Objective: The Neuropathic Pain Symptom Inventory (NPSI) is commonly used assessment in Neuropathic Pain (NP) trials, yet a Minimal Clinically Important Difference (MCID) has not been established. A MCID would enhance the interpretability of NPSI scores, guiding clinicians and researchers in assessing clinically important improvements in NP symptoms. The aim of this study was to calculate an MCID from the available scientific research that used the NPSI.  Methods: We conducted a systematic review and meta-analysis of NP trials reporting the NPSI. Three distributional approaches were applied to estimate the MCID: pooled standard deviation (SD) of change scores, pooled baseline SD, and a random-effects meta-analytic approach. Only treatments arms within RTCs were examined. Treatment arms were grouped by NP etiology, enabling etiology-specific MCID estimates. Bias for each included study was assessed using the Cochrane tool for quality assessment of randomized controlled trials. Results: 323 trials were examined, 12 were selected for inclusion for a total of 17 treatment arms. The calculated MCID estimates for the NPSI total score were 7.95 using pooled SD of change scores, 7.73 using pooled baseline SD, and 6.85 using the random-effects method. Etiology-specific MCIDs varied, with Post-Infectious conditions and Diabetic Peripheral Neuropathy showing higher values than other NP types.  Conclusion: This study provides preliminary MCID estimates for the NPSI. Limitations include limited data for certain NP subtypes, highlighting the need for additional anchor-based and etiology-specific MCID research to refine these estimates. These findings can aid in future NP trial design and the interpretation of results.

The authors have declared no competing interest.

The author(s) received no specific funding for this work.

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This was a systematic review. no IRB was necessary.

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