Minimal Clinically Important Difference and Patient-Acceptable Symptom State in Orthopaedic Spine Surgery: A Review

Minimal clinically important difference (MCID) and patient-acceptable symptom state (PASS) are both metrics at interpreting patient-reported outcome measures (PROMs).

MCID values tend to vary significantly depending on the baseline pain and function in both acute and chronic symptom states while PASS thresholds are more stable.

MCID values are more easily attainable than PASS thresholds.

Although PASS is more relevant to the patient, it should continue to be used in tandem with MCID when interpreting PROM data.