Hang T Pham

All Publications

• Cost-Effectiveness of One-time Universal Testing for Hepatitis D among Adults living with Chronic Hepatitis B in the United States. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America Toy, M., Hutton, D., Teshale, E., Thompson, W. W., Pham, H., Salomon, J. A., So, S. 2025

  Abstract

  Chronic hepatitis D virus (HDV) infection increases the risk of liver-related deaths in adults with chronic hepatitis B (CHB). In the US, only an estimated 12.9% of adults with CHB have received an HDV antibody test. The aim of this study is to calculate the cost-effectiveness of one-time universal HDV testing of hepatitis B surface antigen (HBsAg)-positive adults living in the US.A Markov model was used to calculate the costs, health impact, and cost-effectiveness of universal testing of HBsAg- positive adults with an HDV antibody test and, when positive, an HDV RNA test for chronic HDV infection. We assumed 50% of the HDV RNA positive patients would receive the current recommended treatment with pegylated interferon (PEG-IFN) for 48 weeks. With a 30% response rate. We also modelled the potential impact of hypothetical indefinite HDV antiviral therapy with a higher response rate to assess the annual cost threshold to be considered cost-effective.Universal HDV testing of adults with CHB could avert 100 HDV-related deaths and an additional 30 cases of cirrhosis and 50 cases of hepatocellular carcinoma, and potentially result in a gain of 1,500 QALYs per 100,000 HBsAg-positive individuals screened. At a willingness to pay threshold of $50,000/QALY, the annual drug costs for a hypothetical indefinite therapy with a 50% or 70% treatment response rate would need to cost ≤ $13,027 and $14,104, respectively.One-time HDV testing for all HBsAg-positive adults and treatment of chronic HDV infection with PEG-INF is potentially cost effective in the US.

  View details for DOI 10.1093/cid/ciaf181

  View details for PubMedID 40198094

• Cost-effectiveness of monitoring and liver cancer surveillance among patients with inactive chronic hepatitis B. PloS one Toy, M., Hutton, D., Conners, E. E., Pham, H., Salomon, J. A., So, S. 2025; 20 (1): e0313898

  Abstract

  Patients with chronic hepatitis B infection (CHB) have an increased risk for death from liver cirrhosis and hepatocellular carcinoma (HCC). In the United States, only an estimated 37% of adults with chronic hepatitis B diagnosis without cirrhosis receive monitoring with at least an annual alanine transaminase (ALT) and hepatitis B deoxyribonucleic acid (DNA), and an estimated 59% receive antiviral treatment when they develop active hepatitis or cirrhosis. A Markov model was used to calculate the costs, health impact and cost-effectiveness of increased monitoring of adults with HBeAg negative inactive or HBeAg positive immune tolerant CHB who have no cirrhosis or significant fibrosis and are not recommended by the current American Association for the Study of Liver Diseases (AASLD) clinical practice guidelines to receive antiviral treatment, and to assess whether the addition of HCC surveillance would be cost-effective. For every 100,000 adults with CHB who were initially not recommended for treatment, if the monitoring rate increased from the current 37% to 90% and treatment rate increased from 59% to 80%, 4,600 cases of cirrhosis, 2,450 cases of HCC and 4,700 HBV-related deaths would be averted with a gain of 45,000 QALYs and a savings of $180 million in lifetime health care costs. At a willingness to pay threshold of $100,000/QALY, the addition of HCC surveillance with the standard recommended biannual liver ultrasound and alfa fetoprotein levels is likely cost-effective if the HCC risk ≥ 0.55%/year. Regular monitoring of persons with inactive or immune tolerant CHB who are initially not recommended to receive antiviral treatment in the United States is cost-saving. The addition of HCC surveillance with biannual US and AFP would be cost-effective for individuals with HCC incidence ≥ 0.55%/year.

  View details for DOI 10.1371/journal.pone.0313898

  View details for PubMedID 39841655

  View details for PubMedCentralID PMC11753660

• Feasibility and Acceptability of Universal Adult Screening for Chronic Hepatitis B in Primary Care Clinics. AJPM focus Chu, R. V., Sarnala, S., Doan, T. V., Jamal, A., Phadke, A., So, S., So, R., Pham, H., Chaudhary, J., Huang, R., Kim, G., Palaniappan, L., Kim, K., Srinivasan, M. 2024; 3 (6): 100240

