Minimum Clinically Important Difference for Oswestry Disability Index Three Months following Lumbar Discectomy is Lower when Anchored to Patient Leg Pain Symptoms.

Study design: Retrospective case series.

Objective: The primary objective of this study is to assess the change in patient reported outcomes from baseline to three months following lumbar discectomy for lumbar disc herniation.

Summary of background data: Delayed surgical intervention may result in worse Patient-Reported Outcomes. Patient-reported outcome measures (PROMs) such as the Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) are essential tools for assessing care for patients with low back pain and are widely used to track outcomes following discectomy.

Methods: A total of 207 study participants were included in this retrospective case series study where PRO data was prospectively collected for all individuals who underwent discectomy within a single metropolitan healthcare system between 2018 and 2023. Data on the ODI and VAS were collected at baseline and again 3 months after discectomy.

Results: ODI, VAS leg pain, and VAS back pain all improved significantly from baseline to 3 months post discectomy. There was no correlation between age or BMI and baseline PROs (r < 0.14).

Conclusion: At 3 months post discectomy, there was a significant decrease in the VAS for back and leg pain as well as significant decrease in the ODI. The anchor-based MCID for ODI differs significantly when anchored based on patient leg pain versus patient back pain. Regardless, discectomy is an effective procedure that produces clinically significant improvement in patient reported outcomes at 3 months post procedure with over 55% of patients meeting MCID regardless of the anchoring question.