Validating the Minimal Clinically Important Difference for the Edmonton Symptom Assessment Scale (ESAS) Total Symptom Distress Score (TSDS).

BACKGROUND

The Edmonton Symptom Assessment Scale (ESAS) Total Symptom Distress Score (TSDS) is widely used in palliative care to assess symptom burden. While minimal clinically important difference (MCID) values have been established by Hui and colleagues' validation across different patient populations is essential.

OBJECTIVE

To validate the MCID values for the ESAS TSDS using data from two randomized controlled trials of medicinal cannabis in advanced cancer.

METHODS

We analyzed data from 186 patients with incurable cancer. The Patient Global Impression (PGI) scale served as the anchor, with "minimally improved" defining improvement and "minimally worse" defining deterioration. We employed anchor-based methods (sensitivity-specificity approach and within-patient change approach) and distribution-based methods (0.3 and 0.5 standard deviations) to validate MCID values.

RESULTS

For improvement, the within-patient change method yielded an MCID of -6.6 points (SD 11.5) for the TSDS, consistent with prior research. The sensitivity-specificity approach identified an optimal cutoff of a decrease of at least four points, and distribution-based estimates were 4.25 and 7.08 points. The sample size for deterioration was too small to draw meaningful conclusions. Individual symptom domains showed varying patterns of change.

CONCLUSION

Our findings for improvement are consistent with previously established MCID values for the ESAS TSDS, providing supportive evidence for its use as an outcome measure in palliative care research.