Insurance Payer Type and Patient Income Are Associated with Outcomes after Total Shoulder Arthroplasty

To assess the independent association of insurance and patient income with total shoulder arthroplasty (TSA) outcomes.

We used the 1998-2014 US National Inpatient Sample. We used multivariable-adjusted logistic regression to examine whether insurance type and the patient's median household income (based on postal code) were independently associated with healthcare use (discharge destination, hospital stay duration, total hospital charges) and in-hospital complications post-TSA based on the diagnostic codes (fracture, infection, transfusion, or revision surgery). We calculated the OR and 95% CI.

Among the 349,046 projected TSA hospitalizations, the mean age was 68.6 years, 54% were female, and 73% white. Compared to private insurance, Medicaid and Medicare (government insurance) users were associated with significantly higher adjusted OR (95% CI) of (1) discharge to a rehabilitation facility, 2.16 (1.72-2.70) and 2.27 (2.04-2.52); (2) hospital stay > 2 days, 1.65 (1.45-1.87) and 1.60 (1.52-1.69); and (3) transfusion, 1.35 (1.05-1.75) and 1.39 (1.24-1.56), respectively. Medicaid was associated with a higher risk of fracture [1.74 (1.07-2.84)] and Medicare user with a higher risk of infection [2.63 (1.24-5.57)]; neither were associated with revision. Compared to the highest income quartile, the lowest income quartile was significantly associated with (OR, 95% CI): (1) discharge to a rehabilitation facility (0.89, 0.83-0.96); (2) hospital stay > 2 days (0.84, 0.80-0.89); (3) hospital charges above the median (1.19, 1.14-1.25); (4) transfusion (0.73, 0.66-0.81); and (5) revision (0.49, 0.30-0.80), but not infection or fracture.

This information can help to risk-stratify patients post-TSA. Future assessments of modifiable mediators of these complications are needed.