  Abstract

  Two thirds of Americans infected with chronic hepatitis B are unaware of their infection. In March 2023, the Centers for Disease Control and Prevention recommended moving from risk-based to universal adult chronic hepatitis B screening. In April 2022, Stanford implemented chronic hepatitis B universal screening discussion alerts for primary care providers.After 6 months, the authors surveyed 143 primary care providers at 13 Stanford primary care clinics about universal chronic hepatitis B screening acceptability and implementation feasibility. They conducted semistructured interviews with 15 primary care providers and 5 medical assistants around alerts and chronic hepatitis B universal versus risk-based screening.Forty-five percent of surveyed primary care providers responded. A total of 63% reported that universal screening would identify more patients with chronic hepatitis B. Before implementation, 77% ordered 0-5 chronic hepatitis B screenings per month. After implementation, 71% ordered >6 screenings per month. A total of 66% shared that universal screening removed the stigma around discussing high-risk behaviors. Interview themes included (1) low clinical burden, (2) current underscreening of at-risk groups, (3) providers preferring universal screening, (4) patients accepting universal screening, and (5) ease of chronic hepatitis B alert implementation.Consistent with Centers for Disease Control and Prevention guidelines, implementing universal chronic hepatitis B screening in primary care clinics in Northern California was feasible, was acceptable to providers and patients, eased health maintenance burdens, and improved clinic workflows.

  View details for DOI 10.1016/j.focus.2024.100240

  View details for PubMedID 39582739

  View details for PubMedCentralID PMC11584556

• Epidemiology of Chronic Hepatitis B Virus Infection, Alameda County, California, 2017-2021. Journal of public health management and practice : JPHMP Yette, E., Marusinec, R., Conlon, C., Pham, T. T., Toy, M., So, S., Wong, R. J., Chitnis, A. S. 2024

  Abstract

  In the United States, chronic hepatitis B (CHB) virus infection predominantly affects ethnic minorities and vulnerable populations.We analyzed surveillance data to describe CHB epidemiology to guide hepatitis B virus (HBV) elimination efforts in Alameda County.Persons with CHB during 2017-2021 were identified by ≥2 positive HBV tests (ie, HBsAg, HbeAg, and HBV DNA) ≥180 days apart using data from California Reportable Disease Information Exchange. Persons with CHB were stratified by age, race/ethnicity, zip code-based Healthy Places Index (HPI), and federally designated Medically Underserved Areas (MUA). Comparisons of reported CHB prevalence between groups utilized z test; comparisons between MUA regions utilized chi-square testing.A total of 8122 persons with CHB were identified; reported 5-year CHB prevalence was 0.53% (95% confidence interval: 0.52%-0.54%). Reported CHB 5-year prevalence was significantly higher among persons aged 50 to 69 years old than persons aged 30 to 49 years old (0.99%, 0.78%; P < .001) and Asians, Native Hawaiian/Pacific Islanders, African Americans compared to Whites (1.22%, 0.56%, 0.18%, 0.06%; P < .001). Reported CHB 5-year prevalence in the 2 lowest and most disadvantaged HPI quartiles was significantly higher than the 2 highest quartiles (0.55%, 0.68%, 0.37%, 0.42%; P < .001). The 1918 persons with CHB in MUA, compared to 5859 non-MUA persons, were significantly more likely to be African American (7%, 3%; P < .001) and from the lowest HPI quartile (79%, 19%; P < .001).Reported CHB 5-year prevalence in Alameda County was 1.5 times the national prevalence estimates, and reported prevalence was highest among Asians and persons in more disadvantaged areas. Analysis of local CHB surveillance data can guide public health efforts toward HBV elimination.

  View details for DOI 10.1097/PHH.0000000000002011

  View details for PubMedID 39264250

• Modelling the potential impact of global hepatitis B vaccination on the burden of chronic hepatitis B in the United States. Journal of viral hepatitis Hutton, D. W., Toy, M., Yang, D., Zhang, H., Handanagic, S., Armstrong, P. A., Wasley, A., Menzies, N. A., Pham, H., Salomon, J. A., So, S. K. 2024

