About

Jun (Jay) Zhu, Ph.D., is a Professor of Microbiology at the University of Pennsylvania's Perelman School of Medicine. His research focuses on bacterial pathogenesis, particularly how pathogenic bacteria sense and respond to their environment. His laboratory studies Vibrio cholerae, the causative agent of cholera, to understand the chemical signals it receives during infection and how these signals influence gene expression and virulence. Zhu's work has identified host-produced small molecules that trigger virulence programs in V. cholerae and has explored the role of quorum sensing in regulating virulence and biofilm formation. Additionally, his research investigates how V. cholerae responds to oxidative and nitrosative stresses during infection. His team employs genetic screens, biochemical techniques, animal models, and deep sequencing to probe these mechanisms. Zhu has also extended his expertise to study Clostridium difficile, aiming to shed light on its pathogenesis and identify potential treatment strategies. His contributions advance understanding of host-pathogen interactions and bacterial adaptation during infection.

Research topics

• Medicine
• Nursing
• Environmental health
• Internal medicine
• Finance
• Business
• Physical therapy
• Family medicine
• Economics
• Marketing
• Actuarial science

Selected publications

• Abstract MPTU23: A Payor-Supported, Post-Discharge Medically Tailored Meal Intervention Reduces Readmissions and Medical Spending in Medicare Advantage Members

  Circulation · 2026-03-24

  article

  Background: Medically tailored meals (MTMs) are an emerging strategy to improve access to evidence-based nutrition, support recovery, and prevent avoidable readmissions for older adults in the post-acute period. In alignment with the AHA Health Care by Food™ initiative, scaling MTM programs requires robust systems to identify eligible members, coordinate timely interventions, and measure their real-world clinical and economic impact. Objective: To describe outcomes of a payor-supported, post-discharge MTM supplemental benefit for Medicare Advantage (MA) members of a large national health plan. It was hypothesized that MTM recipients would have relatively lower utilization and expenditures than non-recipients. Methods: Interoperable administrative claims and vendor data identified MA members discharged to home following acute inpatient hospitalization in 2023 with 6-mo continuous coverage. MTM-eligible members were contacted within 3–5 days post-discharge and offered MTMs tailored to dietary and clinical needs. Meal quantity varied by plan design and member preference. A propensity score–matched (PSM) cohort design with difference-in-difference analysis compared 3-mo pre- and post-discharge outcomes between MTM recipients and matched members who declined MTMs. Supplementary analyses evaluated outcomes by meal volume (≤14, >14 meals). Results: Of 276,226 MTM-eligible members, 113,498 (41.1%) opted in. The final study sample included 103,684 PSM members (51,842 per cohort; mean age 73.6y; 55% female; hypertension [87%], diabetes mellitus [41.9%], and heart failure [37.5%]). At 3-mo post-discharge, MTM recipients had relatively fewer 30-day all-cause readmissions (−2.8 per thousand per member, PTPM), inpatient visits (−62.2 PTPM), and lower total medical spend (−$507.81 per member per month; all P<.001). Utilization and spend were relatively lower among members receiving ≤14 (all P<.001), with mixed findings for >14 meals. Conclusions: A data-informed implementation model enabled timely identification, engagement, and scaled delivery of a MTM benefit to support MA members residing across the US. MTM receipt was associated with favorable differences in 30-day all-cause readmissions, inpatient visits, and medical spend, with variable results by meal volume. Findings may inform policy efforts to advance integration of nutrition-based interventions in post-acute care pathways and emphasize the value of multi-stakeholder coordination across the health care ecosystem.

