Related Experiment Video
Updated: Jun 24, 2026
08:33
A Randomized, Sham-Controlled Trial of Cranial Electrical Stimulation for Fibromyalgia Pain and Physical Function, Using Brain Imaging Biomarkers
Published on: January 5, 2024
Minimal clinically important difference in the fibromyalgia impact questionnaire.
Robert M Bennett1, Andrew G Bushmakin, Joseph C Cappelleri
1Oregon Health and Science University, Portland, OR, USA.
The Journal of Rheumatology
|April 17, 2009
Summary
A 14% change in the Fibromyalgia Impact Questionnaire (FIQ) total score signifies a clinically important difference for fibromyalgia patients. This research also establishes new FIQ severity categories for better clinical interpretation.
Area of Science:
- Rheumatology
- Clinical Measurement
- Pain Management
Background:
- The Fibromyalgia Impact Questionnaire (FIQ) assesses fibromyalgia (FM) impact.
- Determining a clinically meaningful change in FIQ scores is crucial for evaluating treatment effectiveness.
Purpose of the Study:
- Estimate the minimal clinically important difference (MCID) for the FIQ.
- Propose severity categories for the FIQ.
Main Methods:
- Modeled data from 3 placebo-controlled pregabalin trials (300-600 mg/day) in FM patients.
- Used Patient Global Impression of Change and established pain cutpoints as anchors.
Main Results:
- A total of 2228 patients (mean age 49, 93% women) with a mean baseline FIQ of 62 were analyzed.
- The estimated MCID for the FIQ total score was 14% (95% CI: 13-15).
- FIQ severity categories were defined as mild (0-<39), moderate (39-<59), and severe (>=59).
Conclusions:
- A 14% change in FIQ total score is clinically relevant for fibromyalgia.
- These findings enhance the clinical utility of the FIQ in research and patient care.
