text: Diagnostic tests or imaging 
  Comorbidity index score (OR = 1.35–1.45, p < 0.05), 
  baseline disability (OR = 2.25–2.66, p < 0.001), and base- 
  line to 4-week change in pain intensity (OR = 3.04–3.05, 
  p = 0.01) were significant predictors of diagnostic test or 
  imaging utilization. Among these, baseline disability was 
  the strongest predictor. In these models, higher comor- 
  bidity index, higher baseline disability and worsening 
  pain were associated with higher odds of utilization. 
  Together, these variables explained approximately 30% 
  of the variance in utilization. 
  
  Emergency room 
  Models for emergency room use had the highest pseudo-R2 
  values of any individual service (0.48–0.50), but also had 
  the largest number of predictors (8–9). Agreement between 
  complete case and weighted models was moderate. The 
  models converged on the following predictors: age (OR = 
  0.91–0.94, p < 0.05), insurance (OR = 8.99–13.15, p < 0.05), 
  baseline disability (OR = 3.33–4.88, p < 0.001), and change 
  in pain (OR = 1.59–1.77, p < 0.05). Higher utilization was 
  associated with younger age, other insurance (e.g., self-pay, 