  PublisherDOI

• Abstract MPTU21: Proactive Outreach May Mitigate Disengagement in Electronic Healthy Eating Interventions: A Qualitative Study

  Circulation · 2026-03-24

  article

  Background: The US population eats less than recommended amounts of fruit and vegetables (F&V). We conducted a randomized clinical trial to test whether a $160 monthly F&V subsidy, choice architecture (F&V shown first on the online store), and/or text message reminders of the subsidy balance increased F&V purchases in an online grocery store over 3 months. We conducted interviews with high and low spending participants to understand their experiences. Methods: Using data on participants’ subsidy expenditures, we recruited respondents from the top and bottom 30% of average monthly expenditures among those in the intervention arm for the three months they participated. Participants were invited to brief telephone interviews that asked about their experience in the program, benefits, challenges, and program impact. Interviews were conducted March - May 2025, recorded, transcribed, and blinded. Two researchers summarized transcript responses. After all data were summarized, responses were unblinded, analyzed, and compared by group. Results: We conducted 41 interviews with 23 high spenders and 18 low spenders (N=187). Respondents were primarily Black, female, and over 50 years of age. High spenders described the program as easy to use, motivating, and enjoyable. They liked the convenience of selecting eligible items, tracking balances, and having groceries delivered. The program enhanced access to F&V while fitting into existing routines and helping participants save time. They also appreciated features such as reminder texts and the $25 sign-up incentive. Some high spenders reported difficulties using the site but proactively reached out for support and found solutions. Low spenders struggled with adoption, often due to technical or payment barriers. Confusion around the site, digital subsidy, and competing payment methods (e.g., SNAP or debit cards) discouraged participation. These participants frequently expressed frustration and reported abandoning attempts to use the subsidy. They emphasized the need for greater communication and troubleshooting support from the study team. Conclusion: While many high spenders found the program motivating and easy to use, lower spenders were often discouraged by technological barriers such as confusion with payment systems. Interventions that include an electronic component should consider proactive outreach to help mitigate these challenges and support full engagement.

  PublisherDOI

• A pilot randomized clinical trial of gamification to increase medication adherence

  American Heart Journal · 2026-03-07

  articleOpen access

  INTRODUCTION: Medication nonadherence is a key contributor to poor control of cardiovascular risk factors, but most interventions shown to increase adherence are labor-intensive and have not been implemented widely. Gamification interventions informed by behavioral economic theory increase physical activity with minimal cost and personnel requirements. We tested the feasibility of a gamification intervention to increase medication adherence among patients at risk of cardiovascular disease with a history of medication nonadherence. METHODS: Patients seen in a single primary care clinic who were prescribed 1 or 2 antihypertensive medications and a statin and had a recent history of nonadherence were identified and offered enrollment in a pilot randomized controlled trial. Patients were enrolled on the Penn Way to Health platform, provided with a validated home blood pressure cuff, and randomized to attention control or gamification. Attention control patients received daily text messages asking if they took their antihypertensive medication and statin, and biweekly text messages asking them to check and report their blood pressure. Gamification participants received the same text messages, and were also enrolled in a game in which they were provided with 90 points per week and lost 10 points each day they did not report taking their antihypertensive medications or statin and each time they did not report a blood pressure when requested. Each week, participants with 70 points or more moved up a level; those with less than 70 points moved down a level. The intervention continued for 14 weeks, followed by a 4-week post-intervention follow-up period. The trial's primary outcome was self-reported adherence. RESULTS: A total of 622 patients were eligible for the study and were contacted by study staff; ultimately 43 (of a planned 84) were enrolled and randomized to gamification (n = 21) or control (n = 22). Mean (SD) age was 65 (7.2), 20 (46.5%) were women, and 25 (58.1%) were Black. Over the 18-week study period, there was no significant difference between arms in adherence to antihypertensive medications (79.6% [gamification] vs. 78.6% [control]; difference between arms, 1.4%, 95% CI -1.2 to 3.9%) or statins (80.4% [gamification] vs. 78.6% [control]; difference between arms, 1.8%, 95% CI -2.2 to 5.9%). There were no differences in self-reported adherence between arms over the post-intervention follow-up period, and similarly no differences between arms in medication adherence by SureScripts data, systolic blood pressure, or low-density lipoprotein cholesterol. CONCLUSIONS: In this pilot randomized controlled trial, we found that a behaviorally-designed gamification intervention did not increase adherence to antihypertensive medications and statins compared with attention control. Challenges with recruiting patients with a history of poor adherence and lack of tools for automated, inexpensive, unobtrusive measurement of daily medication-taking behavior are key limitations to the deployment of gamification to increase medication adherence. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov; unique identifier: NCT05326386.

