In people with medical conditions linked with physical disabilities, Silhouettes Fatigue Scale (SFS) is a brief, easy to administer and understand, and valid measure of fatigue.

This study aimed to assess validity of SFS with English instructions (SFS-EN) in 523 people (mean age = 59.1 years) with chronic pain and physical impairment.

Participants gave response to the online survey which incorporated SFS-EN and another authenticated measure of fatigue (PROMIS short form-4a Fatigue Scale), and estimates of pain catastrophizing and pain intensity.

The outcomes demonstrated robust positive associations between both the measures of fatigue, favoring convergent validity of SFS-EN. Furthermore, magnitude of this connection was considerably more when compared to the link between scores of SFS-EN and estimates of pain intensity and pain catastrophizing, favoring the former's discriminant validity.

SFS-EN is an easy to understand measure, while SFS is a novel single-item measure of general fatigue. The outcomes favored the discriminant and convergent validity of SFS-EN score in adults with chronic pain and physical disabilities.