Trends and Outcomes in Patients with Dementia Undergoing Spine Fusions: A Matched Nationwide Inpatient Sample Analysis

Background: The aim of our study was to define the trends and outcomes in patients with a preexisting diagnosis of dementia who underwent spine fusions using a large national database. Methods: The Nationwide Inpatient Sample database was queried using the International Classification of Diseases, Ninth Revision and Tenth Revision, from 1998 to 2018. We included patients who underwent spine fusions with or without the diagnosis of dementia. Outcomes were trends, complications, length of stay (LOS), discharge disposition, and mortality. Results: A cohort of 4495 patients (N = 1,390,657; 0.32%) with dementia who underwent spine fusions was identified. There was an increasing trend of spine fusions in patients with the diagnosis of dementia. Most patients with dementia were white (77% vs. 69%), with ≥3 comorbidities (70% vs. 23%), had Medicare insurance (83% vs. 34%) compared with patients without dementia (P < 0.0001). Overall, 38% of patients had complications after spine fusions compared with 21% of patients without dementia during the study period. Median LOS was significantly longer in patients with dementia compared with patients without dementia (6 vs. 4 days). Patients with dementia were less likely to be discharged home (19% vs. 40%) and incurred higher in-hospitalization charges ($139,101 vs. $101,629) compared with patients without dementia. No differences in terms of in-hospital mortality were noted across the cohorts (1.4% vs. 1.6%). Conclusions: Patients with dementia had 1.5 times longer LOS and 1.4 times higher index hospitalization charges and were 2.5 times more likely to have complications and 71% less likely to be discharged home, with no difference in mortality compared with patients without dementia after spine fusions.