Preliminary development of a responder index for chronic low back pain.
OBJECTIVE
One of the greatest obstacles to identifying the most effective therapy for chronic low back pain (CLBP) is the lack of standardized outcome measures for assessing treatment effect in clinical trials. The aim of the OMERACT Special Interest Group was to discuss the development and validation of a preliminary responder index in CLBP.


METHODS
Patient data from 5 clinical trials of celecoxib and valdecoxib use in CLBP were used to assess the reliability and validity of multiple items in the outcome domains of pain, functioning, and overall impression of health. Candidate preliminary responder indices were selected on the basis of effect size, high chi-square test values, and a placebo response rate < or = 25%.


RESULTS
Candidate indices comprised improvements in single outcome measures and combinations of improvements and/or avoidance of worsening in multiple measures. The preliminary choice for the responder index was at least 30% improvement in pain, with an improvement of at least 30% in patient global assessment and no worsening in function.


CONCLUSIONS
Further studies are needed to refine a responder index for CLBP trials that is clinically relevant, reliable, and easy to administer for standardizing assessments across clinical trials.
Simon
Lee S
LS
Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02465, USA. lsimon@bidmc.harvard.edu
Evans
Christopher
C
Katz
Nathaniel
N
Bombardier
Claire
C
West
Christine
C
Robbins
Jeffery
J
Copley-Merriman
Catherine
C
Markman
J
J
Coombs
John H
JH
D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D000068579:Celecoxib; D002908:Chronic Disease; D002986:Clinical Trials as Topic; D017144:Focus Groups; D006305:Health Status Indicators; D006801:Humans; D007391:International Cooperation; D007555:Isoxazoles / Q000627:therapeutic use; D017116:Low Back Pain / Q000188:drug therapy* / Q000503:physiopathology / Q000523:psychology; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011720:Pyrazoles / Q000627:therapeutic use; D015203:Reproducibility of Results; D013449:Sulfonamides / Q000627:therapeutic use; D000096926:Benzenesulfonamides
D000894:Anti-Inflammatory Agents, Non-Steroidal; D000068579:Celecoxib; D007555:Isoxazoles; D011720:Pyrazoles; D013449:Sulfonamides; C406224:valdecoxib; D000096926:Benzenesulfonamides