  Abstract

  About 80% of persons with chronic hepatitis B virus (HBV) infection in the United States are non-US-born. Despite improvements in infant hepatitis B vaccination globally since 2000, work remains to attain the World Health Organization's (WHO) global 2030 goal of 90% vaccination. We explore the impacts on the United States of global progress in hepatitis B vaccination since 2000 and of achieving WHO hepatitis B vaccination goals. We simulated immigrants with HBV infection arriving to the United States from 2000 to 2070 using models of the 10 countries from which the largest numbers of individuals with HBV infection were born. We estimated costs in the United States among these cohorts using a disease simulation model. We simulated three scenarios: a scenario with no progress in infant vaccination for hepatitis B since 2000 (baseline), current (2020) progress and achieving WHO 2030 goals for hepatitis B vaccination. We estimate current hepatitis B vaccination progress since the 2000 baseline in these 10 countries will lead to 468,686 fewer HBV infections, avoid 35,582 hepatitis B-related deaths and save $4.2billion in the United States through 2070. Achieving the WHO 2030 90% hepatitis B infant vaccination targets could lead to an additional 16,762 fewer HBV infections, 989 fewer hepatitis B-related deaths and save $143million through 2070. Global hepatitis B vaccination since 2000 reduced prevalence of HBV infection in the United States. Achieving the WHO 2030 infant vaccination goals globally could lead to over one hundred million dollars in additional savings.

  View details for DOI 10.1111/jvh.13982

  View details for PubMedID 39037155

• EVALUATING THE IMPACT OF A UNIVERSAL ADULT ELECTRONIC HEALTH RECORD (EHR) REMINDER ON HEPATITIS B TESTING RATES: A 12-MONTH INTERVENTION STUDY Pham, H., Chang, M., Tran, D., Phadke, A., Shah, S., Srinivasan, M. SPRINGER. 2024: S910

  View details for Web of Science ID 001433572702445

• Gaps and Disparities in Chronic Hepatitis B Monitoring and Treatment in the United States, 2016-2019. Medical care Pham, T. T., Toy, M., Hutton, D., Thompson, W., Conners, E. E., Nelson, N. P., Salomon, J. A., So, S. 2023; 61 (4): 247-253

  Abstract

  BACKGROUND: Chronic hepatitis B (CHB) carries an increased risk of death from cirrhosis and hepatocellular carcinoma (HCC). The American Association for the Study of Liver Diseases recommends patients with CHB receive monitoring of disease activity, including ALT, hepatitis B virus (HBV) DNA, hepatitis B e-antigen (HBeAg), and liver imaging for patients who experience an increased risk for HCC. HBV antiviral therapy is recommended for patients with active hepatitis and cirrhosis.METHODS: Monitoring and treatment of adults with new CHB diagnoses were analyzed using Optum Clinformatics Data Mart Database claims data from January 1, 2016, to December 31, 2019.RESULTS: Among 5978 patients with new CHB diagnosis, only 56% with cirrhosis and 50% without cirrhosis had claims for≥1 ALT and either HBV DNA or HBeAg test, and among patients recommended for HCC surveillance, 82% with cirrhosis and 57% without cirrhosis had claims for≥1 liver imaging within 12 months of diagnosis. Although antiviral treatment is recommended for patients with cirrhosis, only 29% of patients with cirrhosis had≥1 claim for HBV antiviral therapy within 12 months of CHB diagnosis. Multivariable analysis showed patients who were male, Asian, privately insured, or had cirrhosis were more likely (P<0.05) to receive ALT and either HBV DNA or HBeAg tests and HBV antiviral therapy within 12 months of diagnosis.CONCLUSION: Many patients diagnosed with CHB are not receiving the clinical assessment and treatment recommended. A comprehensive initiative is needed to address the patient, provider, and system-related barriers to improve the clinical management of CHB.

  View details for DOI 10.1097/MLR.0000000000001825

  View details for PubMedID 36893410

• Gaps in Prenatal Hepatitis B Screening and Management of HBsAg Positive Pregnant Persons in the U.S., 2015-2020. American journal of preventive medicine Pham, T. T., Maria, N., Cheng, V., Nguyen, B., Toy, M., Hutton, D., Conners, E. E., Nelson, N. P., Salomon, J. A., So, S. 2023

