Medicaid is associated with increased readmission and resource utilization after primary total knee arthroplasty: a propensity score–matched analysis

Abstract

BackgroundMedicaid payer status has been shown to affect resource utilization across multiple medical specialties. There is no large database assessment of Medicaid and resource utilization in primary total knee arthroplasty (TKA), which this study sets out to achieve.MethodsThe Nationwide Readmissions Database was used to identify patients who underwent TKA in 2013 and corresponding “Medicaid” or “non-Medicaid” payer statuses. Demographics, 15 individual comorbidities, readmission rates, length of stay, and direct cost were evaluated. A propensity score–based matching model was then used to control for baseline confounding variables between payer groups. A chi-square test for paired proportions was used to compare readmission rates between the 2 groups. Length of stay and direct cost comparisons were evaluated using the Wilcoxon signed-rank test.ResultsA total of 8372 Medicaid and 268,261 non-Medicaid TKA patients were identified from the 2013 Nationwide Readmissions Database. A propensity score was estimated for each patient based on the baseline demographics, and 8372 non-Medicaid patients were propensity score matched to the 8372 Medicaid patients. Medicaid payer status yielded a statistically significant increase in overall readmission rates of 18.4% vs 14.0% (P < .0001, relative risk = 1.31, 95% confidence interval [1.23-1.41]) with non-Medicaid status and 90-day readmission rates of 10.0% vs 7.4%, respectively (P < .001, relative risk = 1.35, 95% confidence interval [1.22-1.48]). The mean length of stay was longer in the Medicaid group compared with the non-Medicaid group at 4.0 days vs 3.3 days (P < .0001) as well as the mean total cost of $64,487 vs $61,021 (P < .0001).ConclusionsThis study demonstrates that Medicaid payer status is independently associated with increased resource utilization, including readmission rates, length of stay, and total cost after TKA.

Trends in Postacute Care Use and Outcomes After Hip and Knee Replacements in Dual-Eligible Medicare and Medicaid Beneficiaries, 2013-2016

“…Previous studies showed that Medicaid patients had higher rates of inpatient resource use, higher costs, and higher rates of readmission after hip or knee replacement than non-Medicaid patients. [12][13][14][15][16][17] However, research is lacking on PAC disparities after joint replacement surgery. This study contributes to the literature by demonstrating more intensive institutional PAC use but lower PAC quality and outcomes for dual-eligible patients relative to Medicare-only patients.…”

The Impact of Preoperative Opioid Use Disorder on Complications and Costs following Primary Total Hip and Knee Arthroplasty

“…It additionally allows for controlling of socioeconomic factors by reporting insurance status as well as zip code income quartile. Both factors that have been associated with outcomes [37][38][39], and the ability to control for these represents an important strength compared to other database studies. Also, readmissions can be tracked even if the readmission occurs at a different institution, therefore providing a higher capture rate for outcomes.…”

Medicare coverage is an independent predictor of prolonged hospitalization after primary total joint arthroplasty

“…To our knowledge, this is the first study to explore the effect of the 3 major insurance types (Medicaid, Medicare, and commercial) on hospital LOS and 90-day global events in fast-track primary total hip and knee arthroplasty. Previous studies have stratified patients into Medicaid or non-Medicaid payer status or had relatively high mean LOS [8], [9], [10]. Browne et al [8] retrospectively reviewed 191,111 patients who underwent primary TJA between 2002 and 2011 using the Nationwide Inpatient Sample.…”

“…Only 2 studies dissected the effect of payer type on LOS into the 3 major insurance groups (Medicaid, Medicare, and commercial), but only in THA [5], [11]. Collectively, these studies found higher rates of in-hospital morbidity, prolonged LOS, and resource utilization among Medicaid and Medicare patients [5], [8], [9], [10], [11]. We are not aware of similar reports comparing the 3 major insurance groups in TKA.…”

“…Despite concerns in the arthroplasty community regarding CMS’ position [7], there are currently limited data on the association between insurance type and LOS. Most studies to date have stratified patients into Medicaid vs non-Medicaid groups [8], [9], [10]. Only 2 studies dissected the effect of payer type on LOS into the 3 major insurance groups (Medicaid, Medicare, and commercial), but only in THA [5], [11].…”