BACKGROUND CONTEXT The single-item outcome measure of Global Ratings Change (GRC) has been shown to be a feasible overall patient-reported outcome measure (PROM) among patients undergoing spine surgery. While predictors of best overall outcomes after minimally invasive (MIS) spine surgery have been identified, predictors of non-improvement after surgery remain to be investigated. PURPOSE To identify the predictors of non-improvement based on GRC after MIS lumbar spine surgery. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE Patients who underwent MIS transforaminal interbody fusion (TLIF), laminectomy or microdiscectomy at a single institution between 2017-2021. OUTCOME MEASURES Global ratings change, demographics, comorbidities, surgical details, PROMs including Oswestry Disability Index (ODI), VAS (Visual Analog Scale) back, VAS leg, SF-12 MCS (Short Form 12 Mental Component Score) and SF-12 PCS (Physical Component Score). METHODS Patients with followup of <6 months or missing preoperative PROMs data were excluded. Patients were grouped into 3 cohorts based on GRC at long-term followup (LTFU) - better, same or worse after surgery. LTFU was defined as the latest followup data available between 6 months and 2 years. For regression analysis, the GRC variable was binarized into improvement vs non-improvement (same or worse after surgery). Multivariate binary logistic regression models were utilized to identify the risk factors for non-improvement. RESULTS The total cohort included 448 patients; 191 patients underwent TLIF, 129 patients underwent laminectomy and 128 patients underwent microdiscectomy. Sixty-six patients (14.7%) reported no improvement at LTFU postoperatively; among these, 35 patients (7.8%) reported worsening after surgery, while 31 patients (6.9%) reported no change. Patients who worsened after surgery were older on average compared to patients who improved after surgery (63.7±15.5 vs. 56.8±15.1, p=0.014). Obesity was more common among patients with no change at LTFU compared to those who improved (41.9% vs 19.1%, p=0.007). There were no differences in GRC among types of surgery or number of surgical levels. There were no differences in any preoperative PROMs scores based on GRC cohorts. Multivariate regression analysis identified age 65 (OR 2.333 [CI95 1.230-4.42], p=0.010), obesity (BMI 30 kg/m2) (2.416 [1.307-4.469], p=0.005), and smoking (3.669 [1.141-11.799], p=0.029) as independent risk factors for non-improvement after MIS lumbar spine surgery. Sex, education level, employment, Charlson Comorbidity Index, anxiety and depression did not independently predict non-improvement after surgery. In addition, type of surgery, number of surgical levels and preoperative PROM scores also did not predict non-improvement. CONCLUSIONS The current study demonstrates that age 65, obesity and smoking are independent predictors of non-improvement after MIS lumbar spine surgery. Sex, education level, employment, Charlson Comorbidity Index, anxiety, depression, type of surgery, number of surgical levels and preoperative PROM scores are not risk factors for non-improvement after surgery. This study provides valuable evidence which can benefit the surgical decision-making process and allow for more thorough patient education. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. The single-item outcome measure of Global Ratings Change (GRC) has been shown to be a feasible overall patient-reported outcome measure (PROM) among patients undergoing spine surgery. While predictors of best overall outcomes after minimally invasive (MIS) spine surgery have been identified, predictors of non-improvement after surgery remain to be investigated. To identify the predictors of non-improvement based on GRC after MIS lumbar spine surgery. Retrospective cohort study. Patients who underwent MIS transforaminal interbody fusion (TLIF), laminectomy or microdiscectomy at a single institution between 2017-2021. Global ratings change, demographics, comorbidities, surgical details, PROMs including Oswestry Disability Index (ODI), VAS (Visual Analog Scale) back, VAS leg, SF-12 MCS (Short Form 12 Mental Component Score) and SF-12 PCS (Physical Component Score). Patients with followup of <6 months or missing preoperative PROMs data were excluded. Patients were grouped into 3 cohorts based on GRC at long-term followup (LTFU) - better, same or worse after surgery. LTFU was defined as the latest followup data available between 6 months and 2 years. For regression analysis, the GRC variable was binarized into improvement vs non-improvement (same or worse after surgery). Multivariate binary logistic regression models were utilized to identify the risk factors for non-improvement. The total cohort included 448 patients; 191 patients underwent TLIF, 129 patients underwent laminectomy and 128 patients underwent microdiscectomy. Sixty-six patients (14.7%) reported no improvement at LTFU postoperatively; among these, 35 patients (7.8%) reported worsening after surgery, while 31 patients (6.9%) reported no change. Patients who worsened after surgery were older on average compared to patients who improved after surgery (63.7±15.5 vs. 56.8±15.1, p=0.014). Obesity was more common among patients with no change at LTFU compared to those who improved (41.9% vs 19.1%, p=0.007). There were no differences in GRC among types of surgery or number of surgical levels. There were no differences in any preoperative PROMs scores based on GRC cohorts. Multivariate regression analysis identified age 65 (OR 2.333 [CI95 1.230-4.42], p=0.010), obesity (BMI 30 kg/m2) (2.416 [1.307-4.469], p=0.005), and smoking (3.669 [1.141-11.799], p=0.029) as independent risk factors for non-improvement after MIS lumbar spine surgery. Sex, education level, employment, Charlson Comorbidity Index, anxiety and depression did not independently predict non-improvement after surgery. In addition, type of surgery, number of surgical levels and preoperative PROM scores also did not predict non-improvement. The current study demonstrates that age 65, obesity and smoking are independent predictors of non-improvement after MIS lumbar spine surgery. Sex, education level, employment, Charlson Comorbidity Index, anxiety, depression, type of surgery, number of surgical levels and preoperative PROM scores are not risk factors for non-improvement after surgery. This study provides valuable evidence which can benefit the surgical decision-making process and allow for more thorough patient education.