Providing Feedback on Previous Pain Scores Did Not Affect Weekly Pain Variability: A Cohort-Nested Randomised Study.

Abstract

BACKGROUND: Spinal pain is one of the leading causes of disability worldwide and repeated symptom monitoring is increasingly used to capture its fluctuating nature. However, repeated pain assessments may be influenced by prior responses, potentially affecting longitudinal patterns of pain reporting. This study examined whether providing feedback on prior pain scores influenced within-person variability in weekly pain intensity ratings and retention over 60 weeks. METHODS: This randomised study evaluating a methodological feature of repeated pain assessment was embedded within a cohort of adults with spinal pain referred to an outpatient hospital clinic. Participants (n = 2448) were randomised 1:1 to weekly pain intensity ratings (0-10 numerical rating scale) either with feedback ('You answered [X] last week') or without feedback. Analyses included participants with ≥ 40% valid responses (n = 1883), of whom 948 received feedback and 935 did not. The primary outcome was within-person variability in pain intensity, quantified using the root mean square of successive differences. Secondary outcomes included additional fluctuation metrics and the number of weeks with missing responses. RESULTS: No meaningful between-group differences were observed for the primary outcome (mean difference -0.04 points [95% confidence interval -0.08 to 0.01]) or secondary outcomes, including retention rates. Sensitivity analyses yielded consistent findings. CONCLUSIONS: Providing participants with feedback on their previous pain score did not meaningfully influence within-person pain variability or retention during 60 weeks of weekly monitoring. These findings aid the interpretation of repeated longitudinal pain assessments by showing that the observed variability was robust to this specific study design. SIGNIFICANCE: This randomised study showed that providing participants with feedback on prior pain scores did not meaningfully alter weekly pain variability or retention during 60 weeks of longitudinal monitoring. These findings contribute to the interpretation of repeated longitudinal pain assessments in spinal pain research and suggest that weekly pain reporting patterns are robust to prior-pain feedback during long-term symptom monitoring.