An Interactive Modeling Tool for Projecting the Health and Direct Medical Cost Impact of Changes in the Sexually Transmitted Diseases Prevention Program Budgets

CONTEXT

Estimating the return on investment for public health services, tailored to the state level, is critical for demonstrating their value and making resource allocation decisions. However, many health departments have limited staff capacity and expertise to conduct economic analyses in-house.

PROGRAM

We developed a user-friendly, interactive Excel-based spreadsheet model that health departments can use to estimate the impact of increases or decreases in sexually transmitted infection (STI) prevention funding on the incidence and direct medical costs of chlamydia, gonorrhea, syphilis, and STI-attributable HIV infections. Users tailor results to their jurisdictions by entering the size of their population served; the number of annual STI diagnoses; their prior annual funding amount; and their anticipated new funding amount. The interface was developed using human-centered design principles, including focus groups with 15 model users to collect feedback on an earlier model version and a usability study on the prototype with 6 model users to finalize the interface.

IMPLEMENTATION

The STI Prevention Allocation Consequences Estimator ("SPACE Monkey 2.0") model will be publicly available as a free downloadable tool.

EVALUATION

In the usability testing of the prototype, participants provided overall positive feedback. They appreciated the clear interpretations, outcomes expressed as direct medical costs, functionalities to interact with the output and copy charts into external applications, visualization designs, and accessible information about the model's assumptions and limitations. Participants provided positive responses to a 10-item usability evaluation survey regarding their experiences with the prototype.

DISCUSSION

Modeling tools that synthesize literature-based estimates and are developed with human-centered design principles have the potential to make evidence-based estimates of budget changes widely accessible to health departments.

Building a Simple Model to Assess the Impact of Case Investigation and Contact Tracing for Sexually Transmitted Diseases: Lessons From COVID-19

Introduction

During the COVID-19 pandemic, the U.S. Centers for Disease Control and Prevention developed a simple spreadsheet-based tool to help state and local public health officials assess the performance and impact of COVID-19 case investigation and contact tracing in their jurisdiction. The applicability and feasibility of building such a tool for sexually transmitted diseases were assessed.

Methods

The key epidemiologic differences between sexually transmitted diseases and respiratory diseases (e.g., mixing patterns, incubation period, duration of infection, and the availability of treatment) were identified, and their implications for modeling case investigation and contact tracing impact with a simple spreadsheet tool were remarked on. Existing features of the COVID-19 tool that are applicable for evaluating the impact of case investigation and contact tracing for sexually transmitted diseases were also identified.

Results

Our findings offer recommendations for the future development of a spreadsheet-based modeling tool for evaluating the impact of sexually transmitted disease case investigation and contact tracing efforts. Generally, we advocate for simplifying sexually transmitted disease-specific complexities and performing sensitivity analyses to assess uncertainty. The authors also acknowledge that more complex modeling approaches might be required but note that it is possible that a sexually transmitted disease case investigation and contact tracing tool could incorporate features from more complex models while maintaining a user-friendly interface.

Conclusions

A sexually transmitted disease case investigation and contact tracing tool could benefit from the incorporation of key features of the COVID-19 model, namely its user-friendly interface. The inherent differences between sexually transmitted diseases and respiratory viruses should not be seen as a limitation to the development of such tool.

Analyzing the Costs and Impact of the TakeMeHome Program, a Public-Private Partnership to Deliver HIV Self-Test Kits in the United States

BACKGROUND

HIV testing is an entry point to access HIV care and prevention services. Building Healthy Online Communities developed a website ( TakeMeHome.org ) where participants can order HIV home test kits. The purpose of this study was to analyze the costs and impact of the TakeMeHome program.

METHODS

We estimated the costs of TakeMeHome across all participating jurisdictions for the first year of the program. We estimated program costs using purchase orders and invoices, contracts, and allocation of staff time, and the costs included website design, participant recruitment, administration and overhead, HIV self-test kits, and shipping and handling. Primary outcomes of the analysis were total program cost, cost per HIV test, and cost per new HIV diagnosis.

RESULTS

The TakeMeHome program distributed 5323 HIV self-tests to 4859 participants over a 12-month period. The total program cost over this period was $314,870. The cost per HIV test delivered was estimated at $59, and the cost per person tested was $65. The program identified 18 confirmed new HIV diagnoses (0.6% positivity) verified with surveillance data in 7 health jurisdictions at $169,890. The cost per confirmed new HIV diagnosis was estimated at $9440.

CONCLUSIONS

The TakeMeHome program delivered HIV self-testing at a reasonable cost, and the program may be a cost-effective use of HIV prevention resources. The public-private partnership can be an effective mechanism to validate HIV diagnoses identified with self-testing and provide HIV prevention and linkage to care services.

Costs, Health Benefits, and Cost-Effectiveness of Chlamydia Screening and Partner Notification in the United States, 2000-2019: A Mathematical Modeling Analysis

BACKGROUND

Chlamydia remains a significant public health problem that contributes to adverse reproductive health outcomes. In the United States, sexually active women 24 years and younger are recommended to receive annual screening for chlamydia. In this study, we evaluated the impact of estimated current levels of screening and partner notification (PN), and the impact of screening based on guidelines on chlamydia associated sequelae, quality adjusted life years (QALYs) lost and costs.

METHODS

We conducted a cost-effectiveness analysis of chlamydia screening, using a published calibrated pair formation transmission model that estimated trends in chlamydia screening coverage in the United States from 2000 to 2015 consistent with epidemiological data. We used probability trees to translate chlamydial infection outcomes into estimated numbers of chlamydia-associated sequelae, QALYs lost, and health care services costs (in 2020 US dollars). We evaluated the costs and population health benefits of screening and PN in the United States for 2000 to 2015, as compared with no screening and no PN. We also estimated the additional benefits that could be achieved by increasing screening coverage to the levels indicated by the policy recommendations for 2016 to 2019, compared with screening coverage achieved by 2015.

RESULTS

Screening and PN from 2000 to 2015 were estimated to have averted 1.3 million (95% uncertainty interval [UI] 490,000-2.3 million) cases of pelvic inflammatory disease, 430,000 (95% UI, 160,000-760,000) cases of chronic pelvic pain, 300,000 (95% UI, 104,000-570,000) cases of tubal factor infertility, and 140,000 (95% UI, 47,000-260,000) cases of ectopic pregnancy in women. We estimated that chlamydia screening and PN cost $9700 per QALY gained compared with no screening and no PN. We estimated the full realization of chlamydia screening guidelines for 2016 to 2019 to cost $30,000 per QALY gained, compared with a scenario in which chlamydia screening coverage was maintained at 2015 levels.

