“…Along with chronic widespread musculoskeletal pain and fatigue, poor sleep quality is considered a central symptom of FM (Arnold et al, 2019; Rudin, 2019), with an estimated prevalence of 65–99%; only 11.2% of people with FM do not demonstrate sleep problems (Andrade et al, 2018; Theadom, Cropley, & Humphrey, 2007). Poor sleep quality is also one of the principal causes behind exacerbation of FM symptoms (Andrade et al, 2018; Choy, 2015; Huang, Huang, Fan, Chen, & Tsai, 2019). Evidence demonstrates that poor sleep quality aggravates pain (Certal & Domingues, 2018; Choy, 2015), fatigue and cognitive problems (Choy, 2015) and has a negative impact on quality of life and social functionality in people with FM (Börsbo, Liedberg, & Björk, 2015).…”