LAUSR

BACKGROUND Patient-level costs of inpatient and outpatient total shoulder arthroplasty (TSA) irrespective of payer status are seldom reported. The purpose of this study was to compare patient-level costs of primary elective TSA between inpatient and outpatient surgery centers. METHODS By use of the Texas Health Care Information Collection database, inpatient and outpatient TSAs performed between 2010 and 2015 were identified according to billing codes. Patient-level costs (total charges and itemized charges) were analyzed according to type of surgery center (inpatient vs outpatient) and inpatient volume (high volume vs low volume). Statistical comparisons were performed using 1-way analysis of variance and 2-sample independent t tests. Mixed-model analysis of variance was used to compare the rate of cost change between inpatient and outpatient TSAs from 2010-2015. P < .05 represented statistical significance. RESULTS A total of 21,331 inpatient TSAs and 1542 outpatient TSAs were performed from 2010-2015 in the state of Texas. Inpatient TSA costs were significantly higher than outpatient TSA costs ($76,109 [standard deviation (SD), $48,981] vs $22,907 [SD, $13,599]; P < .001). After exclusion of inpatient-specific charges, inpatient TSA remained 41.1% more expensive than outpatient TSA ($32,330 [SD, $24,221] vs $22,907 [SD, $13,599]; P < .0001). High-volume inpatient TSA was less expensive than low-volume inpatient TSA; however, high-volume inpatient TSA remained 33.4% more costly than outpatient TSA even after exclusion of inpatient-specific charges ($30,579 [SD, $23,233] vs $22,907 [SD, $13,599]; P < .0001). CONCLUSIONS In the state of Texas, the patient-level costs of primary elective inpatient TSA were significantly higher than those of the equivalent outpatient procedure. This difference persisted after exclusion of low-volume inpatient TSA centers and inpatient-specific ancillary charges.