Prospective Back Pain Trajectories or Retrospective Recall - Which Tells Us Most about the Patient?

In patients with low back pain, a visually identified retrospective pain trajectory often mismatches with a trajectory derived from prospective repeated measures. To gain insight into the clinical relevance of the two trajectory types, we investigated which showed a higher association with clinical outcomes. Participants were 724 adults seeking care for low back pain in Danish chiropractic primary care. They answered weekly SMSs on pain intensity and frequency over 52 weeks, which we translated into eight trajectory classes. After 52 weeks, participants selected a retrospective visual pain trajectory from the same eight trajectory classes. Clinical outcomes included disability, back/leg pain intensity, back beliefs, and work ability. The patient-selected pain trajectory classes were more strongly associated with clinical outcomes than the SMS trajectory classes at baseline, at follow-up, and with outcome changes between baseline and follow-up. This held across all five clinical outcomes, with the strongest associations observed at week 52 and the weakest at baseline. Patients’ retrospective assessment of their low back pain is more strongly associated with their clinical status than their prospective assessments translated into trajectory classes. This suggests that retrospective assessments of pain trajectories may provide valuable information not captured by prospective assessments. Researchers collecting prospective pain data should know that the captured pain trajectories are not strongly reflected in patients’ perceptions of clinical status. Patients’ retrospective assessments seem to offer an interpretation of their pain course that is likely more clinically relevant in understanding the perceived impact of their condition than trajectories based on repeated measures.PerspectiveProspective pain data inadequately reflect patients’ clinical status. Retrospective assessments provide a more clinically valuable understanding of the impact of their condition.