Do visual pain trajectories reflect the actual course of low back pain? A longitudinal cohort study

Different trajectories of low back pain (LBP) have been identified prospectively using repeated measures. For these trajectories to inform clinical practice, they must be available in the clinical consultation. Therefore, identified LBP trajectories have been translated into visual pain trajectories (VPTs) that allow people with LBP, at the time of consult, to reflect upon their pain experience and identify the VPT that best categorizes their pain course. We have limited knowledge regarding the extent to which a chosen VPT reflects the prospectively experienced trajectory. Thus, we explored the distribution of pain intensity and pain pattern characteristics (from prospective pain trajectory data) within the retrospectively chosen VPT classes. We enrolled patients with LBP from Danish chiropractic practice. Using SMS, participants (n = 719) scored their pain weekly on an 11-point numerical rating scale for 52 weeks. At week 52, participants identified 1 of 8 VPTs that reflected their perceived back pain trajectory during the preceding year. We found that the chosen VPTs reflected pain intensity, but that pain patterns (episodic, fluctuating, and persistent) were not systematically recognized, and the experienced course varied substantially amongst participants within the same VPT. The VPTs are related to some aspects of the experienced LBP course but are not a proxy for the SMS-measured trajectories. Reasons for apparent mismatches between the experienced course of LBP and VPT recall warrant further investigation. 

Perspective: Self-reported back pain trajectories reflected pain intensities obtained through weekly SMS tracking over a year, but participants’ recall did not reflect the pain patterns (episodes and fluctuations) discovered prospectively. Clinicians can use self-reported pain trajectories to facilitate a dialog about pain experience, but not as a proxy for prospective measures.