A few caveats need to be mentioned at the outset. The STarT Back Tool was developed for use in people attending primary care (e.g., their GP or physiotherapist) for treatment. The people in this study, instead, most were not actively seeking treatment at the time of enrolment (although lots had sought treatment or went on to seek treatment during the year of followup). Also, the participants already had CLBP so the duration of time they'd had the pain was quite variable.
The STarT Back Tool categorised the participants into low-, medium- and high-risk subgroups at baseline. Those with higher STarT Back Tool risk categorisation had significantly greater pain intensity, greater disability, higher scores on negative psychological constructs, and lower scores on positive psychological constructs at baseline. This is probably not surprising, given that these constructs are what the tool measures.
The study also looked at the STarT Back Tool's ability to predict pain, disability and perceived change at 1 year. While the Tool provided an acceptable indication of future disability in this population, it performed poorly with respect to pain and global perceived change at the 1-year follow-up.