Estimation of minimum clinically important difference for pain in fibromyalgia.

Abstract

OBJECTIVE:

To estimate the minimum clinically important difference (MCID) for several pain measures obtained from the Brief Pain Inventory (BPI) for patients with fibromyalgia.

METHODS:

Data were pooled across 12-week treatment periods from 4 randomized, double-blind, placebo-controlled studies designed to evaluate the safety and efficacy of duloxetine for the treatment of fibromyalgia. Each study enrolled subjects with American College of Rheumatology--defined fibromyalgia who presented with moderate to severe pain. The MCIDs for the BPI average pain item score and the BPI severity score (the mean of the BPI pain scale values: right now, average, least, and worst) were estimated by anchoring against the Patient's Global Impressions of Improvement scale.

RESULTS:

The anchor-based MCIDs for the BPI average pain item and severity scores were 2.1 and 2.2 points, respectively. These MCIDs correspond to 32.3% and 34.2% reductions from baseline in scores.

CONCLUSION:

In these analyses, the MCIDs for several pain measures obtained from the BPI were similar (∼2 points) and corresponded to a 30-35% improvement from baseline to end point. These findings may be beneficial for use in designing clinical trials in which the BPI is used to evaluate improvements in pain severity.

• Authors: Philip J Mease, Michael Spaeth, Daniel J Clauw, Lesley M Arnold, Laurence A Bradley, I Jon Russell, Daniel K Kajdasz, Daniel J Walker, Amy S Chappell
• Journal: Arthritis care & research (Arthritis Care Res (Hoboken)) Vol. 63 Issue 6 Pg. 821-6 (Jun 2011) ISSN: 2151-4658 [Electronic] United States
• PMID: 21312349 (Publication Type: Comparative Study, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2011 by the American College of Rheumatology.

Chemical References

• Thiophenes
• Duloxetine Hydrochloride

Topics

• Adult
• Double-Blind Method
• Duloxetine Hydrochloride
• Female
• Fibromyalgia (complications, diagnosis, drug therapy)
• Humans
• Male
• Middle Aged
• Pain (complications, diagnosis, drug therapy)
• Pain Measurement (methods, standards)
• Severity of Illness Index
• Thiophenes (therapeutic use)