The STarT Back Tool for people with chronic low back pain – strengths and limitations

The STarT Back Tool (SBT)[1] is a 9-item, self-report questionnaire that includes treatment modifiable domains (spread of pain, disability, and psychological factors).[2] It subgroups patients with non-specific low back pain (LBP) into low, medium, and high risk of future disability with the purpose of matching each subgroup to a care pathway. The SBT was developed in the UK in a primary care, general practice setting where participants had LBP of ‘variable’ episode duration (i.e. acute/sub-acute/chronic).[2] The tool has become popular in both research and clinical settings.

The SBT’s appeal is obvious. It is short, easy to complete (most responses yes/no format), and quick to score. It can be easily implemented into busy clinical practice by health care practitioners. The care pathway for each subgroup is well-defined. The low risk subgroup is appropriate for self-management advice/education, reassurance, analgesics, and need re-consult only if necessary. The medium risk subgroup is appropriate for referral to physiotherapy. The high risk subgroup should be referred to an appropriately skilled physiotherapist to address psychological and physical obstacles to recovery.

Previous studies have reported that the SBT’s performance is influenced by clinical setting, cultural context, LBP episode duration, and the outcome measured. With this in mind, could this short, simple tool be used to predict risk of poor outcome in people exclusively with chronic LBP given the complex, multidimensional nature of chronic LBP? We aimed to answer this question in our study which was recently published in the Journal of Physiotherapy.[3]

Our study

We included 290 people with chronic, non-specific LBP of ≥ 3 months duration with an average baseline pain intensity of ≥ 2 on an 11-point Numerical Rating Scale and LBP-related disability of ≥ 5 on the Roland Morris Disability Scale (RMDQ). Participants were recruited from the general community as well as private physiotherapy and pain management clinics.

The SBT can be used as a substitute for longer questionnaires

Participants completed the SBT and a battery of psychological questionnaires. As with previous research, our study found that higher SBT categorisation was associated with significantly greater pain intensity, disability, and negative psychological affect and cognitions (including depression, anxiety, stress, fear avoidance beliefs, catastrophising, and perceived risk of pain persistence). Unique to our study, we were able to demonstrate that higher SBT categorisation was associated with significantly lower self-efficacy and chronic pain acceptance. The results indicated that the SBT has value as a substitute for the administration of multiple, full-length, unidimensional questionnaires for first-line screening in people with chronic LBP.

The SBT can assist with predicting poorer recovery with respect to disability

One year follow-up data were available for 91% of the participants. Our study found the SBT had moderate predictive and acceptable discriminative ability for future disability. More specifically, the results indicated that participants in the medium risk subgroup and high risk subgroup respectively had a 130% and 186% increased risk of being disabled (≤ 7 on the RMDQ) one year later compared to the low risk subgroup. The SBT correctly classified participants as “not recovered” with respect to disability (≤ 7 on the RMDQ) 71% of the time.

The SBT is not so accurate in predicting poorer recovery with respect to pain intensity and self-perceived improvement

Similar to previously published studies, our study found the predictive and discriminative ability of the SBT for pain intensity was poor and the SBT was unable to identify participants who perceived themselves as improved versus not improved on a Global Rating of Change Scale at the one year follow-up. These results were not surprising given that the SBT was originally developed and validated to predict future disability.[2]

Conclusion

Our study showed that the SBT provided an acceptable indication of future disability in people with chronic LBP. However, we as clinicians need to be aware of the strengths and limitations of the tool when using it in clinical practice to provide appropriate advice to our patients. The tool is not 100% accurate in determining future disability risk. Patient relevant outcomes extend beyond self-reported disability and therefore the SBT may not capture risk of poor outcome from every patient’s perspective. We recommend that the SBT be used in conjunction with clinical examination and sound clinical reasoning when making care decisions for our individual patients.

About Michelle Kendell

Michelle is a musculoskeletal physiotherapist and lecturer at the School of Physiotherapy and Exercise Science, Curtin University, Perth, Australia. Originally from Canada where she completed her undergraduate degree in physiotherapy, Michelle has a Master of Manipulative Therapy and Doctor of Clinical Physiotherapy from Curtin University. She teaches in the undergraduate and postgraduate musculoskeletal physiotherapy programs. Michelle’s research interests are in the area of screening for prognostic factors and the multifactorial nature of musculoskeletal pain disorders. Michelle has an interest in the treatment of spinal pain disorders; she works in private practice and as an Advanced Scope Physiotherapist in a Neurosurgery Spinal Assessment Clinic.

References

  1. Keele University. STarT Back. http://www.keele.ac.uk/sbst/startbacktool/. Accessed 14 May, 2018.
  2. Hill J, Dunn K, Lewis M, et al. A primary care back pain screening tool: identifying patient subgroups for initial treatment. Arthritis Rheum. 2008;59(5):632-641.
  3. Kendell M, Beales D, O’Sullivan P, Rabey M, Hill J, Smith A. The predictive ability of the STarT Back Tool was limited in people with chronic low back pain: a prospective cohort study. J Physiother. 2018;64(2):107-113.