  Abstract

  The Advisory Committee for Immunization Practices (ACIP) recommends testing all pregnant women for hepatitis B surface antigen (HBsAg) and testing HBsAg-positive pregnant women for hepatitis B virus deoxyribonucleic acid (HBV DNA). HBsAg-positive pregnant persons are recommended by the American Association for the Study of Liver Diseases to receive regular monitoring, including alanine transaminase (ALT) and HBV DNA and antiviral therapy for active hepatitis and to prevent perinatal HBV transmission if HBV DNA level is >200,000 IU/mL.Using Optum Clinformatics Data Mart Database claims data, pregnant women who received HBsAg testing and HBsAg-positive pregnant persons who received HBV DNA and alt testing and antiviral therapy during pregnancy and after delivery during January 1, 2015-December 31, 2020 were analyzed.Among 506,794 pregnancies, 14.6% did not receive HBsAg testing. Pregnant women more likely to receive testing for HBsAg (p<0.01) were persons aged ≥20 years, were Asian, had >1 child, or received education beyond high school. Among the 0.28% (1,437) pregnant women who tested positive for hepatitis B surface antigen, 46% were Asian. The proportion of HBsAg-positive pregnant women who received HBV DNA testing during pregnancy and in the 12 months after delivery was 44.3% and 28.6%, respectively; the proportion that received HBsAg was 31.6% and 12.7%, respectively; the proportion that received ALT testing was 67.4% and 47%, respectively; and the proportion that received HBV antiviral therapy was 7% and 6.2%, respectively.This study suggests that as many as half a million (∼14%) pregnant persons who gave birth each year were not tested for HBsAg to prevent perinatal transmission. More than 50% of HBsAg-positive persons did not receive the recommended HBV-directed monitoring tests during pregnancy and after delivery.

  View details for DOI 10.1016/j.amepre.2023.01.041

  View details for PubMedID 36906494

• Knowledge and Attitude Related to Hepatitis C among Medical Students in the Oral Direct Acting Antiviral Agents Era in Vietnam. International journal of environmental research and public health Pham, T. T., Nguyen, T. T., So, S., Hoang, T. H., Nguyen, T. T., Ngo, T. B., Nguyen, M. P., Thai, Q. H., Nguyen, N. K., Ho, T. Q., Tran, Q. P., Mai, T. S., Toy, M., Pham, M. K. 2022; 19 (19)

  Abstract

  BACKGROUND: Medical students play important frontline roles in the prevention, early detection, and treatment of hepatitis C. This study investigated knowledge and attitudes toward hepatitis C among 5th- and 6th-year medical students and possible associated factors.METHODS: A cross-sectional survey was conducted among 2000 students from eight medical universities using a self-administered structured questionnaire.RESULTS: The mean knowledge and attitude scores for hepatitis C were 20.1 ± 4.0 (out of 26) and 10.6 ± 2.9 (out of 20), respectively. Approximately, three-quarters (74.4%) of the participants had a good knowledge score, but only a small proportion (3.1%) obtained a good attitude score. Although the participants had fairly high knowledge about the causes, consequences, and transmission routes of hepatitis C, there were important gaps in their knowledge about hepatitis C screening and treatment. In multivariate analysis, female students, 5th-year students, and students from the central provinces had significantly higher knowledge and attitude scores. There was a low positive correlation between knowledge and attitude scores.CONCLUSION: This study points out the need to update the medical training curriculum to improve the knowledge and attitude of students about hepatitis C infection.

  View details for DOI 10.3390/ijerph191912298

  View details for PubMedID 36231600

• Causes and trends in liver disease and hepatocellular carcinoma among men and women who received liver transplants in the U.S., 2010-2019. PloS one Wang, S. n., Toy, M. n., Hang Pham, T. T., So, S. n. 2020; 15 (9): e0239393

  Abstract

  The national Organ Procurement and Transplant Network (OPTN) reported the major indication for liver transplants in 2018 was for other/unknown causes. This study was undertaken to examine all causes and trends in liver disease and hepatocellular carcinoma (HCC) among adults who received liver transplants in the past 10 years.A national cohort study of all adults who received liver transplants from Jan 1, 2010 to Dec 31, 2019 recorded in the OPTN STAR database analyzed by etiology of liver disease and HCC, and gender.Adult liver transplants increased from 5,731 in 2010 to 8,345 in 2019 (45.6% increase). Between 2010 and 2014, liver disease and HCC associated with hepatitis C (HCV) was the major cause for liver transplantation. Proportion of liver transplants for HCV associated liver disease and HCC has since decreased to 18.7% in 2019 compared with 44.5% in 2010 [25.8%, (95% CI 24.3% to 27.3%), p<0.001], while liver transplants for liver disease and HCC associated with alcohol-associated liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) increased from 12.7% to 28.8% [16.1%, (95% CI 14.8% to 17.4%), p<0.001], and from 9.1% to 21.5% [12.4%, (95% CI 11.2% to 13.5%), p<0.001], respectively. When all causes of liver disease were examined, only 1.7% of liver transplants had unspecified causes. The five major causes of liver disease and HCC among men receiving liver transplants in 2019 were ALD (33.1%), HCV (21.9%), NAFLD (18.5%), cholestatic liver disease (5.7%) and hepatitis B (4.9%), while the major causes among women were NAFLD (26.8%), ALD (21.1%), HCV (13.1%), cholestatic liver disease (11.1%), and autoimmune liver disease (5.6%).Our study found NAFLD in 2017 in women and ALD in 2019 in men have surpassed HCV as the leading causes of liver disease and HCC among adults receiving liver transplants.

