1528. Correlation between ODI and PROMIS in Minimally Invasive Lumbar Microdiscectomy

Authors: Avani Vaishnav; Steven McAnany, MD; Brittany Haws, MD; Benjamin Khechen, BA; Kern Singh, MD; Catherine Gang, MPH; Sheeraz Qureshi, MD, MBA (New York, NY)

Introduction:
As the focus in spine surgery shifts from radiographic to patient-centric outcomes, patient-reported outcomes measures (PROMs) are becoming increasingly important. Thus, it is vital interpret and evaluate these tools.

Objectives:
To evaluate the correlation between ODI and PROMIS Physical Function(PROMIS-PF) in patients undergoing minimally invasive lumbar microdiscectomy. 

Methods:
PROMs collected pre-operatively and 6 weeks, 3 months, 6 months and 1 year post-operatively were analyzed using Pearson product-moment correlation. Paired samples t-test was used to assess change in PROMs and an MCID of 12.8 for ODI was used to evaluate clinically significant improvement.

Results: 
A total of 182 patients, with 171 one-level and 11 two-level procedures were included. The most common operative levels were L4-L5 or L5-S1, with about 90% of discectomies being performed at these levels, with an equal number at L4-L5 and L5-S1.

The mean change in ODI and PROMIS from the pre-operative visit to each follow-up was statistically significant. In addition, 62.7% of patients had an improvement >MCID on the ODI by 6 weeks, 67% by 12 weeks, 67.2% by 6 months and 69.6% by 1 year.

The results of the correlation showed a statistically significant negative correlation at all time-points, which was moderate preoperatively (r=-0.58,n=182,p<0.0001), strong at 6-weeks (r=-0.72,n=111,p<0.0001), and very strong at 3-months (r=-0.82,n=69,p<0.0001), 6-months (r=-0.80,n=54,p<0.0001), and 1-year (r=-0.85,n=41,p<0.0001).

Conclusion: 
While ODI has been used to evaluate outcomes in lumbar spine patients for several years, PROMIS is a relatively new outcome measure that is increasingly being implemented. The results of our study show a very strong negative correlation between ODI and PROMIS in the post-operative period, especially at 3 months or greater follow-up. Thus, PROMIS-PF is a good surrogate for ODI in assessing post-operative outcomes. Larger studies are warranted to evaluate the true utility and value of this outcome measure.