Back patients' perception of their pain appears to change very little

New research uses a new method to help back pain patients describe their pain trajectory and reveals that patients' pain patterns change only slightly over time. Chiropractors can benefit from using the method to identify pain patterns in their patients and the knowledge provided about changes in pain patterns when treating their patients, because the patient's identification of his pain pattern via the new method can be used to support communication between the patient and the practitioner during the consultation.

Studies have shown that low back pain (LBP) follows different pain trajectories, and patients with LBP seem to recognize the trajectory of their own back pain. This enables chiropractors to ask their patients to describe their pain trajectory using the new method, where the patient is asked to select one out of eight different illustrations that best describes the patient's pain pattern. The eight illustrations are collectively called "self-reported visual pain trajectories" (SRVT) and are shown in the paper in the link below.

For many back patients, their pain trajectory appears to be stable over time, but this is a presumption for which there is only scant evidence. This has led a group of researchers to investigate the temporal stability of pain trajectories over a year in relation to pain intensity and course patterns and the connection between shifts between trajectories and changes in pain and functional impairment. The basis for the study was data from the ChiCo cohort (n=1323) and the GLA:D Back cohort (n=1135).

Approximately 30% remained in the same pain trajectory, and those patients who switched trajectories mainly switched to similar trajectories that differed on only one subscale. A shift to less or more intense trajectories was associated with expected changes over time. Despite distinctly different identified pain trajectories, participants reported relatively stable LBP phenotypes, but with the potential for change.

The participants identified their own pain trajectory among eight pain trajectories and were asked about the trajectory of the patient's LBP in the past year at the beginning of the study and at follow-up after 12 months. The trajectories were described using two subscales: intensity and pattern. Temporal stability was quantified by "stability odds ratios" (ORs), which show the probability of a patient experiencing the same pain trajectory after 12 months as at baseline, and by "preference ORs," which show the probability that a patient will choose a specific alternative trajectory at follow-up. Both ORs compare the observed proportion of likely change in the course. Finally, the researchers examined correlations between switching to another trajectory and changes in the outcome of the treatment.

Lead researcher Casper Glissmann Nim received the NCMIC New Investigator Award at the WFC World Congress in 2021 for his paper detailing the study.

Nim CG, Kongsted A, Downie A, Vach W. The temporal stability of self-reported visual back pain trajectories. Journal of Pain. 2022