178 - Which Domains of the ODI Are Associated with Improved Physical Health...

#178 Which Domains of the ODI Are Associated with Improved Physical Health Status after One-level Fusion for Lumbar Degenerative Spondylolisthesis?

Value and Outcomes in Spine Surgery

Poster Presented by: K. Nicholson

Author(s):

K. Nicholson (1)
S. Stake (1)
B. Woods (2)
G. Schroeder (2)
D.G. Anderson (2)
C. Kepler (2)
M. Kurd (2)
J. Rihn (2)
A. Vaccaro (2)
A. Hilibrand (2)
K. Radcliff (2)

(1) Rothman Institute, Philadelphia, PA, United States
(2) Rothman Institute, Thomas Jefferson University, Philadelphia, PA, United States

Abstract

Introduction: The Oswestry Disability Index (ODI) Questionnaire is a well-established, easily scored ten-item questionnaire about disability associated with generalized back pain: pain intensity, personal care, lifting, walking, sitting, standing, sleeping, sex life, social life, and traveling. The ODI is a sensitive measure for detecting change after treatment for sciatica or generalized back pain. However, ODI improvement varies widely in patient populations surgically treated for lumbar spondylolisthesis, making it less sensitive at determining treatment effectiveness. The purpose of this study was to determine which domains of the ODI improve most after a one-level fusion for degenerative spondylolisthesis and whether improvement in the composite ODI score or specific domains better predicts change in physical function.

Materials and Methods: Analysis of a prospectively-kept registry of patients treated at a major academic medical center. Prior to treatment (baseline), standardized outcome measures including ODI and SF12 PCS were collected. Preoperative outcome measures were compared to those at one year after surgery using paired Student's t-tests. For this study, each of the ten items was treated separately. Multiple linear regressions with backwards variable elimination were performed using change in SF12 PCS as the dependent variable and change in ODI components as the independent variables.

Results: A total of 77 patients had complete baseline and 1 year follow-up data (mean age 60 years). Each of the ten ODI components significantly improved from baseline (p< 0.001). The ODI items with the largest improvements from baseline were: standing (mean -1.68 95% CI [-1.37,-1.98]), social life (-1.66 [-1.35, -1.96]), sex life (-1.59 [-1.20, -1.98]), traveling (-1.46 [-1.16, -1.77]), and pain intensity (-1.42, [-1.16, -1.67]). Overall mean improvement in the composite score was -26.11 [22.19, 30.05]; mean improvement in PCS was 9.16 [7.17, 11.15]. Linear regression for change in ODI components versus change in SF12 PCS revealed a significant, but weak correlation (r2 = 0.2515, p=0.004). The only significant (p=0.001) predictor value was change in lifting (-1.92, [-3.54, -0.30]), which had a mean difference of -1.40 [1.01, 1.78]. Walking (mean change -0.96 [-0.67, -1.24]) and traveling were the only other components with robust coefficients (walking -2.14, [-4.62, 0.35]; traveling -1.52 [-3.41, 0.38]) but were not significant (p=0.090 and p=0.11, respectively). There was a significant (p< 0.001), but weaker linear correlation (r2 = 0.206) between the change in composite ODI and change in PCS. Multiple linear regression incorporating only lifting, walking, and traveling was also significant (p< 0.001) and slightly stronger (r2 = 0.313).

Conclusion: The ODI domains with the largest improvement after a one level fusion for lumbar degenerative spondylolisthesis do not correlate to improvement in overall physical health status. Although the lifting domain only moderately improved, it had the strongest correlation to PCS improvement. The composite change in ODI is weakly correlated to change in PCS; this correlation slightly improves when only the domains for lifting, walking, and traveling are included. This data suggests that the item bank of the ODI is not appropriate for evaluating overall quality of life improvement after surgical treatment for lumbar degenerative spondylolisthesis.