Xiao Zang

University of Minnesota Twin Cities | UMN

Importance In 2021, the state of Rhode Island distributed 10 000 additional naloxone kits compared with the prior year through partnerships with community-based organizations. Objective To compare various strategies to increase naloxone distribution through community-based programs in Rhode Island to identify one most effective and efficient strat...

Objective: Despite their effectiveness in preventing the transmission of HIV among people who inject drugs (PWID), syringe services programs (SSPs) in many settings are hampered by social and political opposition. We aimed to estimate the impact of closure and temporary interruption of SSP on the HIV epidemic in a rural US setting. Methods: Usin...

Background: Understanding the sources of HIV transmission provides a basis for prioritizing HIV prevention resources in specific geographic regions and populations. This study estimated the number, proportion, and rate of HIV transmissions attributable to individuals along the HIV care continuum, within different HIV transmission risk groups in si...

Background Rates of fatal opioid overdose in Massachusetts (MA) and Rhode Island (RI) far exceed the national average. Community-based opioid education and naloxone distribution (OEND) programs are effective public health interventions to prevent overdose deaths. We compared naloxone distribution and opioid overdose death rates in MA and RI to iden...

Objectives The ambitious goals of the US Ending the HIV Epidemic initiative will require a targeted, context-specific public health response. Model-based economic evaluation provides useful guidance for decision making while characterizing decision uncertainty. We aim to quantify the value of eliminating uncertainty about different parameters in se...

Background The US Ending the HIV Epidemic (EHE) initiative aims to reduce national HIV incidence 90% by 2030 and to address the disproportionate burden of HIV among different racial/ethnic populations. Florida's state-wide 2022–2026 Integrated HIV Prevention and Care Plan outlines objectives for reaching EHE goals. In Miami-Dade County, we determin...

Introduction We evaluated racial/ethnic differences in the receipt of naloxone distributed by opioid overdose prevention programs (OOPPs) in New York City (NYC). Methods We used naloxone recipient racial/ethnic data collected by OOPPs from April 2018 to March 2019. We aggregated quarterly neighborhood-specific rates of naloxone receipt and other c...

Background: Systems to track fatal and non-fatal overdoses rely on medical services to provide information about overdoses, which only capture overdoses in which medical care is provided. In the state of Missouri, the Overdose Field Report (ODFR) is a community-based reporting system which allows medical and lay responders to report overdoses they...

Background and Aims The onset of the coronavirus disease 2019 (COVID‐19) pandemic was associated with a surge in opioid overdose deaths in Massachusetts, particularly affecting racial and ethnic minority communities. We aimed to compare the impact of the pandemic on opioid overdose fatalities and naloxone distribution from community‐based programs...

Background Despite significant progress in HIV treatment and prevention, the US remains far from its goal of ‘Ending the HIV Epidemic’ by 2030. Economic models using local data can synthesise the evidence to help policymakers allocate HIV resources efficiently, but persistent research-to-practice gaps remain. Little is known about how to facilitate...

Introduction Given the ageing epidemic of tuberculosis (TB), China is facing an unprecedented opportunity provided by the first clinically approved next-generation TB vaccine Vaccae, which demonstrated 54.7% efficacy for preventing reactivation from latent infection in a phase III trial. We aim to assess the population-level health and economic imp...

Introduction: We evaluated racial/ethnic differences in the receipt of naloxone distributed by opioid overdose prevention programs (OOPPs) in New York City (NYC). Methods: We used naloxone recipient racial/ethnic data collected by OOPPs from April 2018 to March 2019. We aggregated quarterly neighborhood-specific rates of naloxone receipt and other...

Data from several modeling studies demonstrate that large-scale increases in HIV testing across settings with a high burden of HIV may produce the largest incidence reductions to support the US Ending the HIV Epidemic (EHE) initiative's goal of reducing new HIV infections 90% by 2030. Despite US Centers for Disease Control and Prevention's recommen...

Background Overdose deaths have increased dramatically in the United States, including in Rhode Island. In July 2021, the Rhode Island government passed legislation supporting a two-year pilot program authorizing supervised consumption sites (SCSs) in response to this crisis. We estimated the costs and benefits of a hypothetical SCS in Providence,...

