260. Preoperative medical comorbidities do not affect minimum clinically important difference (MCID) for lumbar fusion in grade one spondylolisthesis

BACKGROUND CONTEXT Medical comorbidities, particularly anxiety or depression, may potentially influence how patients perceive clinical benefit after surgery. The current study defined and compared minimum clinically important difference (MCID) thresholds in patients with and without anxiety/depression and obesity undergoing fusion for grade 1 degenerative spondylolisthesis. PURPOSE To determine if preoperative psychiatric diagnoses, more than obesity, alters the MCID threshold in patients undergoing fusion for spondylolisthesis. STUDY DESIGN/SETTING Retrospective analysis of multicenter, prospective database. PATIENT SAMPLE Patients who underwent lumbar fusion for grade 1 degenerative spondylolisthesis from January 2014 to August 2017 enrolled in the Quality Outcomes Database (QOD). OUTCOME MEASURES Oswestry Disability Index (ODI), EuroQOL5D (EQ-5D), back (BP, 0-10) and leg pain (LP, 0-10) scores METHODS The QOD was queried for patients who underwent lumbar fusion for grade 1 degenerative spondylolisthesis from January 2014 to August 2017. Patient Reported Outcomes (PROs) included ODI, EQ-5D, BPand LP scores. Both anchor-based and distribution-based methods for MCID calculation were used. RESULTS Of 462 eligible cases, 356 (77%) had complete baseline and 12-month PROs. The MCID values for ODI were similar in patients with and without a diagnosis of obesity (20.58 and 20.69, respectively), and with and without anxiety/depression (24.72 and 22.56, respectively). The MCID values for BP, LP, and EQ-5D were also similar among all groups regardless of method used to determine MCID. CONCLUSIONS MCID thresholds for ODI, EQ5D, back pain and leg pain in patients with and without anxiety/depression and obesity undergoing spinal fusion for grade 1 degenerative spondylolisthesis are similar. Preoperative clinical and shared decision-making may be improved by understanding that preop medical comorbidities do not affect how patients determine an important clinical change postoperatively. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.