  PublisherDOI

• What motivates participants: a qualitative analysis of gamification and financial incentives to increase physical activity

  BMC Public Health · 2025-05-16 · 2 citations

  articleOpen access

  BACKGROUND: Physical activity reduces the risk of major cardiovascular events, but many people who are most at-risk do not get enough exercise. In the BE ACTIVE randomized controlled trial, - a study in which text messages were used to communicate with participants- game playing (gamification), financial incentives, and the combination of gamification plus financial incentives increased physical activity from baseline more than control over a 12-month intervention period. Participants randomized to gamification plus financial incentives maintained a significantly greater increase than control over the 6-month post-intervention follow-up. To understand the impact of the interventions on motivation and performance we conducted semi-structured interviews with a subset of participants. METHODS: Using extreme case sampling, interviewees were selected from participants who were randomized to an intervention arm and were identified as either high or low performers based on their change from baseline to the end of the trial in mean daily step count. During semi-structured telephone interviews, participants were asked their thoughts and feelings about the trial, motivations for participation, and about specific aspects of the intervention. Interviews were conducted within 6 months after the participant completed participation in the trial. Thematic analysis was conducted inductively and deductively, and identified themes were mapped onto the COM-B Framework to understand the interaction between different themes. RESULTS: We achieved saturation after conducting interviews with 55 participants (30 high performers and 25 low performers); 19 in the gamification arm, 19 in the financial incentives arm, and 17 in the gamification plus financial incentives arm. Based on qualitative interviews, the importance of individual accountability via goal setting and feedback appears to be a primary factor in behavior change in this trial; however, the combination of accountability with the opportunity of access to the intervention had additional impact on the results. CONCLUSION: Gamification and financial incentives both increased physical activity in the BE ACTIVE study, but results may be improved by tailoring interventions based on participants' personal traits and level of social support to optimize motivation. (328 words) TRIAL REGISTRATION: NCT03911141 Registration date: 04/09/2019.

  PublisherOA PDFDOI

• Behaviorally Designed Gamification and Physical Activity Among Breast and Prostate Cancer Survivors

  JACC CardioOncology · 2025-11-05 · 5 citations

  articleOpen access

  BACKGROUND: Black and Hispanic cancer survivors exposed to cardiotoxic therapies are at higher risk for cardiovascular events than non-Hispanic White survivors, attributed to greater cardiovascular risk factors and lower physical activity. OBJECTIVES: This study sought to determine the effect of a remotely delivered and behaviorally designed gamification intervention vs attention control on physical activity in Black and Hispanic cancer survivors with cardiovascular risk factors. METHODS: Between May 2022 and February 2025, Black and Hispanic breast and prostate cancer survivors who had received cardiotoxic cancer therapy and had ≥1 cardiovascular risk factor were enrolled in a randomized clinical trial with a 24-week intervention and 12-week postintervention period. Participants received a wearable device to track daily steps, established a baseline, selected a step goal increase, and were assigned to attention control (n = 76) or gamification (n = 74). The primary outcome was change in mean daily steps from baseline through the intervention period. RESULTS: Mean participant age was 64 years; 81% women, 64% Black, and 35% Hispanic. Gamification arm participants had a greater change from baseline in mean daily steps than control participants during the intervention period (+759; 95% CI: 209-1,309; P = 0.007) and follow-up (+581; 95% CI: -47 to 1,208; P = 0.070), and a greater increase in weekly minutes of moderate-vigorous physical activity during intervention (+16; 95% CI: 4-29; P = 0.010) and follow-up (+11; 95% CI: 0-22; P = 0.048). CONCLUSIONS: Gamification increased physical activity compared with attention control in Black and Hispanic cancer survivors, and represents a scalable intervention to reduce cardiovascular risk in this high-risk population (RCT of Strategies to Augment Physical Activity in Black and Hispanic Breast and Prostate Cancer Survivors [ALLSTAR]; NCT05176756).