Background Racial/ethnic minorities have experienced disproportionate opioid-related overdose death rates in recent years. In this context, we examined inequities in community-based naloxone access across racial/ethnic groups in Massachusetts. Methods We used data from: the Massachusetts Department of Public Health on community-based overdose educ...

Background: Despite recent HIV outbreaks among people who inject drugs (PWID) in nonurban US settings, syringe service programs (SSP) are often inaccessible in these communities. Furthermore, pre-exposure prophylaxis (PrEP) awareness and coverage for PWID is limited. We aimed to model the impact of PrEP on HIV transmission among PWID in a rural se...

Introduction Productivity loss may contribute to a large proportion of costs of health conditions in an economic evaluation from a societal perspective, but there is currently a lack of methodological consensus on how productivity loss should be measured and valued. Despite the research progress surrounding this issue in other countries, it has bee...

Objectives China suffers from high burdens of human papillomavirus (HPV) and cervical cancer, whereas the uptake of HPV vaccine remains low. The first Chinese domestic HPV vaccine was released in 2019. However, collective evidence on cost-effectiveness of HPV vaccination in China has yet to be established. We summarised evidence on the cost-effecti...

Background and aims Opioid-related overdose death rates continue to rise in the United States, especially in racial/ethnic minority communities. Our objective was to determine if US municipalities with high percentages of non-white residents have equitable access to the overdose antidote naloxone distributed by community-based organizations. Metho...

Background In the USA, Black and Hispanic or Latinx individuals continue to be disproportionately affected by HIV. Applying a distributional cost-effectiveness framework, we estimated the cost-effectiveness and epidemiological impact of two combination implementation approaches to identify the approach that best meets the dual objectives of improvi...

Objective: Combination strategies generate health benefits through improved health outcomes among people living with HIV (PLHIV) and prevention of new infections. We aimed to determine health benefits attributable to improved health among PLHIV versus HIV prevention for a set of combination strategies in six US cities. Design: A dynamic HIV tran...

Opioid agonist treatment (OAT) is the evidence‐based standard of care for people with opioid use disorder. In British Columbia, Canada, only social assistance registrants received full coverage for OAT prior to the introduction of the Pharmacare Plan G coverage expansion on February 1st, 2017. We aimed to determine the effect of the coverage expans...

Introduction: The Chinese government has established a nationwide community-based chronic disease management program since 2009 with hypertension a vital part of it. Though drugs have been proven effective with hypertensive patients, they bring economic burden as well, especially for those who with elevated blood pressure and are potentially eligib...

Background : People who inject drugs (PWID) are at elevated risk for HIV infection; however, syringe services programs (SSPs) are effective in curtailing HIV transmission. Despite their effectiveness, SSPs in many settings are hampered by social and political opposition. We aimed to estimate the impact of closure and temporary interruption of SSP s...

Background Although there is ongoing debate over the need for substantial increases in PrEP use when antiretroviral treatment confers the dual benefits of reducing HIV-related morbidity and mortality and the risk of HIV transmission, no studies to date have quantified the potential added benefits of PrEP use in settings with high treatment engageme...

Health economic evaluations provide guidance for allocating resources and improving health outcomes. In low-and middle-income countries with limited health resources such as China, economic evaluation should have a more significant role than it does. However, several practical issues may hamper the development of economic evaluations in China, incl...

Although there is ongoing debate over the need for substantial increases in pre-exposure prophylaxis (PrEP) use when antiretroviral treatment confers the dual benefits of reducing HIV-related morbidity and mortality and the risk of HIV transmission, no studies to date have quantified the potential added benefits of PrEP use and changes in its effic...

Background Widespread viral and serological testing for SARS-CoV-2 may present a unique opportunity to also test for HIV infection. We estimated the potential impact of adding linked, opt-out HIV testing alongside SARS-CoV-2 testing on HIV incidence and the cost-effectiveness of this strategy in six US cities. Methods Using a previously-calibrated...

Background: Persons who inject drugs (PWID) are at a disproportionately high risk of HIV infection. We aimed to determine the highest-valued combination implementation strategies to reduce the burden of HIV among PWID in 6 US cities. Methods: Using a dynamic HIV transmission model calibrated for Atlanta, Baltimore, Los Angeles, Miami, New York C...

