Need for Two-Year Patient-Reported Outcomes Score for Lumbar Spine Surgery Is Procedure-Specific: Analysis From a Prospective Longitudinal Spine Registry.
METHODS
Retrospective analysis of prospectively collected data.


OBJECTIVE
The aim of this study was to determine whether 1-year patient-reported outcomes (PROs) can accurately assess effective care for patients undergoing surgery for degenerative lumbar spine disease.


BACKGROUND
Prospective longitudinal PROs registries provide a means to accurately assess outcomes and determine the relative effectiveness of various spine treatments. Obtaining long-term PROs can be costly and challenging.


METHODS
Patients enrolled into a prospective registry who underwent lumbar spine surgery for degenerative disease were included. Baseline, 1-year, and 2-year Oswestry Disability Index (ODI) scores were captured. Previously published minimum clinically important difference (MCID) for ODI (14.9) was used. Multivariable linear regression model was created to derive model-estimated 2-year ODI scores. Absolute differences between 1-year and 2-year ODI were compared to absolute differences between 2-year and model-estimated 2-year ODI. Concordance rates in achieving MCID at 1-year and 2-year and predictive values were calculated.


RESULTS
A total of 868 patients were analyzed. One-year ODI scores differed from 2-year scores by an absolute difference of 9.7 ± 8.9 points and predictive model-estimated 2-year scores differed from actual 2-year scores by 8.8 ± 7.3 points. The model-estimated 2-year ODI was significantly different than actual 1-year ODI in assessing actual 2-year ODI for all procedures (P = 0.001) except for primary (P = 0.932) and revision microdiscectomy (P = 0.978) and primary laminectomy (P = 0.267). The discordance rates of achieving or not achieving MCID for ODI ranged from 8% to 27%. Concordance rate was about 90% for primary and revision microdiscectomy. The positive and negative predictive value of 1-year ODI to predict 2-year ODI was 83% and 67% for all procedures and 92% and 67% for primary and 100% and 86% for revision microdiscectomy respectively.


CONCLUSIONS
One-year disability outcomes can potentially estimate 2-year outcomes for patient populations, but cannot reliably predict 2-year outcomes for individual patients, except for patients undergoing primary and revision microdiscectomy.


METHODS
4.
Department of Orthopaedic Surgery and Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN.
Elliott J
EJ
Kim
Department of Orthopaedic Surgery and Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN.
Silky
S
Chotai
Department of Orthopaedic Surgery, Vanderbilt University Medical Center, Nashville, TN.|Department of Physical Medicine and Rehabilitation, Vanderbilt University Medical Center, Nashville, TN.
Kristin R
KR
Archer
Department of Neurosurgery, Mayo Clinic, Rochester, MN.
Mohamad
M
Bydon
Department of Neurological Surgery, Carolina Neurosurgery and Spine Associates, Charlotte, NC.
Anthony L
AL
Asher
Department of Orthopaedic Surgery and Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN.
Clinton J
CJ
Devin
D004185:Disability Evaluation; D019538:Health Care Surveys / Q000592:standards*; D006801:Humans; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000601:surgery*; D019637:Orthopedic Procedures / Q000009:adverse effects / Q000379:methods / Q000706:statistics & numerical data; D000071066:Patient Reported Outcome Measures; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome