The drivers behind inequality are multifaceted, says Nicolas S. Piuzzi, M.D., associate professor of orthopaedic surgery and co-director of the Musculoskeletal Research Center at Cleveland Clinic, and demand more than a quick fix.
His new study comes as we are hearing more about the effects of social determinants on orthopedic outcomes, with at least one study finding that patients with lower education had higher rates of readmission and major complications.
Along with colleagues, Dr. Piuzzi has conducted research asking whether race was independently associated with adverse outcomes (length of stay > 3 days), nonhome discharge, 90-day readmission, and emergency department (ED) visits and whether socioeconomic disadvantage substantially mediated any association between race and the above outcomes.
Their study, “Racial Disparities in Outcomes After THA and TKA Are Substantially Mediated by Socioeconomic Disadvantage Both in Black and White Patients,” appears in the September 14, 2022, edition of Clinical Orthopaedics and Related Research.
Describing the parameter they used as a proxy for socioeconomic disadvantage, the Area Deprivation Index, Dr. Piuzzi explained to OTW, “The Area Deprivation Index, created by a research group at Wisconsin-Madison, provides a metric of ranking neighborhoods by socioeconomic disadvantage, taking into account education level, income, employment, and housing quality.
The National Area Deprivation Index relies on the United States Census Block Groups and provides percentile scores ranging from 1-100, which are normalized, with higher scores indicating an increased disadvantage.”
The researchers looked at 2,638 patients who underwent elective primary total hip arthroplasty (THA) and 4,915 patients who had elective primary total knee arthroplasty (TKA) for osteoarthritis at one of seven hospitals (one academic center). Included were 742 Black patients (12%) and 5,206 White patients (88%).
For both THA and TKA, Black patients had higher Area Deprivation Index scores, slightly higher body mass index (BMI) scores, and were more likely to be current smokers at baseline. Also, in the TKA cohort there was a higher proportion of Black women than White women.
Of the THA patients, after adjusting for age, gender, BMI, smoking, Charlson comorbidity index, and insurance, White patients had lower odds of experiencing a length-of-stay of three days or more and nonhome discharge. The authors found that the Area Deprivation Index partially explained 37% of the association between race and length-of-stay of three days or more and 40% of the association between race and nonhome discharge. However, the team found a smaller direct association between race and both outcomes.
They found no association between race and 90-day readmission or emergency department admission in those undergoing THA. Among the TKA patients, after adjusting for age, gender, BMI, smoking, Charlson comorbidity index, and insurance, White patients had lower odds of experiencing a length-of-stay of 3 days or more, nonhome discharge, 90-day readmission, and 90-day emergency department admission.
The researchers determined that the Area Deprivation Index mediated 19% of the association between race and length-of-stay of 3 days or more and 38% of the association between race and nonhome discharge, but there was also a direct association between race and these outcomes: length-of-stay 3 days or more and nonhome discharge. The Area Deprivation Index did not mediate the associations observed between race and 90-day readmission and ED admission in the TKA group.
Dr. Piuzzi commented to OTW, “Our findings suggest that socioeconomic disadvantage may be implicated in a substantial proportion of the previously assumed race-driven disparity in healthcare utilization parameters after primary total joint arthroplasty.”
“Orthopedic surgeons should attempt to identify potentially modifiable socioeconomic disadvantage indicators. This serves as a call to action for the orthopedic community to consider specific interventions to support patients from vulnerable areas or whose incomes are lower, such as supporting applications for nonemergent medical transportation or referring patients to local care coordination agencies.”
