Psychometric Validation of the World Health Organization Disability Assessment Schedule 2.0-12-Item Version in Persons with Fibromyalgia Syndrome

Abstract

Fibromyalgia Syndrome (FMS) is a chronic pain disorder of undetermined cause, characterized by widespread musculoskeletal pain, as well as a range of neurological, psychological, and physical symptoms. FMS affects approximately 2% to 3% of the United States population, and women are approximately 7 to 10 times more likely to have FMS than men (Howard et al., 2010; Goldenberg, 1999; Weir et al., 2006). The primary clinical symptoms associated with FMS include diffuse pain, fatigue, stiffness, and sleep disturbances. FMS is also associated with a number of secondary symptoms and health conditions, including dizziness, neurological disturbances (e.g., numbness, tingling, and burning feelings in the extremities), headaches, cognitive impairments (e.g., memory disturbances, disruptions in attention and concentration, difficulty with executive functioning), irritable bowel syndrome (IBS), Raynaud's syndrome, restless leg syndrome (RLS), and temporomandibular joint disorder (TMJ; Ambrose, Gracely, & Glass, 2012; Bennett, Jones, Turk, Russell, & Matallana, 2007). The presence of co-existing psychiatric symptoms is also common in persons with FMS. Research indicates that between 30% and 45% of persons with FMS experience symptoms of depression, anxiety, and/or heightened stress (Kurtze, Gundersen, & Sveback, 1998). Moreover, individuals with FMS experience greater levels of psychiatric symptoms than individuals with other types of pain (Gormsen, Rosenberg, Bach, & Jensen, 2010). While individuals with FMS at times experience symptom remission, more common are periods known as flare, which are characterized by an exacerbation of pain and other symptoms. Not surprisingly, individuals with FMS experience markedly impaired levels of functioning in their daily lives, more significant barriers to community participation (e.g., employment, social activity, and leisure), and thus, lower quality of life and life satisfaction (Henriksson & Liedberg, 2000; Liedberg & Henriksson, 2002). One study found that middle-age women with FMS possessed similar functioning levels to those of sedentary women approximately 25 years older (Kingsley et al., 2003). In a review of 37 studies, Hoffman and Dukes (2008) found that in comparison with the general population, persons with FMS were significantly more impaired in various functional domains, including physical functioning, role functioning, and social functioning. The study further reported that persons with FMS had higher levels of pain, lower levels of vitality, and lower levels of general health. Furthermore, compared to the general population, individuals with FMS have higher rates of work disability, as well as more difficulty performing activities of daily living (ADLs; Penrod et al., 2004; Robinson et al., 2003; White et al., 2008; White, Speechley, Harth, & Ostbye, 1999). Although the physiological symptoms of FMS are indeed profound, these symptoms represent only one component of the FMS experience. The problems associated with FMS are the result of complex interactions between a number of biopsychosocial factors, including health condition factors, personal/ psychological factors, and socioenvironmental factors (Abeles, Pillinger, Solitar, & Abeles, 2007; Loevinger, Shirtcliff, Muller, Alonso, & Coe, 2012); thus, no single factor alone can be used to understand and assess level of disability in persons with FMS. For instance, research suggests that personal/ psychological factors such as self-esteem (Burke, Mathias, & Denson, 2015), self-efficacy (Miro, Martinez, Sanchez, Prados, & Medina ,2011), perceived control (Schuster, McCormack, Riddell, and Toplak, 2009; Skuladottir & Halldorsdottir, 2008), coping skills (Zautra, Hamilton, & Burke, 1999), and emotional stability (Torres et al., 2013) are associated with disability and quality of life outcomes in persons with chronic pain and/or FMS. Furthermore, the role of the social environment in predicting FMS outcomes cannot be overstated. …