Measuring clinically relevant improvement after lumbar spine surgery: is it time for something new?

Minimum clinically important difference (MCID) for patient-reported outcome measures is commonly used to assess clinical improvement. However, recent literature suggests that an absolute point-change may not be an effective or reliable marker of response to treatment for patients with low or high baseline patient-reported outcome scores. The multitude of established MCIDs also makes it difficult to compare outcomes across studies and different spine surgery procedures.