What are the predictors of nonroutine discharge after surgery for grade 2 lumbar spondylolisthesis? A Spine CORe™ analysis of QOD data

OBJECTIVE: Discharge to an inpatient rehabilitation facility or other acute care facility is a significant driver of healthcare costs. The authors sought to identify predictors of nonroutine discharge after surgery for grade 2 lumbar spondylolisthesis. METHODS: The Quality Outcomes Database from the 14 highest enrolling sites (Spine CORe™ study group) was queried for adult patients who underwent surgery for grade 2 lumbar spondylolisthesis. Nonroutine discharge was defined as discharge to a postacute or nonacute care setting or transfer to another acute care facility. Univariate analysis and multivariate logistic regression were utilized to identify predictors of nonroutine discharge. The follow-up rate at 5 years was 81%. RESULTS: Of the 328 patients identified, 47 (14.3%) had nonroutine discharge. On univariate analysis, patients with nonroutine discharge were more likely to be older (67.4 ± 11.3 years vs 59.4 ± 12.2 years, p < 0.0001), be female (85.1% vs 65.5%, p = 0.007), have diabetes (36.2% vs 12.1%, p < 0.0001), have osteoporosis (21.3% vs 8.2%, p = 0.02), have a higher mean baseline numeric rating scale (NRS) leg pain score (7.5 ± 2.2 vs 6.6 ± 2.8, p = 0.04), and have a higher mean baseline Oswestry Disability Index (ODI) score (55.4 ± 15.7 vs 46.5 ± 16.5, p = 0.0006) compared to patients with a routine discharge. Patients who had completed a 4-year college degree, were employed and working, and were independently ambulatory were more likely to have a routine discharge (p < 0.0001). Multivariate analysis showed that older age (OR 1.06, 95% CI 1.01-1.11, p = 0.01), female sex (OR 2.64, 95% CI 1.01-6.87, p = 0.04), need for an assistive device to ambulate preoperatively (OR 3.01, 95% CI 1.02-7.36, p = 0.02), and diabetes (OR 2.80, 95% CI 1.20-6.56, p = 0.02) were independently associated with nonroutine discharge. Patients with a nonroutine discharge had significantly greater length of stay compared to patients with a routine discharge (4.7 ± 2.2 vs 3.2 ± 2.1 days, p < 0.0001). CONCLUSIONS: In this large, prospective, multicenter study, patients with nonroutine discharge after surgery for grade 2 lumbar spondylolisthesis were more likely to be older, female, have diabetes, and require an assistive device to ambulate preoperatively.