About

Douglas E. Schaubel, PhD, is a Professor of Biostatistics in the Department of Biostatistics and Epidemiology at the University of Pennsylvania's Perelman School of Medicine. He is affiliated with the Graduate Group in Epidemiology and Biostatistics. His educational background includes a BMath in Actuarial Science and Statistics from the University of Waterloo, an MSc in Biostatistics from McGill University, and a PhD in Biostatistics from the University of North Carolina at Chapel Hill. Dr. Schaubel's research focuses on biostatistics and epidemiology, contributing to the understanding of transplantation outcomes, liver and kidney diseases, and infectious disease impacts on transplant success. His work involves analyzing clinical data to improve patient care and transplant procedures, as evidenced by his numerous publications in reputable medical journals.

Research topics

• Internal medicine
• Medicine
• Demography

Selected publications

• A Novel Measurement of Altered Achilles Subtendon Load Sharing 6–12 Months Following Rupture

  Journal of Orthopaedic Research® · 2026-03-26

  articleOpen access

  Achilles tendon ruptures cause muscle-tendon structural and functional deficits that persist years after the initial injury. A healthy Achilles tendon contains three semi-independent subtendons that slide relative to each other during muscle contractions in healthy adults. However, such sliding decreases postinjury as load sharing-likely caused by intratendinous adhesions-increases between adjacent subtendons. This study quantifies changes in subtendon load sharing 6-12 months following Achilles tendon rupture when patients are cleared by their surgeon to fully return to physical activities. We combined transverse plane ultrasound imaging with neuromuscular electrical stimulation of individual triceps surae muscles and applied a Kanade-Lucas-Tomasi point tracking algorithm to characterize subtendon behavior. We developed a surrogate measure of subtendon load sharing by quantifying differences in point displacement trajectory angles between select regions within the tendon cross section. In patients recovering from rupture injuries (n = 19), subtendon load sharing significantly increased in the injured tendon compared to the contralateral uninjured side during lateral gastrocnemius (p = 0.0094), medial gastrocnemius (p = 0.021), and soleus stimulations (p = 0.048). These differences were not present between right and left legs in the uninjured cohort (n = 17). Linear regression analysis also revealed that the presence of tendon injury was significantly associated with subtendon load sharing, with injured tendons showing up to a 44% decrease in subtendon independence compared to the contralateral uninjured tendon during gastrocnemius stimulations. Statement of Clinical Significance: These results propose a novel biomarker of tendon health and suggest muscle-dependent changes in subtendon function following Achilles tendon rupture.

  PublisherDOI

• Cognitive impairment is associated with poorer oral health in people with HIV: evidence from a pilot study.

  PubMed · 2026-02-27

  articleSenior author

  OBJECTIVE: Despite widespread antiretroviral therapy use, mild and asymptomatic cognitive impairment persists in people with HIV (PWH). Poor oral health is also commonly reported among PWH, yet the prevalence of specific oral diseases in the antiretroviral therapy era remains uncertain. While cognitive impairment has been linked to poor dental outcomes in people without HIV (PWoH), particularly older adults, its impact on oral health in PWH is less understood. This study aimed to compare oral health outcomes in PWH and PWoH; and PWH with and without cognitive impairment. METHOD AND MATERIALS: A cross-sectional pilot study was conducted among 40 participants: 30 PWH and 10 PWoH. Cognitive function was assessed using the Penn Computerized Neurocognitive Battery, and oral health was evaluated through dental caries and periodontitis measures. RESULTS: PWH on average had poorer battery test outcomes (P = .073), with social cognition being the most impaired domain. PWH had significantly worse oral health than PWoH, with higher scores for DMFT (P = .001), DFT (P = .027), and MT (P = .032). Among PWH, those with cognitive impairment exhibited higher DFT scores (median 12.0 vs 7.0) and periodontal inflammation (with respect to bleeding on probing, 51.04% vs 31.67%) compared to those without cognitive impairment. CONCLUSION: Data suggest that PWH demonstrate poorer oral health compared to PWoH. Cognitive impairment in PWH is associated with worse periodontal and caries outcomes. These findings highlight the need for targeted oral health interventions and consideration of cognitive impairment screening in dental care settings for PWH.

