Patient-Reported Outcomes: A New Paradigm for Evaluating Fibromyalgia
Self-report measures capture the complex nature of this debilitating, chronic condition.
Patient-reported outcomes (PROs) are increasingly gaining traction in the medical world as a highly effective option for capturing the impact of chronic illness and gauging treatment response.
In a review published in the March issue of Rheumatic Disease Clinics of North America, 2 researchers from the University of Michigan in Ann Arbor reviewed the role of PROs in the diagnosis and management of fibromyalgia, an incurable rheumatic disease often characterized by multiple nonspecific symptoms.1
"Unlike symptoms that can be directly observed, such as a broken bone, rash, or vomiting, the symptoms of fibromyalgia are covertly experienced [and] clinicians must rely on high-quality PROs to make assessments within each of the [disease-related] domains,” David A. Williams, PhD, president-elect of the American Pain Society, explained to Clinical Pain Advisor.
An estimated 5 million US adults, many of them women, suffer from fibromyalgia.2 The disease has no cure, and no clear biomarkers are available to guide its management.
"Until there is a cure for fibromyalgia, treatment will be focused on managing symptoms and improving [patient] functioning and quality of life — [and] the only way to know whether our treatments are effective is to ask the patients," Anna L. Kratz, PhD told Clinical Pain Advisor.
Pain is Not the Whole Story
While widespread pain is the primary characteristic of fibromyalgia, evaluations limited to pain intensity fail to tell the whole story, Dr Williams said.
"If only pain intensity is assessed, you miss a lot of valuable information about the pain, such as its distribution, emotional impact, functional impact, and other forms of suffering that are clinically relevant," Dr Williams noted.
Comparing the experience of pain with that of music, Dr Williams said, "I doubt you would ask someone to rate the intensity of a symphony on a scale of 0 to 10 and feel satisfied that you now understand the musical score."
The researchers emphasize that fibromyalgia assessments should cover 6 domains: pain, comorbidities, affective vulnerability (emotional response), beliefs and attitudes, behavior, and environmental/social factors.2
Dr Kratz stressed the need for clinicians to remember that the burden of fibromyalgia symptoms is complex. “For some patients, pain may not even be the most bothersome symptom,” she observed.
Treating one symptom can also exacerbate others, Dr Kratz warned. "Many treatments for pain may cause fatigue, "fibro-fog,” or sleep problems to get worse. This underscores the need for clinicians to assess the full spectrum of symptoms and multiple functional domains that are affected in fibromyalgia," Dr Kratz said.
New PRO Measures for Fatigue, Cognitive Effects
Fatigue is a common symptom of fibromyalgia that, like pain, has multiple dimensions requiring comprehensive assessment. To this end, the authors and colleagues at the University of Michigan developed a new tool: the Patient-Reported Outcomes Measurement System (PROMIS) FatigueFM Profile.3 The instrument measures 16 PROs spanning 4 aspects of fatigue.