  PublisherDOI

• Savings Associated With Bundled Payments for Outpatient Spine Surgery Among Medicare Beneficiaries

  JAMA Health Forum · 2025-07-11 · 2 citations

  articleOpen access

  Importance: Few value-based payment programs have targeted outpatient surgery, although these procedures comprise most surgeries performed in hospitals. In 2018, the Centers for Medicare and Medicaid Services introduced Bundled Payments for Care Improvement Advanced (BPCI Advanced), the first episode-based payment model to include an outpatient surgical condition-spine surgery. It is not known whether bundled payments reduce spending or improve quality for outpatient surgery, despite plans to expand outpatient episodes in future models. Objective: To determine whether hospital participation in the first year of BPCI Advanced for outpatient and inpatient spine surgery (back and neck except spinal fusion procedures [BNESF]) was associated with changes in spending and quality. Design, Setting, and Participants: A retrospective cohort study using Medicare claims and differences-in-differences analysis adjusting for patient and market characteristics was conducted comparing outcomes for patients receiving outpatient and inpatient BNESF from hospitals that participated in BPCI Advanced vs those receiving these procedures from a matched comparison group of nonparticipating hospitals. Medicare beneficiaries receiving outpatient and inpatient BNESF between 2013 and 2019 were included. Analyses were conducted between March 2023 and February 2024. Exposures: Hospital participation in BPCI Advanced. Main Outcomes and Measures: The primary outcome was total episode spending, including spending incurred for the index procedure and 90-day follow-up period. Secondary outcomes included 90-day return inpatient admissions, emergency department visits, and mortality. Results: Among 14 280 patients who received outpatient BNESF, hospital participation in BPCI Advanced was associated with a differential reduction in total episode spending (-$1201; 95% CI, -2184 to -219) and return inpatient admissions (-2.2 percentage points; 95% CI, -4.2 to -0.1). For outpatient procedures, the mean (SD) age was 71.8 (8.6) years; 43.9% were women, 3.9% were Black; and 3.2% were Hispanic. Among 23 440 patients who received inpatient BNESF, hospital participation in BPCI Advanced was not associated with differential changes in total episode spending or return inpatient admissions. There were no significant changes for emergency department visits or mortality for either group. Conclusions and Relavance: In this cohort study, participation in the first year of a bundled payment program for outpatient spine surgery was associated with nearly 10% lower spending. No changes in spending were observed for similar inpatient spine surgery procedures. Further evaluation of bundled payments for outpatient surgical conditions and associated changes in care delivery is needed to inform plans to include these episodes in future models.

  PublisherDOI

• Physician and Hospital Performance in Medicare’s Updated Bundled-Payment Model for Joint Replacement

  JAMA Health Forum · 2025-07-25 · 2 citations

  articleOpen access

  Importance: Independent evaluations of Bundled Payments for Care Improvement Advanced (BPCI-A) have focused on hospitals and have not assessed the performance of physicians in participating physician group practices (PGPs). However, PGPs are accountable for a larger proportion of surgical procedures, including for lower-extremity joint replacement, in the BPCI-A model than are hospitals. Objective: To evaluate the association of treatment by BPCI-A-participating physicians and hospitals with health care spending, quality, and utilization for joint replacement procedures compared to nonparticipants. Design, Setting, and Participants: This cohort study used Medicare claims of beneficiaries receiving lower-extremity joint replacement between April 2016 and September 2019 and data on BPCI-A-participating PGPs and hospitals to assess spending, quality, and utilization. Differences-in-differences methods adjusting for patient and market characteristics (aDID) were used with matched comparison groups of nonparticipating physicians and hospitals. Data analysis was performed from January 2023 to January 2025. Exposures: Lower-extremity joint replacement by a physician in a PGP or hospital that began BPCI-A participation in October 2018. Main Outcomes and Measures: Ninety-day total episode spending for joint replacement. Secondary outcomes were postacute care utilization, mortality, hospital readmissions, and joint replacement complications. Results: The matched cohort included 846 529 Medicare beneficiaries (mean [SD] age, 73.7 [8.3] years; 63.8% female) who obtained a joint replacement in April 2016 to September 2019, of whom 281 189 were treated by 2820 physicians in BPCI-A-participating PGPs, and 69 107 by 174 BPCI-A-participating hospitals. An additional 28 309 beneficiaries were treated by physicians and hospitals both participating in BPCI-A. The remaining 467 924 were treated by 4671 nonparticipating physicians and 432 nonparticipating hospitals. Before BPCI-A participation, total unadjusted baseline episode spending was $26 483 for participating physicians and $29 854 for participating hospitals. Treatments by BPCI-A participating physicians and hospitals were each associated with differentially lower total spending (physician aDID, -$855; 95% CI, -$1074 to -$636; hospital aDID, -$613; 95% CI, -$1039 to -$187). Treatment by a BPCI-A-participating physician or hospital was associated with differentially lower institutional postacute care utilization. Physician participation was associated with a differential increase in outpatient visits 7 days postdischarge (aDID, 2.9 percentage points; 95% CI, 2.0 to 3.8), while hospital participation was not associated with a change in outpatient visits. Differential changes in mortality, readmissions, and complications were not observed for either participant type. Conclusions and Relevance: This cohort study found that participation in BPCI-A for joint replacement was associated with differentially lower total spending for both physicians and hospitals. Given that physicians in PGPs accounted for 73% of all the joint replacement episodes, these findings highlight the importance of facilitating alignment between hospitals and physicians in future bundled-payment models, including those that allow only hospitals.

