Black patients more likely to be readmitted after hip, knee replacement surgery

A new study presented today at the 2015 Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS) found that black and Hispanic patients were 62 and 50 percent, respectively, more likely to be readmitted to the hospital within 30 days after total joint replacement (TJR) surgery compared to white patients. In addition, Medicaid patients were 40 percent more likely to be readmitted to the hospital than patients with private insurance.

Disparities in the provision of health care services have long been documented, including that black patients utilize hip and total knee replacement at rates nearly 40 percent less than white patients, despite having comparable or higher rates of osteoarthritis—a leading cause of joint deterioration.

In this study, researchers analyzed five years of data—demographic (including race/ethnicity), clinical and billing—on nearly 53,000 patients admitted to Connecticut hospitals for TJR from 2008 to 2012. The average patient age was 67, and the vast majority of patients were white (87 percent), covered by Medicare (56.7 percent) and female (61 percent).

The overall 30-day readmission rate for patients was 5.2 percent. The most common reasons for readmission were postoperative infection (8 percent), infection and inflammatory reaction due to internal joint prosthesis (6 percent), hematoma complications during a procedure (3 percent) and dislocation of a prosthetic joint (3 percent). Among the other study findings:

• Readmission rates were 83.5 per thousand for black patients, 78.9 for Hispanic patients and 53.3 for white patients.
• Longer length of hospital stay was significantly associated with increased odds of readmission.
• When controlling for comorbidities and type of insurance coverage, the readmission rate for Hispanic patients dropped 44 percent, and for black patients, 38 percent. Black patients remained significantly more likely than white patients to be readmitted following surgery, after controlling for comorbidities.
• Patients covered by Medicare were 30 percent more likely to be readmitted within 30 days following discharged compared to patients covered by private insurance, and Medicaid patients were 40 percent more likely.

Recent research using national data on Medicare suggests that community-based factors, such as availability of general practitioners in the area, may be as or more important than hospital factors in determining readmission rates, and that patients may have few options other than hospital care for both urgent and non-urgent conditions related to their surgery or other conditions.

"Using an all-payer database, our study shows that black patients who undergo total knee replacement may have poorer outcomes," said lead study author and orthopaedic surgeon Courtland Lewis, MD. "After controlling for two key variables implicated in race and ethnic disparities in hospital readmission—preoperative comorbidities and type of insurance coverage—black patients still have a 35 percent higher likelihood of all-cause, 30-day readmission compared to white patients.

"Our ongoing research in this area is focused on other factors, such as the patient's connection to primary care and patient-provider communication, that may explain this troubling finding," said Dr. Lewis.