DISCUSSION

Chlamydia screening and PN as implemented in the United States from 2000 through 2015 has substantially improved population health and provided good value for money when considering associated health care services costs. Further population health gains are attainable by increasing screening further, at reasonable cost per QALY gained.

Updated estimate of the annual direct medical cost of screening and treatment for human papillomavirus associated disease in the United States

The annual direct medical cost attributable to human papillomavirus (HPV) in the United States over the period 2004-2007 was estimated at $9.36 billion in 2012 (updated to 2020 dollars). The purpose of this report was to update that estimate to account for the impact of HPV vaccination on HPV-attributable disease, reductions in the frequency of cervical cancer screening, and new data on the cost per case of treating HPV-attributable cancers. Based primarily on data from the literature, we estimated the annual direct medical cost burden as the sum of the costs of cervical cancer screening and follow-up and the cost of treating HPV-attributable cancers, anogenital warts, and recurrent respiratory papillomatosis (RRP). We estimated the total direct medical cost of HPV to be $9.01 billion annually over the period 2014-2018 (2020 U.S. dollars). Of this total cost, 55.0% was for routine cervical cancer screening and follow-up, 43.8% was for treatment of HPV-attributable cancer, and less than 2% was for treating anogenital warts and RRP. Although our updated estimate of the direct medical cost of HPV is slightly lower than the previous estimate, it would have been substantially lower had we not incorporated more recent, higher cancer treatment costs.

Lifetime quality-adjusted life years lost due to genital herpes acquired in the United States in 2018: a mathematical modeling study

Background

Genital herpes (GH), caused by herpes simplex virus type 1 and type 2 (HSV-1, HSV-2), is a common sexually transmitted disease associated with adverse health outcomes. Symptoms associated with GH outbreaks can be reduced by antiviral medications, but the infection is incurable and lifelong. In this study, we estimate the long-term health impacts of GH in the United States using quality-adjusted life years (QALYs) lost.

Methods

We used probability trees to model the natural history of GH secondary to infection with HSV-1 and HSV-2 among people aged 18-49 years. We modelled the following outcomes to quantify the major causes of health losses following infection: symptomatic herpes outbreaks, psychosocial impacts associated with diagnosis and recurrences, urinary retention caused by sacral radiculitis, aseptic meningitis, Mollaret's meningitis, and neonatal herpes. The model was parameterized based on published literature on the natural history of GH. We summarized losses of health by computing the lifetime number of QALYs lost per genital HSV-1 and HSV-2 infection, and we combined this information with incidence estimates to compute the total lifetime number of QALYs lost due to infections acquired in 2018 in the United States.

Findings

We estimated 0.05 (95% uncertainty interval (UI) 0.02-0.08) lifetime QALYs lost per incident GH infection acquired in 2018, equivalent to losing 0.05 years or about 18 days of life for one person with perfect health. The average number of QALYs lost per GH infection due to genital HSV-1 and HSV-2 was 0.01 (95% UI 0.01-0.02) and 0.05 (95% UI 0.02-0.09), respectively. The burden of genital HSV-1 is higher among women, while the burden of HSV-2 is higher among men. QALYs lost per neonatal herpes infection was estimated to be 7.93 (95% UI 6.63-9.19). At the population level, the total estimated lifetime QALYs lost as a result of GH infections acquired in 2018 was 33,100 (95% UI 12,600-67,900) due to GH in adults and 3,140 (95% UI 2,260-4,140) due to neonatal herpes. Results were most sensitive to assumptions on the magnitude of the disutility associated with post-diagnosis psychosocial distress and symptomatic recurrences.

Interpretation

GH is associated with substantial health losses in the United States. Results from this study can be used to compare the burden of GH to other diseases, and it provides inputs that may be used in studies on the health impact and cost-effectiveness of interventions that aim to reduce the burden of GH.

Funding

The Center for Disease Control and Prevention.

The estimated lifetime quality-adjusted life-years lost due to chlamydia, gonorrhea, and trichomoniasis in the United States in 2018

OBJECTIVES

We quantified the quality-adjusted life-years (QALYs) lost attributable to chlamydia, gonorrhea, and trichomoniasis in the US, by sex and age group.

METHODS

We adapted a previous probability-tree model to estimate the average number of lifetime QALYs lost due to genital chlamydia, gonorrhea, and trichomoniasis, per incident infection and at the population level, by sex and age group. We conducted multivariate sensitivity analyses to address uncertainty around key parameter values.

FINDINGS

The estimated total discounted lifetime QALYs lost for men and women, respectively, due to infections acquired in 2018, were 1,541 (95% uncertainty interval: 186, 6,358) and 111,872 (29,777, 267,404) for chlamydia, 989 (127, 3,720) and 12,112 (2,410, 33,895) for gonorrhea, and 386 (30, 1,851) and 4,576 (13, 30,355) for trichomoniasis. Total QALYs lost were highest among women ages 15-24 years with chlamydia. QALYs lost estimates were highly sensitive to disutilities (health losses) of infections and sequelae, and to duration of infections and chronic sequelae for chlamydia and gonorrhea in women.

CONCLUSIONS

The three sexually transmitted infections cause substantial health losses in the US, particularly gonorrhea and chlamydia among women. The estimates of lifetime QALYs lost per infection help to prioritize prevention policies and inform cost-effectiveness analyses of STI interventions.

