title: At Completion of a Multidisciplinary Treatment Program, Are Psychophysical Variables Associated with a VAS Improvement of 30% or More, a Minimal Clinically Important Difference, or an Absolute VAS Score Improvement of 1.5 cm or More?
abstract: OBJECTIVE
  Objectives were to determine at completion of a multidisciplinary pain program: 1) what percentage of chronic low back pain (CLBP) patients had improved at 30% or more (minimal clinically important difference [MCID]) and by 1.5 cm or more (minimal important change [MIC]) on the visual analog scale (VAS) and 2) whether that improvement is associated with pain matching (PM), pain threshold (PTRE), and pain tolerance (PTOL) improvements.
  
  
  METHODS
  One hundred and six CLBP patients had admission and discharge scores for VAS, PM, PTRE, and PTOL. Improvement was determined by absolute, MCID, and MIC VAS improvement. Logistic regression analysis controlling for age, gender, race, education, psychoactive substance dependence, and depression was utilized to develop models for the dependent variables of improvement of overall VAS; of MCID of 50% or more; and of MIC with PM, PTOL, and PTRE as independent variables.
  
  
  RESULTS
  Thirty-two percent and 35% of the CLBP patients were at MCID and MIC, respectively, at discharge (68% and 65% not at MCID and MIC, respectively), and 54.7% were improved overall. Of the improved patients, 59% were at MCID and 63.7% at MIC. PM was associated with overall VAS improvement, while PTRE and PM were associated with MCID improvement. MIC and 50% or above models could not be estimated.
  
  
  CONCLUSIONS
  The VAS was treated as a ratio scale.
  
  
  CONCLUSIONS
  A significant percentage of CLBP patients were at MCID and at MIC at completion of multidisciplinary treatment. PM was associated with overall VAS improvement, while PTRE and PM were associated with MCID.
authors.affiliation: *University of Miami Miller School of Medicine, Miami, Florida; Departments of Psychiatry and Behavioral Sciences; Neurological Surgery; Department of Anesthesiology at University of Miami Miller School of Medicine, Miami, Florida; Department of Psychiatry, Miami VA Medical Center, Miami, Florida; The Rosomoff Comprehensive Pain Center, Miami, Florida; The Rosomoff Comprehensive Pain Center of Miami Jewish Health Systems, Miami, Florida; d.fishbain@miami.edu.
authors.forename: David A
authors.initials: DA
authors.lastname: Fishbain
authors.affiliation: Wells Fargo Bank, Charlotte, North Carolina;
authors.forename: Jinrun
authors.initials: J
authors.lastname: Gao
authors.affiliation: *University of Miami Miller School of Medicine, Miami, Florida; Departments of Psychiatry and Behavioral Sciences;
authors.forename: John E
authors.initials: JE
authors.lastname: Lewis
authors.affiliation: *University of Miami Miller School of Medicine, Miami, Florida; Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Florida, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000628:therapy; D008297:Male; D008875:Middle Aged; D000071081:Minimal Clinically Important Difference; D010147:Pain Measurement / Q000592:standards*; D017288:Pain Threshold; D055815:Young Adult
keywords: Chronic Low Back Pain; Minimal Clinically Important Difference; Pain Matching; Pain Threshold; Pain Tolerance; Psychophysical Testing