  View details for DOI 10.1371/journal.pone.0239393

  View details for PubMedID 32946502

• Knowledge, attitudes and practices of hepatitis B prevention and immunization of pregnant women and mothers in northern Vietnam. PloS one Hang Pham, T. T., Le, T. X., Nguyen, D. T., Luu, C. M., Truong, B. D., Tran, P. D., Toy, M., So, S. 2019; 14 (4): e0208154

  Abstract

  BACKGROUND AND AIM: Infection at birth due to mother-to-child (MTC) transmission is the most common cause of chronic hepatitis B virus (HBV) infection in Vietnam. This study was undertaken to examine the knowledge, attitudes, and practices of pregnant women and mothers in Vietnam concerning HBV prevention and immunization.METHODS: A cross-sectional survey was conducted in Quang Ninh and Hoa Binh provinces in 2017. A standardized questionnaire was administered to women when they received care at primary and tertiary maternal health clinics. Multivariate regression was used to identify predictors of HBV knowledge and practices.RESULTS: Among the 380 women surveyed, 50.3% were pregnant and 49.7% were postpartum. Despite 70.3% of participants reported having received information about HBV during their pregnancy, only 10.8% provided correct answers to all questions regarding HBV transmission routes and preventive measures. Around half of the participants incorrectly believed that HBV is transmitted through sneezing, contaminated water or sharing foods with chronic HBV patients. Although 86.1% of participants believed that HBV vaccination is necessary for infants, only 66.1% responded they were definitely willing to have their own child vaccinated within 24 hours. More than a third of participants expressed concern about having casual contacts or sharing foods with chronic HBV patients. In multivariate analysis, having received information about HBV during their pregnancy was significantly associated with better HBV knowledge score. Delivery at provincial level clinics was a strong predictor for perinatal HBV screening and hepatitis B birth dose administration.CONCLUSIONS: The results highlight the need to prioritize educating pregnant women and mothers in future public health campaigns in order to increase knowledge, reduce misperception, and improve hepatitis B vaccine birth dose coverage in Vietnam.

  View details for PubMedID 30969972

• Knowledge, attitudes and medical practice regarding hepatitis B prevention and management among healthcare workers in Northern Vietnam. PloS one Hang Pham, T. T., Le, T. X., Nguyen, D. T., Luu, C. M., Truong, B. D., Tran, P. D., Toy, M., Bozkurt, S., So, S. 2019; 14 (10): e0223733

  Abstract

  BACKGROUND AND AIM: Vietnam's burden of liver cancer is largely due to its high prevalence of chronic hepatitis B virus (HBV) infection. This study aimed to examine healthcare workers' (HCWs) knowledge, attitude and practices regarding HBV prevention and management.METHODS: A cross-sectional survey among health care workers working at primary and tertiary facilities in two Northern provinces in Vietnam in 2017. A standardized questionnaire was administered to randomly selected HCWs. Multivariate regression was used to identify predictors of the HBV knowledge score.RESULTS: Among the 314 participants, 75.5% did not know HBV infection at birth carries the highest risk of developing chronic infection. The median knowledge score was 25 out of 42 (59.5%). About one third (30.2%) wrongly believed that HBV can be transmitted through eating or sharing food with chronic hepatitis B patients. About 38.8% did not feel confident that the hepatitis B vaccine is safe. Only 30.1% provided correct answers to all the questions on injection safety. Up to 48.2% reported they consistently recap needles with two hands after injection, a practice that would put them at greater risk of needle stick injury. About 24.2% reported having been pricked by a needle at work within the past 12 months. More than 40% were concerned about having casual contact or sharing food with a person with chronic hepatitis B infection (CHB). In multivariate analysis, physicians scored significantly higher compared to other healthcare professionals. Having received training regarding hepatitis B within the last two years was also significantly associated with a better HBV knowledge score.CONCLUSIONS: Findings from the survey indicated an immediate need to implement an effective hepatitis B education and training program to build capacity among Vietnam's healthcare workers in hepatitis B prevention and control and to dispel hepatitis B stigma.

  View details for DOI 10.1371/journal.pone.0223733

  View details for PubMedID 31609983