Health Economics Research in Primary Prevention of Cancer: Assessment, Current Challenges, and Future Directions

In the past 2 decades, the demand for information on health economics research to guide health care decision making has substantially increased. Studies have provided evidence that eliminating or reducing tobacco use; eating a healthy diet, including fruit and vegetables; being physically active; reducing alcohol consumption; avoiding ultraviolet radiation; and minimizing exposure to environmental and occupational carcinogenic agents should substantially reduce cancer incidence in the population. The benefits of these primary prevention measures in reducing cancer incidence are not instantaneous. Therefore, health economics research has an important role to play in providing credible information to decision makers on the health and economic benefits of primary prevention. This article provides an overview of health economics research related to primary prevention of cancer. We addressed the following questions: 1) What are the gaps and unmet needs for performing health economics research focused on primary prevention of cancer? 2) What are the challenges and opportunities to conducting health economics research to evaluate primary prevention of cancer? and 3) What are the future directions for enhancing health economics research on primary prevention of cancer? Modeling primary prevention of cancer is often difficult given data limitations, long delays before the policy or intervention is effective, possible unintended effects of the policy or intervention, and the necessity of outside expertise to understand key inputs or outputs to the modeling. Despite these challenges, health economics research has an important role to play in providing credible information to decision makers on the health and economic benefits of primary prevention of cancer.

Variation in Patterns of Racial and Ethnic Disparities in Primary and Secondary Syphilis Diagnosis Rates Among Heterosexually Active Women by Region and Age Group in the United States

BACKGROUND

Syphilis rates have increased substantially over the past decade. Women are an important population because of negative sequalae and adverse maternal outcomes including congenital syphilis. We assessed whether racial and ethnic disparities in primary and secondary (P&S) syphilis among heterosexually active women differ by region and age group.

METHODS

We synthesized 4 national surveys to estimate numbers of heterosexually active women in the United States from 2014 to 2018 by region, race and ethnicity, and age group (18-24, 25-29, 30-44, and ≥45 years). We calculated annual P&S syphilis diagnosis rates, assessing disparities with rate differences and rate ratios comparing White, Hispanic, and Black heterosexually active women.

RESULTS

Nationally, annual rates were 6.42 and 2.20 times as high among Black and Hispanic than among White heterosexually active women (10.99, 3.77, and 1.71 per 100,000, respectively). Younger women experienced a disproportionate burden of P&S syphilis and the highest disparities. Regionally, the Northeast had the highest Black-White and Hispanic-White disparities using a relative disparity measure (relative rate), and the West had the highest disparities using an absolute disparity measure (rate difference).

CONCLUSIONS

To meet the racial and ethnic disparity goals of the Sexually Transmitted Infections National Strategic Plan, tailored local interventions that address the social and structural factors associated with disparities are needed for different age groups.

Modeling the Cost-Effectiveness of Express Multisite Gonorrhea Screening Among Men Who Have Sex With Men in the United States

BACKGROUND

Men who have sex with men (MSM) experience high rates of gonococcal infection at extragenital (rectal and pharyngeal) anatomic sites, which often are missed without asymptomatic screening and may be important for onward transmission. Implementing an express pathway for asymptomatic MSM seeking routine screening at their clinic may be a cost-effective way to improve extragenital screening by allowing patients to be screened at more anatomic sites through a streamlined, less costly process.

METHODS

We modified an agent-based model of anatomic site-specific gonococcal infection in US MSM to assess the cost-effectiveness of an express screening pathway in which all asymptomatic MSM presenting at their clinic were screened at the urogenital, rectal, and pharyngeal sites but forewent a provider consultation and physical examination and self-collected their own samples. We calculated the cumulative health effects expressed as gonococcal infections and cases averted over 5 years, labor and material costs, and incremental cost-effectiveness ratios for express versus traditional scenarios.

RESULTS

The express scenario averted more infections and cases in each intervention year. The increased diagnostic costs of triple-site screening were largely offset by the lowered visit costs of the express pathway and, from the end of year 3 onward, this pathway generated small cost savings. However, in a sensitivity analysis of assumed overhead costs, cost savings under the express scenario disappeared in the majority of simulations once overhead costs exceeded 7% of total annual costs.

CONCLUSIONS

Express screening may be a cost-effective option for improving multisite anatomic screening among US MSM.

The Estimated Lifetime Medical Cost of Syphilis in the United States

BACKGROUND

The purpose of this study was to estimate the cost of syphilis in the United States, in terms of the average lifetime direct medical cost per infection.

METHODS

We used a decision tree model of the natural history of syphilis. The model allowed for numerous possible outcomes of infection, including treatment for syphilis at various stages, inadvertent treatment, and late syphilis outcomes in those who are alive and still infected 30 years after acquisition. Future costs were discounted at 3% annually. Model inputs, such as the cost and probability of each outcome, were based on published sources. The probabilities we applied yielded outcomes consistent with reported cases of syphilis by stage from national surveillance data and number of deaths due to late syphilis from national mortality data.

RESULTS

The estimated, discounted lifetime cost per infection was $1190 under base case assumptions (2019 dollars). Treatment costs associated with late syphilis outcomes, such as cardiovascular syphilis, accounted for only $26 of the average lifetime cost per infection. Results were most sensitive to assumptions regarding the treatment cost per case of unknown duration or late syphilis. In the probabilistic sensitivity analyses, the 2.5th and 97.5th percentiles of the 10,000 simulations of the lifetime cost per infection were $729 and $1884, respectively.

CONCLUSIONS

Our estimate of the lifetime cost per infection is about 50% higher than in a previous study, a difference due in large part to our higher cost assumptions for benzathine penicillin G.

The Estimated Lifetime Medical Cost of Diseases Attributable to Human Papillomavirus Infections Acquired in 2018

INTRODUCTION

We estimated the lifetime medical costs of diagnosed cases of diseases attributable to human papillomavirus (HPV) infections acquired in 2018.

METHODS

We adapted an existing mathematical model of HPV transmission and associated diseases to estimate the lifetime number of diagnosed cases of disease (genital warts; cervical intraepithelial neoplasia; and cervical, vaginal, vulvar, penile, anal, and oropharyngeal cancers) attributable to HPV infections that were acquired in 2018. For each of these outcomes, we multiplied the estimated number of cases by the estimated lifetime medical cost per case obtained from previous studies. We estimated the costs of recurrent respiratory papillomatosis in a separate calculation. Future costs were discounted at 3% annually.

RESULTS

The estimated discounted lifetime medical cost of diseases attributable to HPV infections acquired in 2018 among people aged 15 to 59 years was $774 million (in 2019 US dollars), of which approximately half was accounted for by infections in those aged 15 to 24 years. Human papillomavirus infections in women accounted for approximately 90% of the lifetime number of diagnosed cases of disease and 70% of the lifetime cost attributable to HPV infections acquired in 2018 among those aged 15 to 59 years.

