Christopher S. Hollenbeak, PhD, Professor and Department Head of Health Policy and Administration at Pennsylvania State University, and colleagues conducted a statewide analysis using data from the Pennsylvania Health Care Cost Containment Council (PHC4) and authored a study, 30-Day Readmission Following Inpatient Total Shoulder Arthroplasty (TSA) in Pennsylvania1. This work was motivated by the increasing emphasis on readmission reduction under value-based purchasing programs, including the Medicare Hospital Readmission Reduction Program (HRRP), and the rising utilization of TSA in an aging population. They were interested in providing empirical evidence to help health care providers identify high-risk patients and to inform them of potential interventions in order to prevent readmissions following a TSA. The study examined trends in readmission rates and patient comorbidity burden among inpatient hospitalizations in Pennsylvania from 2010 through 2018. Dr. Hollenbeak shared observations from the analysis, explaining, “We observed that readmission rates fell slightly through 2014 and rose modestly through 2018, though the trend was not statistically significant. Another important time-trend we saw was a steady increase in the comorbidity index over the same period, which we believe represents a selection effect as more TSA is performed in the ambulatory setting.”
Multivariable analyses identified several factors significantly associated with 30-day readmission. Medicaid coverage was associated with nearly twice the odds of readmission, while patients with three or more comorbidities experienced up to a threefold increase in risk. Discharge disposition was also significant: patients discharged to skilled nursing facilities or with home health services had elevated readmission risk. Additional risk factors included reverse TSA (relative to anatomic TSA) and urgent or emergent admission status. These findings highlight potential targets for intervention, such as enhanced transitional care for patients discharged to post-acute care settings and more intensive post-discharge monitoring for high-risk populations.
Additionally, Dr. Hollenbeak noted, “The overall 30-day readmission rate across all years was 3.3%, which is consistent with other national estimates.” Although Medicare beneficiaries exhibited higher readmission rates in unadjusted analyses, payer status was not independently significant after controlling for comorbidities and other factors. In contrast, Medicaid coverage remained a significant predictor after adjustment. The leading causes of readmission were infection (12.3%), cardiovascular conditions (11.2%), and pulmonary issues (10.8%). The relatively high proportion of cardiovascular readmissions following TSA warrants further investigation.
A key strength of the study was the use of PHC4 data. Dr. Hollenbeak expressed, “The PHC4 data allowed us to build a large, statewide cohort, track readmissions to any Pennsylvania hospital, and control for key covariates like demographics, comorbidities, and discharge destination. For researchers studying hospital utilization, readmissions, costs, or disparities in Pennsylvania, PHC4 is an invaluable resource. It is one of the few state-level datasets that captures all-payer, all-hospital admissions and allows readmission tracking across facilities. We particularly recommend it for research involving hospital quality and outcomes research in surgery.”
Dr. Hollenbeak acknowledged the contributions of his co-authors, Brian Johnson, an honors student whose undergraduate thesis work initiated the study, and April D. Armstrong, MD FACS, an orthopedic surgeon and C. McCollister Evarts Professor and Chair of the Department of Orthopaedics at Penn State College of Medicine. The study reflects a multidisciplinary collaboration integrating health policy, clinical expertise, and quantitative analysis. Dr. Hollenbeak said, “This paper was a true collaboration between the three of us and would not have been possible without their valuable insights and contributions.”
1 Johnson J, Armstrong A, Hollenbeak C. 30-Day Readmission Following Inpatient Total Shoulder Arthroplasty in Pennsylvania. JBJS Open Access. 11(1):e25.00206, January-March 2026. doi: 10.2106/JBJS.OA.25.00206.
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