  PublisherDOI

• Low prevalence of glomerulonephritis in transplanted kidneys from deceased donors with active hepatitis C virus infection

  Kidney International · 2025-08-22

  articleOpen access

  <h2>Abstract</h2><h3>Introduction</h3> Hepatitis C virus (HCV) infection is a leading cause of immune-complex mediated glomerulonephritis, specifically cryoglobulinemic and membranoproliferative glomerulonephritis, and has also been associated with non-glomerular kidney diseases. However, the prevalence of kidney disease among individuals with chronic HCV infection is unknown. Concerns about the quality of kidneys from deceased donors with HCV infection may lead centers to avoid transplanting these organs. <h3>Methods</h3> We assembled a multicenter histological database of deceased donor biopsies to compare the prevalence of glomerulonephritis and chronic disease pathology among 147 transplanted kidneys from HCV-RNA⁺ donors matched to 431 HCV-negative donors. <h3>Results</h3> The mean age was 40.3 versus 40.7 years for HCV-RNA⁺ versus HCV-negative donors, respectively. Expert pathology reviews showed that glomerular disease and isolated immune complex deposition were rare in both groups. The primary outcome of glomerulosclerosis, interstitial fibrosis with tubular atrophy, and/or vascular disease was non-inferior (15% margin) for HCV-RNA⁺ versus HCV-negative donor kidneys. Specifically, 61.2% versus 49% had under 5% glomerulosclerosis, 68% versus 58% had under 5% interstitial fibrosis with tubular atrophy, and 46% versus 25% had no vascular disease, for HCV-RNA⁺ versus HCV-negative donor kidneys, respectively. The recipients of kidney transplants from HCV-RNA⁺ donors and HCV-negative comparators both demonstrated good graft function and 12-month eGFR was not significantly different between groups (1.65 ml/min/1.73 m² higher eGFR for HCV-RNA⁺ allograft recipients.) <h3>Conclusions</h3> Our findings indicate that for HCV-RNA⁺ donor kidneys, glomerular disease was rare and chronic disease pathology was not more common than among HCV-negative kidneys, which may reassure clinicians to consider these organs for their patients.

  PublisherOA PDFDOI

• High variability in the reported prevalence of EBV-seronegative status among US kidney transplant recipients

  American Journal of Transplantation · 2025-04-29 · 1 citations

  letter
  PublisherDOI

• The Correlation of Total and Functional Warm Ischemic Time of Donation After Circulatory Death Donors with Transplant Kidney Graft Survival

  American Journal of Transplantation · 2025-08-01

  article
  PublisherDOI

• Beyond Fixed Restriction Time: Adaptive Restricted Mean Survival Time Methods in Clinical Trials

  ArXiv.org · 2025-01-25

  preprintOpen access

  Restricted mean survival time (RMST) offers a compelling nonparametric alternative to hazard ratios for right-censored time-to-event data, particularly when the proportional hazards assumption is violated. By capturing the total event-free time over a specified horizon, RMST provides an intuitive and clinically meaningful measure of absolute treatment benefit. Nonetheless, selecting the restriction time $L$ poses challenges: choosing a small $L$ can overlook late-emerging benefits, whereas a large $L$, often underestimated in its impact, may inflate variance and undermine power. We propose a novel data-driven, adaptive procedure that identifies the optimal restriction time $L^*$ from a continuous range by maximizing a criterion balancing effect size and estimation precision. Consequently, our procedure is particularly useful when the pattern of the treatment effect is unknown at the design stage. We provide a rigorous theoretical foundation that accounts for variability introduced by adaptively choosing $L^*$. To address nonregular estimation under the null, we develop two complementary strategies: a convex-hull-based estimator, and a penalized approach that further enhances power. Additionally, when restriction time candidates are defined on a discrete grid, we propose a procedure that surprisingly incurs no asymptotic penalty for selection, thus achieving oracle performance. Extensive simulations across realistic survival scenarios demonstrate that our method outperforms traditional RMST analyses and the log-rank test, achieving superior power while maintaining nominal Type I error rates. In a phase III pancreatic cancer trial with transient treatment effects, our procedure uncovers clinically meaningful benefits that standard methods overlook. Our methods are implemented in the R package AdaRMST.

