Risk Factors for 30-day and 90-day Readmission After Lumbar Decompression

Study Design. Retrospective cohort study. Objective. To assess readmission rates and risk factors for 30-day and 90-day readmission after elective lumbar decompression at a single institution. Summary of Background Data. Hospital readmission is an undesirable aspect of interventional treatment. Studies evaluating readmissions after elective lumbar decompression typically analyze national databases, and therefore have several drawbacks inherent to their macroscopic nature that limit their clinical utility. Methods. Patients undergoing primary one- to four-level lumbar decompression surgery were retrospectively identified. Demographic, surgical, and readmission data within "30-days" (0-30 days) and "90-days" (31-90 days) postoperatively were extracted from electronic medical records. Patients were categorized into four groups: (1) no readmission, (2) readmission during the 30-day or 90-day postoperative period, (3) complication related to surgery, and (4) Emergency Department (ED)/Observational (OBs)/Urgent (UC) care. Results. A total of 2635 patients were included. Seventy-six (2.9%) were readmitted at some point within the 30- (2.3%) or 90-day (0.3%) postoperative periods. Patients in the pooled readmitted group were older (63.1 yr, P < 0.001), had a higher American Society of Anesthesiologists (ASA) grade (31.2% with ASA of 3, P = 0.03), and more often had liver disease (8.1%, P = 0.004) or rheumatoid arthritis (12.0%, P = 0.02) than other cohorts. A greater proportion of 90-day readmissions and complications had surgical-related diagnoses or a diagnosis of recurrent disc herniation than 30-day readmissions and complications (66.7% vs. 44.5%, P = 0.04 and 33.3% vs. 5.5%, P < 0.001, respectively). Age (Odds ratio [OR]: 1.02, P = 0.01), current smoking status (OR: 2.38, P < 0.001), longer length of stay (OR: 1.14, P < 0.001), and a history of renal failure (OR: 2.59, P = 0.03) were independently associated with readmission or complication. Conclusion. Increased age, current smoking status, hospital length of stay, and a history of renal failure were found to be significant independent predictors of inpatient readmission or complication after lumbar decompression.