CONCLUSIONS

We estimated the lifetime medical costs of diseases attributable to HPV infections acquired in 2018 to be $774 million. This estimate is lower than previous estimates, likely due to the impact of HPV vaccination. The lifetime cost of disease attributable to incident HPV infections is expected to decrease further over time as HPV vaccination coverage increases.

The Estimated Direct Lifetime Medical Costs of Sexually Transmitted Infections Acquired in the United States in 2018

BACKGROUND

We estimated the lifetime medical costs attributable to sexually transmitted infections (STIs) acquired in 2018, including sexually acquired human immunodeficiency virus (HIV).

METHODS

We estimated the lifetime medical costs of infections acquired in 2018 in the United States for 8 STIs: chlamydia, gonorrhea, trichomoniasis, syphilis, genital herpes, human papillomavirus (HPV), hepatitis B, and HIV. We limited our analysis to lifetime medical costs incurred for treatment of STIs and for treatment of related sequelae; we did not include other costs, such as STI prevention. For each STI, except HPV, we calculated the lifetime medical cost by multiplying the estimated number of incident infections in 2018 by the estimated lifetime cost per infection. For HPV, we calculated the lifetime cost based on the projected lifetime incidence of health outcomes attributed to HPV infections acquired in 2018. Future costs were discounted at 3% annually.

RESULTS

Incident STIs in 2018 imposed an estimated $15.9 billion (25th-75th percentile: $14.9-16.9 billion) in discounted, lifetime direct medical costs (2019 US dollars). Most of this cost was due to sexually acquired HIV ($13.7 billion) and HPV ($0.8 billion). STIs in women accounted for about one fourth of the cost of incident STIs when including HIV, but about three fourths when excluding HIV. STIs among 15- to 24-year-olds accounted for $4.2 billion (26%) of the cost of incident STIs.

CONCLUSIONS

Incident STIs continue to impose a considerable lifetime medical cost burden in the United States. These results can inform health economic analyses to promote the use of cost-effective STI prevention interventions to reduce this burden.

Estimated Prevalence and Incidence of Disease-Associated Human Papillomavirus Types Among 15- to 59-Year-Olds in the United States

INTRODUCTION

Human papillomavirus (HPV) can cause anogenital warts and several types of cancer, including cervical cancers and precancers. We estimated the prevalence, incidence, and number of persons with prevalent and incident HPV infections in the United States in 2018.

METHODS

Prevalence and incidence were estimated for infections with any HPV (any of 37 types detected using Linear Array) and disease-associated HPV, 2 types that cause anogenital warts plus 14 types detected by tests used for cervical cancer screening (HPV 6/11/16/18/31/33/35/39/45/51/52/56/58/59/66/68). We used the 2013-2016 National Health and Nutrition Examination Survey to estimate prevalence among 15- to 59-year-olds, overall and by sex. Incidences in 2018 were estimated per 10,000 persons using an individual-based transmission-dynamic type-specific model calibrated to US data. We estimated number of infected persons by applying prevalences and incidences to 2018 US population estimates.

RESULTS

Prevalence of infection with any HPV was 40.0% overall, 41.8% in men, and 38.4% in women; prevalence of infection with disease-associated HPV was 24.2% in men and 19.9% in women. An estimated 23.4 and 19.2 million men and women had a disease-associated HPV type infection in 2018. Incidences of any and disease-associated HPV infection were 1222 and 672 per 10,000 persons; incidence of disease-associated HPV infection was 708 per 10,000 men and 636 per 10,000 women. An estimated 6.9 and 6.1 million men and women had an incident infection with a disease-associated HPV type in 2018.

CONCLUSIONS

We document a high HPV burden of infection in the United States in 2018, with 42 million persons infected with disease-associated HPV and 13 million persons acquiring a new infection. Although most infections clear, some disease-associated HPV type infections progress to disease. The HPV burden highlights the need for continued monitoring of HPV-associated cancers, cervical cancer screening, and HPV vaccination to track and prevent disease.

Potential for Point-of-Care Tests to Reduce Chlamydia-associated Burden in the United States: A Mathematical Modeling Analysis

Background

Point-of-care testing (POCT) assays for chlamydia are being developed. Their potential impact on the burden of chlamydial infection in the United States, in light of suboptimal screening coverage, remains unclear.

Methods

Using a transmission model calibrated to data in the United States, we estimated the impact of POCT on chlamydia prevalence, incidence, and chlamydia-attributable pelvic inflammatory disease (PID) incidence, assuming status quo (Analysis 1) and improved (Analysis 2) screening frequencies. We tested the robustness of results to changes in POCT sensitivity, the proportion of patients getting treated immediately, the baseline proportion lost to follow-up (LTFU), and the average treatment delay.

Results

In Analysis 1, high POCT sensitivity was needed to reduce the chlamydia-associated burden. With a POCT sensitivity of 90%, reductions from the baseline burden only occurred in scenarios in which over 60% of the screened individuals would get immediate treatment and the baseline LTFU proportion was 20%. With a POCT sensitivity of 99% (baseline LTFU 10%, 2-week treatment delay), if everyone were treated immediately, the prevalence reduction was estimated at 5.7% (95% credible interval [CrI] 3.9–8.2%). If only 30% of tested persons would wait for results, the prevalence reduction was only 1.6% (95% CrI 1.1–2.3). POCT with 99% sensitivity could avert up to 12 700 (95% CrI 5000–22 200) PID cases per year, if 100% were treated immediately (baseline LTFU 20% and 3-week treatment delay). In Analysis 2, when POCT was coupled with increasing screening coverage, reductions in the chlamydia burden could be realized with a POCT sensitivity of 90%.

Conclusions

POCT could improve chlamydia prevention efforts if test performance characteristics are significantly improved over currently available options.

Cost-effectiveness of HPV vaccination for adults through age 45 years in the United States: Estimates from a simplified transmission model

INTRODUCTION

The objective of this study was to assess incremental costs and benefits of a human papillomavirus (HPV) vaccination program expanded to include "mid-adults" (adults aged 27 through 45 years) in the United States.

METHODS

We adapted a previously published, dynamic mathematical model of HPV transmission and HPV-associated disease to estimate the incremental costs and benefits of a 9-valent HPV vaccine (9vHPV) program for people aged 12 through 45 years compared to a 9vHPV program for females aged 12 through 26 years and males aged 12 through 21 years.