  PublisherOA PDFDOI

• Abstract 4359940: Behaviorally-Designed Gamification Increases Physical Activity Among Breast and Prostate Cancer Survivors: The ALLSTAR Randomized Clinical Trial

  Circulation · 2025-11-03

  article

  Background: Breast and prostate cancer survivors are at high risk of cardiovascular events due to cardiotoxic therapies. Physical activity is associated with better outcomes in these patients, but most do not meet targets. Black and Hispanic cancer survivors are at higher risk for cardiovascular events and are less active than non-Hispanic White survivors. Methods: This was a pragmatic randomized controlled trial evaluating the effectiveness of a remotely delivered gamification intervention to increase daily physical activity in Black and Hispanic breast and prostate cancer survivors who had received cardiotoxic therapy and had at least 1 additional cardiovascular risk factor. Patients were mailed a wearable device to track daily steps, established a baseline daily step count, set a goal to increase daily step count by 1500-3000/day, and were randomized to control (n=76) or gamification (n=74). The gamification group was entered into a 24-week game designed using insights from behavioral economics with points and levels for achieving step goals. The intervention included a 12-week follow-up period to evaluate sustainability of behavior. The control group received feedback from the wearable device but no other interventions for 36 weeks. The primary outcome was change from baseline in daily steps through the end of the 24-week intervention period. Results: A total of 150 patients (mean age, 64 years; 81% female, 64% Black, 35% Hispanic, 60% hypertension, 51% hyperlipidemia, 44% obesity, 28% diabetes; mean time since cancer diagnosis, 7.8 years) were enrolled from 2 health systems. Mean±SD daily step count increase from baseline through the end of the intervention period was 983±1539 in the control arm and 1757±1921 in the gamification arm ( Figure ). Compared with controls, gamification participants had a significantly greater increase from baseline in mean daily steps during the intervention period (+770, 95% CI 217 to 1323, P = 0.006), which persisted during follow-up (+596, 95% CI -30 to 1223, P = 0.06). Gamification also increased weekly minutes of moderate to vigorous physical activity more than control (intervention period: +16, 95% CI 4 to 29, P =0.01; follow-up: +11, 95% CI 0 to 21, P = 0.05). Conclusion: Remotely delivered gamification increased daily physical activity from baseline more than control in breast and prostate cancer survivors, and may represent a scalable intervention to reduce cardiovascular risk in this high-risk population.