  PublisherOA PDFDOI

• Long-Term Comparative Effectiveness of Rituximab vs. Calcineurin Inhibitors for the Treatment of Membranous Nephropathy

  Journal of the American Society of Nephrology · 2025-10-01

  article
  PublisherDOI

• The Association of Epstein–Barr Virus Donor and Recipient Serostatus With Outcomes After Kidney Transplantation

  Annals of Internal Medicine · 2025-01-27 · 3 citations

  articleOpen access

  BACKGROUND: Prior studies indicate that 1% to 4% of Epstein-Barr virus (EBV)-seronegative recipients of EBV-seropositive donor (EBV D+/R-) kidneys develop posttransplant lymphoproliferative disorder (PTLD). However, these estimates are based on limited data that lack granularity. OBJECTIVE: To determine the associations between pretransplant EBV D+/R- and recipient EBV-seropositive status (R+) and the outcomes of PTLD and graft and patient survival among adult kidney transplant recipients. DESIGN: Retrospective cohort study. SETTING: Two large U.S. transplant centers. PARTICIPANTS: Epstein-Barr virus D+/R- and EBV R+ recipients matched 1:3 on donor, recipient, and transplant characteristics between 1 January 2010 and 30 June 2022. MEASUREMENTS: Exposure was pretransplant donor and recipient EBV serostatus. The primary outcome was biopsy-proven PTLD. Secondary outcomes were all-cause graft loss (death, retransplant, or graft failure) and death. Follow-up was truncated to 3 years after transplant. RESULTS: The final cohort comprised 104 EBV D+/R- recipients matched to 312 EBV R+ recipients. The mean age was 42 years (SD, 17.1), 59% were living donor transplants, and 95% received thymoglobulin induction. Among EBV D+/R- recipients, 50 (48.1%) developed EBV DNAemia, with a median time of 198 days (IQR, 110 to 282 days) after transplantation. Posttransplant lymphoproliferative disorder occurred in 23 (22.1%) EBV D+/R- recipients at a median of 202 days (IQR, 118 to 317 days) after transplantation. Epstein-Barr virus D+/R- recipients had higher all-cause graft failure (hazard ratio, 2.21 [95% CI, 1.06 to 4.63]); mortality was higher but not statistically significant (hazard ratio, 2.19 [CI, 0.94 to 5.13]). LIMITATION: Two-center study. CONCLUSION: Compared with previous studies, this study showed that EBV D+/R- kidney recipients face a 5- to 10-fold higher cumulative incidence of PTLD. Strategies to mitigate the PTLD risk are urgently needed. PRIMARY FUNDING SOURCE: National Institutes of Health.

  PublisherOA PDFDOI

• Heart Donation and Transplant Recipient Survival Outcomes from Independent versus Hospital-Based Donor Care Units

  The Journal of Heart and Lung Transplantation · 2025-04-01

  articleOpen access
  PublisherOA PDFDOI

• Su2059: SAFETY OF GLP-1 AGONISTS IN PATIENTS UNDERGOING ELECTIVE PROCEDURES REQUIRING ANESTHESIA OR SEDATION.

  Gastroenterology · 2025-05-01

  article
  PublisherDOI

Recent grants

• Methods for the Analysis of Event Processes Arising in Organ Transplantation

  NIH · $4.2M · 2005–2029

Frequent coauthors

• Stanley S.A. Fenton

  University of Toronto

  61 shared

• Robert M. Merion

  University of Michigan–Ann Arbor

  57 shared

• Howard Morrison

  Public Health Agency of Canada

  38 shared

• Pratima Sharma

  University of Michigan–Ann Arbor

  32 shared

• Yang Mao

  Shanghai Electric (China)

  28 shared

• Marie DesMeules

  Public Health Agency of Canada

  28 shared

• Bruce Robinson

  University of Sydney

  28 shared

• Friedrich K. Port

  Arbor Research Collaborative for Health

  25 shared