDDA, a structured diagnostic aid for guiding PCPs in identifying the causes of unexplained fatigue in their patients, was not able to show a global improvement in patient outcomes despite improvements in fatigue and satisfaction with care. The evaluation of fatigue in larger-scale studies is warranted.

 

[rvallee]

Best I can find, they took a few questions from a few of the useless questionnaires and gave it a name:

The FDDA includes validated questions from well-published tests, such as the PHQ-2, PHQ-5 and GAD-7, and other clinically relevant questions to assess fatigue

So it's a "new" tool in a similar sense as taking two hammers, cutting them in halves, and gluing them together is new, compared to the original hammers.

The conclusions may as well be a "and here's why medicine is unable to make any progress here":

This pilot study indicates that the FDDA, a structured diagnostic aid designed to assist primary care physicians in the differential diagnosis of unexplained fatigue, did not lead to a global improvement in patient-reported outcomes. However, it improved patients’ perception of their level of fatigue and satisfaction with care. Larger-scale studies are warranted to evaluate whether multidisciplinary aids like the FDDA can support PCPs in identifying the causes of unexplained fatigue in their patients.

When you take into account just how extremely low the bar is, how simply showing up will basically get you a 3/5 rating, and being courteous and seemingly understanding will get you a 4/5 from most people, this is just entirely pointless. Improving patients' perception is not a useful anything, and while satisfaction with care should be a laudable goal, its evaluation is never reliable.

Seriously, it's very obvious how most medical professionals have no idea just how low the bar is for patient satisfaction, especially with a patient group that is used to awful experiences with health care, but even with the general public. If food critics graded on the same curve, any military mess hall where the food is actually edible would get a Michelin star as long as it doesn't smell too much of grease.

 

[rvallee]

Yet again, though, the critical flaw where a group of people develop something, and test it all on their own. This is now a serious way of doing anything. Testing something, quality assurance, is not some sideshow, it's a whole discipline of its own and they're not respecting any of this. This is as asinine as having Olympic divers rate their own dives. Oh, you got a 10? Daaaamn!

As if someone would develop some test, instrument or treatment and test it rigorously enough to find that it's not useful, when they obviously developed it so that it would be useful.

 

[Hutan]

Supplementary Material 1 has the diagnostic aid. I don't actually mind the idea of this. I'm keen on checklists in medicine, because people, even doctors, are fallible. Yes, you might get the brilliant doctor who doesn't need a checklist and who might be able to get through the evaluation quicker without it. But, you might just get the really poor doctor who got into med school because their family was rich enough to pay whoever had to be paid. You might not even get a doctor, because there aren't enough of them. With the checklist, at least everyone has a bit of a chance of getting some level of care and some appropriate tests.

And, I don't actually mind most of the contents of the diagnostic aid. It includes quite a bit more than just the surveys of mood disorders.

Another reason I like checklists is that they are transparent. We can see what doctors are looking for. For example, unsurprisingly, there is nothing there asking anything that might find PEM.

Patient exclusion criteria were: pre-existing anaemia; treatment received for fatigue by a physician within 3 months prior to the baseline visit; previously diagnosed disease that could have induced the fatigue symptoms (e.g. chronic heart or kidney failure; inflammatory bowel disease; rheumatoid arthritis, multiple sclerosis, cancer); known use of medications could induce fatigue-like symptoms, such as antihistamines, antidepressants, benzodiazepines, hypnotics, anxiolytics, opioid formulations (this list is non-exhaustive and medical judgement could be applied); participating in, or having completed another clinical trial < 30 days prior to study entry.

Rather than all these things being exclusionary criteria for the study, surely you would want to include these people as you evaluated a Fatigue Differential Diagnostic Aid?

I think the intention is that the doctor takes you through the diagnostic aid - and I can imagine that process being and feeling useful. (Although, I suspect what would actually happen in practice is that the receptionist hands you the survey and you fill it out as best you can, in order to save consultation time.)

 

[rvallee]

The idea is definitely something worth achieving, but taking a few questions from the PHQ and the GAD really don't add up to even a basic understanding of what fatigue means.

If anything, all this shows that medicine still has exactly zero new knowledge about the medical concept of fatigue since at least the time of Caesar, whichever one prefers this to refer to, makes no difference.