P131. The association of comorbidity burden on lumbar decompression postoperative outcomes

Abstract

BACKGROUND CONTEXT Central stenosis of the spinal canal can be surgically managed through decompression techniques. There is a lack of research on the influence of comorbidity burden on postoperative patient reported outcome (PRO) improvement and on the achievement of minimum clinically important difference (MCID) following lumbar decompression (LD). PURPOSE This study aims to detail the association between comorbidity burden and achievement of MCID following LD. STUDY DESIGN/SETTING Retrospective. PATIENT SAMPLE A total of 314 patients undergoing primary or revision, 1 or 2 level MIS TLIF procedures. OUTCOME MEASURES VAS back, VAS leg, ODI, SF-12 Physical Composite Score (PCS), and PROMIS PF scores, MCID. METHODS A prospectively maintained surgical registry was retrospectively reviewed for eligible spine surgeries between May 2015 and July 2019. Inclusion criteria were primary, single or multilevel lumbar decompressions. Patients were excluded if they did not complete a preoperative Patient-Reported Outcomes Measurement Information System physical function (PROMIS PF) survey. Patients were stratified based on Charlson Comorbidity Index (CCI) score: 0 points (no comorbidities), 1–2 points (low CCI), ≥3 points (high CCI). A chi-squared test analyzed the association of CCI subgroups in the following variables: gender, smoking status, comorbid diagnoses, and body mass index (BMI). A t-test was used to evaluate subgroups for mean differences in continuous variables, such as age, operative time (from skin incision to closure), estimated blood loss, length of stay, and discharge day (Table 2). A chi-squared test evaluated the distribution of decompression levels. Postoperative improvement was assessed using linear regression to detect a difference between CCI groups for VAS back, VAS leg, ODI, SF-12 Physical Composite Score (PCS), and PROMIS PF scores pre- and postoperatively (eg, 6 weeks, 12 weeks, 6 months and 1 year). Achievement rate of MCID was compared between CCI groups using chi-squared analysis (Table 4). MCID values utilized were VAS back = 1.2, VAS leg = 1.6, ODI = 12.8, SF-12 PCS = 4.0, and PROMIS PF = 8.0. RESULTS A total of 314 LD patients were included; 123 patients had no comorbidities, 100 had low CCI, and 91 had high CCI. Patients with a high CCI were older, more likely to be smokers, and to have the following comorbid diseases: myocardial infarction, diabetes, arthritis, hypertension, PVD, neurological disease and cancer (all p CONCLUSIONS Patients with increased comorbidity burdens undergoing LD had significantly longer procedure times and hospital stays, but their postoperative evaluations demonstrated no difference in achieving MCID for pain (VAS back and VAS leg) or disability (ODI) metrics up to 1-year. Patients in the high CCI group did, however, have a lower rate of achieving MCID for their physical function surveys. Our results suggest that comorbidity burden influences improvement in physical function following LD. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.