The Fatigue Severity Scale (FSS) is a clinically validated 9-question assessment used in multiple sclerosis research worldwide. It takes less than 2 minutes.
You'll receive your personal score and see how it compares to other patients — based on published clinical data.
This assessment is for informational purposes only and does not constitute medical advice or diagnosis. Consult your physician with any health concerns.
Base your answers on how you have felt during the past week.
In the PhoCIS clinical trial, participants who received NB-UVB phototherapy showed a reduction in fatigue scores at 6 months that met the minimally important difference — the threshold researchers use to determine whether a change is clinically meaningful, not just a statistical fluctuation. The control group showed the opposite trend over the same period.
The PhoCIS trial (Hart et al., 2018) was a randomised controlled study of narrowband UVB phototherapy in patients with Clinically Isolated Syndrome (CIS) — an early-stage demyelinating condition and recognised precursor to MS.
Fatigue at 6 months: The phototherapy group's FSS score dropped from a median of 3.7 to 2.8 — a change of 0.9 points. The accepted minimally important difference (MID) for the FSS is 0.45 points, meaning the phototherapy group's improvement was twice the threshold for clinical relevance.
We're building a database of fatigue data from people living with autoimmune conditions to better understand how phototherapy helps. Your data is kept private and used only in aggregate.
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🔒 Your responses are anonymous and never sold or shared with third parties. Initials, if provided, are used only to distinguish repeat submissions.
Our team has helped patients with MS, long COVID, and other autoimmune conditions reduce fatigue and reclaim their quality of life. A 10-minute discovery call costs you nothing.