  PublisherDOI

• Effect of Gamification Plus Automated Coaching to Increase Physical Activity Among Patients With Peripheral Artery Disease: The GAMEPAD Randomized Controlled Trial

  Journal of the American Heart Association · 2025-12-03 · 4 citations

  articleOpen access

  Background Supervised exercise therapy improves walking performance in patients with peripheral artery disease (PAD), but few participate. Interventions leveraging concepts from behavioral economics increase physical activity in patients at high cardiovascular risk, but barriers to physical activity differ in patients with PAD. Methods In this randomized controlled trial, conducted from October 2020 through January 2024, patients with PAD were provided with a wearable fitness tracker, established a baseline daily step count, and set a step goal increase. They were randomly assigned to attention control or to gamification. The control group received feedback from the fitness tracker but no other interventions for 24 weeks. The gamification group was entered into a 16‐week game designed using insights from behavioral economics and received educational text messages. No intervention occurred during an 8‐week postintervention follow‐up period. Results A total of 103 patients (mean age, 70±9 years; 54 [52%] men, 74 (72%) with exertional lower extremity symptoms) were randomized to attention control (n=52) or gamification (n=51). Compared with controls, gamification participants had a greater increase in mean daily steps from baseline during the intervention period (adjusted difference, 920 [95% CI, −22 to 1861]; P =0.06) that became statistically significant during the follow‐up period (adjusted difference, 1074 [95% CI, 133–2015]; P =0.03). Conclusions In this randomized clinical trial, gamification increased physical activity compared with attention control over a 24‐week follow‐up. This intervention may represent a scalable approach for increasing physical activity in patients with PAD who are not able to participate in supervised exercise therapy. Registration URL: https://clinicaltrials.gov/study/NCT04536012 ; Unique Identifier: NCT04536012.

  PublisherDOI

• Cost-Effectiveness of Gamification, Financial Incentives, or Both to Increase Physical Activity Among Patients With Elevated Risk for Cardiovascular Disease

  Circulation Cardiovascular Quality and Outcomes · 2025-06-17 · 3 citations

  article

  BACKGROUND: The BE ACTIVE trial (Behavioral Economic Approaches to Increase Physical Activity Among Patients with Elevated Risk for Cardiovascular Disease) documented the effectiveness, compared with an attention control arm that received daily text messages, of gamification, financial incentives, or gamification+financial incentives to increase steps/day. Increases in daily step count are associated with longer life expectancy, but understanding the cost-effectiveness of these interventions is essential for payers and other stakeholders seeking to implement findings. METHODS: We built a probabilistic Markov model to compare intervention costs with lifetime estimates of life-years and quality-adjusted life-years for 2 sets of comparisons: (1) each behavioral intervention versus attention control, and (2) each trial arm, including attention control, versus no intervention. Since the durability of changes in steps/day post-intervention is unknown, we modeled optimistic, intermediate, and pessimistic scenarios. RESULTS: Over the 12-month intervention, per-participant cost to deliver attention control was $878, gamification $938, financial incentives $1534, and gamification+financial incentives $1712. Compared with attention control, gamification's cost-effectiveness ranged from $261 (95% CI, 259-263) per life-year gained if mean steps/day during the last 18 weeks of follow-up are maintained (optimistic), to $30 550 (95% CI, 30 503-30 597) per life-year if steps/day continue to decline at the rate observed during the full 26-week follow-up (pessimistic). Gamification+financial incentives cost <$50 000/life-year only under the optimistic and intermediate scenarios. Financial incentives was dominated by gamification and gamification+financial incentives. When all 4 trial arms, including attention control, were compared with no intervention, gamification again cost <$50 000/life-year across all durability scenarios. CONCLUSIONS: Across a range of scenarios about the durability of increases in steps/day post-intervention, gamification consistently cost <$50 000 per life-year gained, the threshold for high value interventions set by American College of Cardiology/American Heart Association guidelines. Gamification+financial incentives was high-value except in the pessimistic scenario. Financial incentives was dominated. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03911141.

  PublisherDOI

Frequent coauthors

• Kevin G. Volpp

  University of Pennsylvania

  260 shared

• David A. Asch

  95 shared

• Judy A. Shea

  92 shared

• Amol S. Navathe

  University of Pennsylvania

  72 shared

• Robert Galvin

  69 shared

• Annice Kim

  Southern Federal University

  66 shared

• Jeanette M. Renaud

  Laboratoire Dr Renaud

  64 shared

• Angela Towers

  Manchester Metropolitan University

  64 shared

Education

• B.S., Microbiology

  Wuhan University

  1991

• Ph.D., Microbiology

  Cornell University

  1999