text: [24–26]. Participants 
  
  pain imaginable) 
  rated their 
  current pain intensity, as well as their best (lowest) and 
  worst 
  the past 24 h. 
  Current, best and worst pain ratings were averaged for 
  purposes of analysis. 
  
  Healthcare utilization predictors 
  We collected potential predictors by self-reported ques- 
  tionnaires at initial evaluation using an online study web- 
  site. Participants were directed back to the study website 
  4 weeks following initial evaluation to again complete 
  questions on pain intensity, disability, and pain-related 
  psychological distress. Change in pain intensity, disability, 
  and pain-related psychological distress from baseline to 
  4 weeks were modeled as treatment response variables 
  and included as potential predictors. 
  
  (highest) pain intensity over 
  
  Region-specific disability 
  Self-reported region-specific disability was assessed with 
  the Neck Disability Index [27, 28], Oswestry Disability 
  Questionnaire [29, 30], Quick Disability of Arm Shoulder 
  and Hand [31] or International Knee Documentation 
  Committee Subjective Knee Form [32] for cervical, low 
  back, shoulder and knee pain, respectively. Region-specific 
  disability measures were z-transformed for purposes of 
  analysis, consistent with our prior work involving multiple 
  anatomical regions [33]. 