RESULTS

A 9vHPV program for females aged 12 through 26 years and males aged 12 through 21 years was estimated to cost < $10,000 quality-adjusted life year (QALY) gained, compared to no vaccination. Expanding the 9vHPV program to include mid-adults was estimated to cost $587,600 per additional QALY gained when including adults through age 30 years, and $653,300 per additional QALY gained when including adults through age 45 years. Results were most sensitive to assumptions about HPV incidence among mid-adults, current and historical vaccination coverage, vaccine price, and the impact of HPV diseases on quality of life.

CONCLUSIONS

Mid-adult vaccination is much less cost-effective than the comparison strategy of routine vaccination for all adolescents at ages 11 to 12 years and catch-up vaccination for women through age 26 years and men through age 21 years.

Does including violent crime rates in ecological regression models of sexually transmissible infection rates improve model quality? Insights from spatial regression analyses

Background Violent crime rates are often correlated with the hard-to-measure social determinants of sexually transmissible infections (STIs). In this study, we examined whether including violent crime rate as an independent variable can improve the quality of ecological regression models of STIs.

METHODS

We obtained multiyear (2008-12) cross-sectional county-level data on violent crime and three STIs (chlamydia, gonorrhoea, and primary and secondary (P&S) syphilis) from counties in all the contiguous states in the US (except Illinois and Florida, due to lack of data). We used two measures of STI morbidity (one categorical and one continuous) and applied spatial regression with the spatial error model for each STI, with and without violent crime rate as an independent variable. We computed the associated Akaike's information criterion (AIC) and Bayesian information criterion (BIC) as our measure of the relative goodness of fit of the models.

RESULTS

Including the violent crime rate as an independent variable improved the quality of the regression models after controlling for several sociodemographic factors. We found that the lower calculated AICs and BICs indicated more favourable goodness of fit in all the models that included violent crime rates, except for the categorical P&S syphilis model, in which the violent crime variable was not statistically significant.

CONCLUSION

Because violent crime rates can account for the hard-to-measure social determinants of STIs, including violent crime rate as an independent variable can improve ecological regression models of STIs.

Effectiveness and Cost-Effectiveness of Human Papillomavirus Vaccination Through Age 45 Years in the United States

BACKGROUND

In the United States, the routine age for human papillomavirus (HPV) vaccination is 11 to 12 years, with catch-up vaccination through age 26 years for women and 21 years for men. U.S. vaccination policy on use of the 9-valent HPV vaccine in adult women and men is being reviewed.

OBJECTIVE

To evaluate the added population-level effectiveness and cost-effectiveness of extending the current U.S. HPV vaccination program to women aged 27 to 45 years and men aged 22 to 45 years.

DESIGN

The analysis used HPV-ADVISE (Agent-based Dynamic model for VaccInation and Screening Evaluation), an individual-based transmission dynamic model of HPV infection and associated diseases, calibrated to age-specific U.S. data.

DATA SOURCES

Published data.

TARGET POPULATION

Women aged 27 to 45 years and men aged 22 to 45 years in the United States.

TIME HORIZON

100 years.

PERSPECTIVE

Health care sector.

INTERVENTION

9-valent HPV vaccination.

OUTCOME MEASURES

HPV-associated outcomes prevented and cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

The model predicts that the current U.S. HPV vaccination program will reduce the number of diagnoses of anogenital warts and cervical intraepithelial neoplasia of grade 2 or 3 and cases of cervical cancer and noncervical HPV-associated cancer by 82%, 80%, 59%, and 39%, respectively, over 100 years and is cost saving (vs. no vaccination). In contrast, extending vaccination to women and men aged 45 years is predicted to reduce these outcomes by an additional 0.4, 0.4, 0.2, and 0.2 percentage points, respectively. Vaccinating women and men up to age 30, 40, and 45 years is predicted to cost $830 000, $1 843 000, and $1 471 000, respectively, per quality-adjusted life-year gained (vs. current vaccination).

RESULTS OF SENSITIVITY ANALYSIS

Results were most sensitive to assumptions about natural immunity and progression rates after infection, historical vaccination coverage, and vaccine efficacy.

LIMITATION

Uncertainty about the proportion of HPV-associated disease due to infections after age 26 years and about the level of herd effects from the current HPV vaccination program.

CONCLUSION

The current HPV vaccination program is predicted to be cost saving. Extending vaccination to older ages is predicted to produce small additional health benefits and result in substantially higher incremental cost-effectiveness ratios than the current recommendation.

PRIMARY FUNDING SOURCE

Centers for Disease Control and Prevention.

Estimated Impact of Screening on Gonorrhea Epidemiology in the United States: Insights From a Mathematical Model

The burden of gonorrhea infections in the United States is high. There are marked disparities by race/ethnicity and sexual orientation. We quantified the impact of screening and treatment on gonorrhea rates in the US population aged 15 to 39 years for the period 2000 to 2015 and estimated the impact that alternative screening strategies might have had over the same period.

METHODS

We developed a national-level transmission model that divides the population by race/ethnicity, preferred gender of sex partners, age, gender, and sexual activity level. We compared our fitted model ("base case") to 4 alternative strategies: (i) no screening, (ii) full adherence to current screening guidelines, (iii) annual universal screening, or (iv) enhanced screening in groups with the highest infection burden. Main outcomes were incidence, infections averted, and incidence rate ratios by race/ethnicity. Mean values and 95% credible intervals were calculated from 1000 draws from parameter posterior distributions.

RESULTS

The calibrated model reproduced observed trends in gonorrhea, including disparities in infection burden by race/ethnicity. We estimated that screening for gonorrhea from 2000 to 2015 averted 30% (95% credible intervals, 18-44%) of total infections that would otherwise have occurred. All alternative active screening strategies were estimated to further reduce, but not eliminate, gonorrhea infections relative to the base case, with differential impacts on the subpopulations of interest.

CONCLUSIONS

Our model results suggest that screening has reduced gonorrhea incidence in the US population. Additional reductions in infection burden may have been possible over this period with increased screening, but elimination was unlikely.