Using a dynamic HIV transmission model calibrated for 6 US cities, we projected HIV incidence from 2020-2040 and estimated whether an established UNAIDS HIV epidemic control target could be met under ideal implementation of optimal combination strategies previously defined for each city. Four of six cities (Atlanta, Baltimore, New York City, and Se...

We estimated HIV incidence and incidence rate ratios (IRR) for Blacks and Hispanics versus Whites in six US cities (2020-2030). Large reductions in incidence are possible, but without elimination of disparities in healthcare access, we found wide disparities for Blacks to Whites in particular persisted (lowest IRR:1.69[95%CrI,1.19-2.30]).

Background The HIV epidemic in the USA is a collection of diverse local microepidemics. We aimed to identify optimal combination implementation strategies of evidence-based interventions to reach 90% reduction of incidence in 10 years, in six US cities that comprise 24·1% of people living with HIV in the USA. Methods In this economic modelling stu...

Background. Heterogeneity in HIV microepidemics across US cities necessitates locally oriented, combination implementation strategies to prioritize resources. We calibrated and validated a dynamic, compartmental HIV transmission model to establish a status quo treatment scenario, holding constant current levels of care for 6 US cities. Methods. Bui...

Objective: Effective interventions to reduce the public health burden of HIV/AIDS can vary in their ability to deliver value at different levels of scale and in different epidemiological contexts. Our objective was to determine the cost-effectiveness of HIV treatment and prevention interventions implemented at previously documented scales of deliv...

We estimated 10-year (2020-2030) trajectories for HIV incidence in six US cities. Estimated incidence will only decrease in two of six cities, with the overall population-weighted incidence decreasing 3.1% [-1.0% - 8.5%] by 2025, and 4.3% [-2.6% - 12.7%] by 2030 across cities. Targeted, context-specific combination implementation strategies will be...

Background: The synthetic control method (SCM) is a useful tool in providing unbiased analysis on the policy effect in real-world health policy evaluations. Through controlling for a few confounding factors, we aim to apply SCM in analyzing the impact of the pricing reform on medical expenditure structure in Jiangsu Province, China. Methods: We...

Born out of a necessity for fiscal sustainability, simulation modeling is playing an increasingly prominent role in setting priorities for combination implementation strategies for HIV treatment and prevention globally. The design of a model and the data inputted into it are central factors in ensuring credible inferences. We executed a narrative r...

Background Dynamic HIV transmission models can provide evidence-based guidance on optimal combination implementation strategies to treat and prevent HIV/AIDS. However, these models can be extremely data intensive, and the availability of good-quality data characterizing regional microepidemics varies substantially within and across countries. We ai...

With efficacious behavioral, biomedical, and structural interventions available, combination implementation strategies are being implemented to combat HIV/AIDS across settings internationally. However, priority statements from national and international bodies make it unclear whether the objective should be the reduction in HIV incidence or the max...

Background: Suboptimal retention is among the biggest challenges to realize the full benefits of combination antiretroviral therapy (ART). We aimed to describe ART interruption patterns and identify determinants of disease progression while off ART in British Columbia, Canada. Methods: With population-level data on ART utilization and laboratory...

Background: Recognition of the secondary preventive benefits of antiretroviral therapy (ART) has mobilized global efforts to 'seek, test, treat and retain' people living with HIV/AIDS (PLHIV) in HIV care. We aimed to determine the cost-effectiveness of a set of HIV testing and treatment engagement interventions initiated in British Columbia (BC),...

Background: Antiretroviral therapy (ART) and harm reduction services have been cited as key contributors to control of HIV epidemics; however, the specific contribution of ART has been questioned due to uncertainty of its true efficacy on HIV transmission through needle sharing. We aimed to isolate the independent effects of harm reduction service...

Background: In Guangxi Zhuang Autonomous Region, China, an estimated 80% of newly-identified antiretroviral therapy (ART)-eligible patients are not engaged in ART. Delayed ART uptake ultimately translates into high rates of HIV morbidity, mortality, and transmission. To enhance HIV testing receipt and subsequent treatment uptake in Guangxi, the Ch...