Comparison of sleep structure and psychometric profiles in patients with fibromyalgia, osteoarthritis and healthy controls
Fibromyalgia syndrome (FMS) is a chronic condition characterised by widespread musculoskeletal pain, fatigue, non‐restorative sleep (NRS), morning stiffness and cognitive debilitation (Smythe and Moldofsky, 1977). Diagnostic criteria, set by the American College of Rheumatology (1990), include widespread pain in the four quadrants of the body in combination with tenderness at 11 of 18 defined tender point sites (Wolfe et al., 1990). More recently proposed criteria, which produce a widespread pain index and symptom severity score, eliminate the need for tender point examination (Wolfe et al., 2010). FMS affects between 0.5 and 5% of the general population (Branco et al., 2010; White and Harth, 2001), with the majority of sufferers being female (Yunus, 2001) and older (Wolfe et al., 1995). The diagnosis and treatment options for FMS are associated with significant societal and health care costs (Hughes et al., 2006). While the aetiology of FMS remains largely unknown (Hayes et al., 2010), the syndrome has been associated with a distinctive psychological profile characterised by elevated levels of anxiety, depressive symptoms, poor subjective sleep quality and fatigue (Kurtze et al., 1998; Shuster et al., 2009). However, few studies have simultaneously examined sleep and psychometric status in the same participants.