Human Papillomavirus Vaccination for Adults: Updated Recommendations of the Advisory Committee on Immunization Practices

Vaccination against human papillomavirus (HPV) is recommended to prevent new HPV infections and HPV-associated diseases, including some cancers. The Advisory Committee on Immunization Practices (ACIP)* routinely recommends HPV vaccination at age 11 or 12 years; vaccination can be given starting at age 9 years. Catch-up vaccination has been recommended since 2006 for females through age 26 years, and since 2011 for males through age 21 years and certain special populations through age 26 years. This report updates ACIP catch-up HPV vaccination recommendations and guidance published in 2014, 2015, and 2016 (1-3). Routine recommendations for vaccination of adolescents have not changed. In June 2019, ACIP recommended catch-up HPV vaccination for all persons through age 26 years. ACIP did not recommend catch-up vaccination for all adults aged 27 through 45 years, but recognized that some persons who are not adequately vaccinated might be at risk for new HPV infection and might benefit from vaccination in this age range; therefore, ACIP recommended shared clinical decision-making regarding potential HPV vaccination for these persons.

State policies in the United States impacting drug-related convictions and their consequences in 2015

Background

Criminal justice system involvement has been associated with health issues, including sexually transmitted disease. Both incarceration and sexually transmitted disease share associations with various social conditions, including poverty, stigma, and drug use.

Methods

United States state laws (including Washington, D.C.) regarding drug possession and consequences of drug-related criminal convictions were collected and coded. Drug possession policies focused on mandatory sentences for possession of marijuana, crack cocaine and methamphetamines. Consequences of drug-related convictions included ineligibility for public programmes, ineligibility for occupational licences and whether employers may ask prospective employees about criminal history. We analysed correlations between state sexually transmitted disease rates and percentage of a state's population convicted of a felony.

Results

First-time possession of marijuana results in mandatory incarceration in one state; first-time possession of crack cocaine or methamphetamines results in mandatory incarceration in 12 (23.5%) states. Many states provide enhanced punishment upon a third possession conviction. A felony drug conviction results in mandatory ineligibility for the Supplemental Nutrition Assistance Program and/or Temporary Assistance for Needy Families in 17 (33.3%) states. Nine (17.6%) states prohibit criminal history questions on job applications. Criminal convictions limit eligibility for various professional licences in all states. State chlamydia, gonorrhoea and syphilis rates were positively associated with the percentage of the state population convicted of a felony (p < 0.05).

Conclusion

While associations between crime, poverty, stigma and health have been investigated, our findings could be used to investigate the relationship between the likelihood of criminal justice system interactions, their consequences and public health outcomes including sexually transmitted disease risk.

Updated medical care cost estimates for HPV-associated cancers: implications for cost-effectiveness analyses of HPV vaccination in the United States

Estimates of medical care costs for cervical and other cancers associated with human papillomavirus (HPV) are higher in studies published in recent years than in studies published before 2012. The purpose of this report is (1) to review and summarize the recent cancer cost estimates and (2) to illustrate how the estimated cost-effectiveness of HPV vaccination might change when these recent cost estimates are applied. Our literature search yielded 6 studies that provided updated medical care cost estimates for 5 HPV-associated cancers. We found that applying the current cancer cost estimates had a notable impact on the estimated medical costs averted by HPV vaccination over an extended time frame (100 years), and a moderate impact on the estimated cost per quality-adjusted life year (QALY) gained by HPV vaccination. For example, for catch-up vaccination of teenagers and young adults, applying the more recent cancer costs reduced the estimated cost per QALY gained by about $12,400. The cost studies we identified in our literature review are up-to-date and based on reliable data sources from United States settings, and can inform future studies of HPV vaccination cost-effectiveness in the United States. However, careful consideration is warranted to determine the most appropriate cost values to apply.

Disparities in Incidence of Human Immunodeficiency Virus Infection Among Black and White Women - United States, 2010-2016

Incident human immunodeficiency virus (HIV) infections among adolescent females and women declined during 2010-2016, with the largest decrease (21%) occurring among black women (1). However, in 2016, although black women accounted for 13% of the U.S. female population, 60% of new HIV infections among women were in black women, indicating persisting disparities (1). CDC used the population attributable proportion (PAP) disparity measure to describe the proportional decrease in HIV infection among black and white women combined that would be realized if the group with the higher rate (blacks) had the same rate as did the group with the lower rate (whites) (2). Analyses indicated that an estimated 3,900 of 4,200 (93%) incident HIV infections among black women in 2016 would not have occurred if rates were the same for black and white women. The PAP disparity measure decreased from 0.75 in 2010 to 0.70 in 2016, suggesting that if incidence rates for black women were the same as those for white women, the annual number of incident HIV infections among black and white women would have been 75% lower in 2010 and 70% lower in 2016. Continued efforts are needed to identify and address social and structural determinants associated with HIV-related disparities to eliminate these disparities and decrease HIV incidence among black women.

The Impact of Screening and Partner Notification on Chlamydia Prevalence and Numbers of Infections Averted in the United States, 2000-2015: Evaluation of Epidemiologic Trends Using a Pair-Formation Transmission Model

Population-level effects of control strategies on the dynamics of Chlamydia trachomatis transmission are difficult to quantify. In this study, we calibrated a novel sex- and age-stratified pair-formation transmission model of chlamydial infection to epidemiologic data in the United States for 2000–2015. We used sex- and age-specific prevalence estimates from the National Health and Nutrition Examination Surveys, case report data from national chlamydia surveillance, and survey data from the Youth Risk Behavior Survey on the proportion of the sexually active population aged 15–18 years. We were able to reconcile national prevalence estimates and case report data by allowing for changes over time in screening coverage and reporting completeness. In retrospective analysis, chlamydia prevalence was estimated to be almost twice the current levels in the absence of screening and partner notification. Although chlamydia screening and partner notification were both found to reduce chlamydia burden, the relative magnitude of their estimated impacts varied in our sensitivity analyses. The variation in the model predictions highlights the need for further data collection and research to improve our understanding of the natural history of chlamydia and the pathways through which prevention strategies affect transmission dynamics.

Impacts of Federal Prevention Funding on Reported Gonorrhea and Chlamydia Rates

INTRODUCTION

The Centers for Disease Control and Prevention allocates funds annually to jurisdictions nationwide for sexually transmitted infection prevention activities. The objective of this study was to assess the effectiveness of federal sexually transmitted infection prevention funding for reducing rates of reported sexually transmitted infections.

