text: Statistical analysis 
  All data analyses were preformed using SPSS Version 22.0 
  (IBM Corp., Armonk, NY). We developed models to sep- 
  arately predict over the course of the entire follow-up 
  period: 1) the dichotomous outcome of no healthcare 
  utilization versus any healthcare utilization and 2) the 
  utilization of specific services. We decided to develop sep- 
  arate models since each outcome predicted by these 
  models might have unique future policy implications. For 
  instance, those who utilize no additional services might 
  represent a “low risk” group for which physical therapy 
  alone might be particularly appropriate. Predicting use of 
  specific services would inform policy where reduction of 
  specific services is a high priority, such as utilization of 
  opioids or unnecessary use of emergency room services. 
  
  All prediction models used the following hierarchical 
  design, which is similar to prior analyses in this cohort 
  [20, 21]: 
  
  Healthcare utilization outcomes 
  Self-reported health care utilization was assessed at 6- and 
  12-months following initial evaluation by online assessment. 
  Questions were derived from previous population-based 
  studies involving musculoskeletal pain that have used survey 
  [22, 23]. Study 
  methods 