What scoring system is used for assessing and managing fibromyalgia?

Fibromyalgia Scoring Systems

The American College of Rheumatology (ACR) 1990 classification criteria and the 2010/2016 revised diagnostic criteria are the primary scoring systems used for fibromyalgia assessment, with the Fibromyalgia Impact Questionnaire (FIQ) serving as the standard outcome measure for evaluating disease severity and treatment response. 1

Diagnostic Criteria Systems

ACR 1990 Classification Criteria

• The original ACR 1990 criteria require widespread pain for at least 3 months plus pain at 11 or more of 18 specific tender point sites. 1, 2, 3
• This tender point examination involves applying approximately 4 kg of pressure to 18 bilateral anatomical sites and documenting pain response. 1
• These criteria remain the most commonly used in clinical and therapeutic research trials. 1

ACR 2010/2016 Revised Criteria

• The newer ACR criteria eliminate the tender point examination requirement and instead incorporate a Widespread Pain Index (WPI) and Symptom Severity Scale (SSS). 2, 4
• The WPI assesses the number of painful body regions (0-19 scale). 4
• The SSS evaluates fatigue, nonrestorative sleep, and cognitive symptoms on a 0-3 scale for each domain, plus the extent of somatic symptoms (total score 0-12). 4
• Diagnosis requires WPI ≥7 and SSS ≥5, OR WPI 4-6 and SSS ≥9, with symptoms present for at least 3 months. 4

Outcome Measurement Tools

Fibromyalgia Impact Questionnaire (FIQ)

• The FIQ is the primary validated instrument for assessing functional impairment and treatment response in fibromyalgia, measuring physical function, work status, depression, anxiety, morning tiredness, pain, stiffness, fatigue, and well-being. 1
• The FIQ total score ranges from 0-100, with higher scores indicating greater functional impairment. 1
• A 5-point increase from baseline on the FIQ total score is considered clinically meaningful worsening in clinical trials. 3
• The FIQ is specifically recommended by EULAR guidelines as the standard measure of function in fibromyalgia research. 1

Visual Analog Scale (VAS) for Pain

• Pain intensity measured by VAS (0-100 mm scale) or numeric rating scale (0-10) is the primary pain outcome measure in fibromyalgia trials. 1
• A 30% reduction in pain score from baseline is considered a clinically meaningful response. 3, 5
• A 50% reduction in pain score represents a robust treatment response. 3, 5

Patient Global Impression of Change (PGIC)

• The PGIC assesses overall improvement from the patient's perspective using a 7-point scale ranging from "very much improved" to "very much worse." 3, 5
• Ratings of "much improved" or "very much improved" are considered positive treatment responses in clinical trials. 3, 5

Rapid Screening Tools

Fibromyalgia Rapid Screening Tool

• This brief screening questionnaire helps identify patients who may have fibromyalgia among those presenting with chronic widespread pain. 4
• The tool is designed for use in primary care settings to facilitate early recognition. 4

FIBRO Problem Scale

• The FIBRO mnemonic system provides rapid symptom quantitation using 0-10 verbal scales for: Fatigue, Insomnia (nonrestorative sleep), Brain fog (cognitive dysfunction), Rigidity (stiffness), and Overall pain. 6
• Each symptom is rated 0-10, allowing quick assessment of symptom severity and treatment response. 6
• The companion FIBRO Change Scale measures response to treatment using the same domains. 6

Critical Assessment Considerations

• The ACR 1990 criteria with tender point examination remain the gold standard for research enrollment, while the 2010/2016 criteria are more practical for clinical diagnosis. 1, 2, 4
• The FIQ and pain VAS are the two outcome measures that must be reported in fibromyalgia clinical trials to allow meaningful comparison between studies. 1
• Comprehensive assessment must evaluate pain intensity, functional limitations, sleep quality, fatigue severity, cognitive symptoms, and psychosocial factors including depression and anxiety. 2, 7
• Avoid extensive laboratory testing and imaging, as fibromyalgia is a clinical diagnosis based on symptom patterns rather than laboratory abnormalities. 2, 4, 8