METHODS

In 2017-2018, finite distributed lag regression models were estimated to assess the impact of sexually transmitted infection prevention funding (in 2016 dollars per capita) on reported chlamydia rates from 2000 to 2016 and reported gonorrhea rates from 1981 to 2016. Including lagged funding measures allowed for assessing the impact of funding over time. Controls for state-level socioeconomic factors, such as poverty rates, were included.

RESULTS

Results from the main model indicate that a 1% increase in annual funding would cumulatively decrease chlamydia and gonorrhea rates by 0.17% (p<0.10) and 0.33% (p<0.05), respectively. Results were similar when stratified by sex, with significant decreases in rates of reported chlamydia and gonorrhea in males of 0.33% and 0.34% (both p<0.05) respectively, and in rates of reported gonorrhea in females of 0.32% (p<0.05). The results were generally consistent across alternative model specifications and other robustness tests.

CONCLUSIONS

The significant inverse associations between federal sexually transmitted infection prevention funding and rates of reported chlamydia and gonorrhea suggest that federally funded sexually transmitted infection prevention activities have a discernable effect on reducing the burden of sexually transmitted infections. The reported sexually transmitted infection rate in a given year depends more on prevention funding in previous years than on prevention funding in the current year, demonstrating the importance of accounting for lagged funding effects.

Cost-effectiveness of adult vaccinations: A systematic review

BACKGROUND

Coverage levels for many recommended adult vaccinations are low. The cost-effectiveness research literature on adult vaccinations has not been synthesized in recent years, which may contribute to low awareness of the value of adult vaccinations and to their under-utilization. We assessed research literature since 1980 to summarize economic evidence for adult vaccinations included on the adult immunization schedule.

METHODS

We searched PubMed, EMBASE, EconLit, and Cochrane Library from 1980 to 2016 and identified economic evaluation or cost-effectiveness analysis for vaccinations targeting persons aged ≥18 years in the U.S. or Canada. After excluding records based on title and abstract reviews, the remaining publications had a full-text review from two independent reviewers, who extracted economic values that compared vaccination to "no vaccination" scenarios.

RESULTS

The systematic searches yielded 1688 publications. After removing duplicates, off-topic publications, and publications without a "no vaccination" comparison, 78 publications were included in the final analysis (influenza = 25, pneumococcal = 18, human papillomavirus = 9, herpes zoster = 7, tetanus-diphtheria-pertussis = 9, hepatitis B = 9, and multiple vaccines = 1). Among outcomes assessing age-based vaccinations, the percent indicating cost-savings was 56% for influenza, 31% for pneumococcal, and 23% for tetanus-diphtheria-pertussis vaccinations. Among age-based vaccination outcomes reporting $/QALY, the percent of outcomes indicating a cost per QALY of ≤$100,000 was 100% for influenza, 100% for pneumococcal, 69% for human papillomavirus, 71% for herpes zoster, and 50% for tetanus-diphtheria-pertussis vaccinations.

CONCLUSIONS

The majority of published studies report favorable cost-effectiveness profiles for adult vaccinations, which supports efforts to improve the implementation of adult vaccination recommendations.

Cost-effectiveness of nonavalent HPV vaccination among males aged 22 through 26 years in the United States

INTRODUCTION

In the United States, routine human papillomavirus (HPV) vaccination is recommended for females and males at age 11 or 12 years; the series can be started at age 9 years. Vaccination is also recommended for females through age 26 years and males through age 21 years. The objective of this study was to assess the health impact and cost-effectiveness of harmonizing female and male vaccination recommendations by increasing the upper recommended catch-up age of HPV vaccination for males from age 21 to age 26 years.

METHODS

We updated a published model of the health impact and cost-effectiveness of 9-valent human papillomavirus vaccine (9vHPV). We examined the cost-effectiveness of (1) 9vHPV for females aged 12 through 26 years and males aged 12 through 21 years, and (2) an expanded program including males through age 26 years.

RESULTS

Compared to no vaccination, providing 9vHPV for females aged 12 through 26 years and males aged 12 through 21 years cost an estimated $16,600 (in 2016 U.S. dollars) per quality-adjusted life year (QALY) gained. The estimated cost per QALY gained by expanding male vaccination through age 26 years was $228,800 and ranged from $137,900 to $367,300 in multi-way sensitivity analyses.

CONCLUSIONS

The cost-effectiveness ratios we estimated are not so favorable as to make a strong economic case for recommending expanding male vaccination, yet are not so unfavorable as to preclude consideration of expanding male vaccination. The wide range of plausible results we obtained may underestimate the true degree of uncertainty, due to model limitations. For example, the cost per QALY might be less than our lower bound estimate of $137,900 had our model allowed for vaccine protection against re-infection. Models that specifically incorporate men who have sex with men (MSM) are needed to provide a more comprehensive assessment of male HPV vaccination strategies.

Review of mathematical models of HSV-2 vaccination: Implications for vaccine development

Development of a vaccine against herpes simplex virus type 2 (HSV-2), a life-long sexually-transmitted infection (STI), would be a major step forward in improving global sexual and reproductive health. In this review, we identified published literature of dynamic mathematical models assessing the impact of either prophylactic or therapeutic HSV-2 vaccination at the population level. We compared each study's model structure and assumptions as well as predicted vaccination impact. We examined possible causes of heterogeneity across model predictions, key gaps, and the implications of these findings for future modelling efforts. Only eight modelling studies have assessed the potential public health impact of HSV-2 vaccination, with the majority focusing on impact of prophylactic vaccines. The studies showed that even an imperfect prophylactic HSV-2 vaccine could have an important public health impact on HSV-2 incidence, and could also impact HIV indirectly in high HIV prevalence settings. Therapeutic vaccines also may provide public health benefits, though they have been explored less extensively. However, there was substantial variation in predicted population-level impact for both types of vaccine, reflecting differences in assumptions between model scenarios. Importantly, many models did not account for heterogeneity in infection rates such as by age, sex and sexual activity. Future modelling work to inform decisions on HSV vaccine development and implementation should consider cost-effectiveness, account for additional HSV-2 sequelae such as neonatal transmission, and model greater heterogeneity in infection rates between individuals, more realistic vaccine deployment, and more thorough sensitivity and uncertainty analyses.

Impact of Rapid Susceptibility Testing and Antibiotic Selection Strategy on the Emergence and Spread of Antibiotic Resistance in Gonorrhea

Background

Increasing antibiotic resistance limits treatment options for gonorrhea. We examined the impact of a hypothetical point-of-care (POC) test reporting antibiotic susceptibility profiles on slowing resistance spread.

Methods

A mathematical model describing gonorrhea transmission incorporated resistance emergence probabilities and fitness costs associated with resistance based on characteristics of ciprofloxacin (A), azithromycin (B), and ceftriaxone (C). We evaluated time to 1% and 5% prevalence of resistant strains among all isolates with the following: (1) empiric treatment (B and C), and treatment guided by POC tests determining susceptibility to (2) A only and (3) all 3 antibiotics.

Results

Continued empiric treatment without POC testing was projected to result in >5% of isolates being resistant to both B and C within 15 years. Use of either POC test in 10% of identified cases delayed this by 5 years. The 3 antibiotic POC test delayed the time to reach 1% prevalence of triply-resistant strains by 6 years, whereas the A-only test resulted in no delay. Results were less sensitive to assumptions about fitness costs and test characteristics with increasing test uptake.

Conclusions

Rapid diagnostics reporting antibiotic susceptibility may extend the usefulness of existing antibiotics for gonorrhea treatment, but ongoing monitoring of resistance patterns will be critical.

Trends in Selected Measures of Racial and Ethnic Disparities in Gonorrhea and Syphilis in the United States, 1981-2013

BACKGROUND

The purpose of this study was to examine selected measures of racial and ethnic disparities in the reported incidence of syphilis and gonorrhea from 1981 to 2013 in the United States.

METHODS

For each year, from 1981 to 2013, we calculated values for 5 disparity measures (Gini coefficient, 2 versions of the index of disparity, population attributable proportion, and the black-to-white rate ratio) for 5 racial/ethnic categories (non-Hispanic white, non-Hispanic black, Hispanic, American Indian/Alaska Native, and Asian/Pacific Islander). We also examined annual and 5-year changes to see if the disparity measures agreed on the direction of change in disparity.

RESULTS

With a few exceptions, the disparity measures increased from 1981 to 1993 and decreased from 1993 to 2013, whereas syphilis and gonorrhea rates decreased for most groups from 1981 to 1993 and increased from 1993 to 2013. Overall, the disparity measures we examined were highly correlated with one another, particularly when examining 5-year changes rather than annual changes in disparity. For example, all 5 measures agreed on the direction of change in the disparity of syphilis in 56% of the annual comparisons and in 82% of the 5-year comparisons.

CONCLUSIONS

Although the disparity measures we examined were generally consistent with one another, these measures can sometimes yield divergent assessments of whether racial/ethnic disparities are increasing or decreasing for a given sexually transmitted disease from one point in time to another, as well as divergent assessments of the relative magnitude of the change.

State-level gonorrhea rates and expedited partner therapy laws: insights from time series analyses

OBJECTIVE

In this study, we examined state-level monthly gonorrhea morbidity and assessed the potential impact of existing expedited partner therapy (EPT) laws in relation to the time that the laws were enacted.

STUDY DESIGN

Longitudinal study.

METHODS

We obtained state-level monthly gonorrhea morbidity (number of cases/100,000 for males, females and total) from the national surveillance data. We used visual examination (of morbidity trends) and an autoregressive time series model in a panel format with intervention (interrupted time series) analysis to assess the impact of state EPT laws based on the months in which the laws were enacted.

RESULTS

For over 84% of the states with EPT laws, the monthly morbidity trends did not show any noticeable decreases on or after the laws were enacted. Although we found statistically significant decreases in gonorrhea morbidity within four of the states with EPT laws (Alaska, Illinois, Minnesota, and Vermont), there were no significant decreases when the decreases in the four states were compared contemporaneously with the decreases in states that do not have the laws.

CONCLUSION

We found no impact (decrease in gonorrhea morbidity) attributable exclusively to the EPT law(s). However, these results do not imply that the EPT laws themselves were not effective (or failed to reduce gonorrhea morbidity), because the effectiveness of the EPT law is dependent on necessary intermediate events/outcomes, including sexually transmitted infection service providers' awareness and practice, as well as acceptance by patients and their partners.

Assessing the Effect of Potential Reductions in Non-Hepatic Mortality on the Estimated Cost-Effectiveness of Hepatitis C Treatment in Early Stages of Liver Disease

BACKGROUND

Most cost-effectiveness analyses of hepatitis C (HCV) therapy focus on the benefits of reducing liver-related morbidity and mortality.

OBJECTIVES

Our objective was to assess how cost-effectiveness estimates of HCV therapy can vary depending on assumptions regarding the potential impact of HCV therapy on non-hepatic mortality.

METHODS

We adapted a state-transition model to include potential effects of HCV therapy on non-hepatic mortality. We assumed successful treatment could reduce non-hepatic mortality by as little as 0 % to as much as 100 %. Incremental cost-effectiveness ratios were computed comparing immediate treatment versus delayed treatment and comparing immediate treatment versus non-treatment.

RESULTS

Comparing immediate treatment versus delayed treatment, when we included a 44 % reduction in non-hepatic mortality following successful HCV treatment, the incremental cost per quality-adjusted life year (QALY) gained by HCV treatment fell by 76 % (from US$314,100 to US$76,900) for patients with no fibrosis and by 43 % (from US$62,500 to US$35,800) for patients with moderate fibrosis. Comparing immediate treatment versus non-treatment, assuming a 44 % reduction in non-hepatic mortality following successful HCV treatment, the incremental cost per QALY gained by HCV treatment fell by 64 % (from US$186,700 to US$67,300) for patients with no fibrosis and by 27 % (from US$35,000 to US$25,500) for patients with moderate fibrosis.

CONCLUSION

Including reductions in non-hepatic mortality from HCV treatment can have substantial effects on the estimated cost-effectiveness of treatment.

Population-level impact, herd immunity, and elimination after human papillomavirus vaccination: a systematic review and meta-analysis of predictions from transmission-dynamic models

BACKGROUND

Modelling studies have been widely used to inform human papillomavirus (HPV) vaccination policy decisions; however, many models exist and it is not known whether they produce consistent predictions of population-level effectiveness and herd effects. We did a systematic review and meta-analysis of model predictions of the long-term population-level effectiveness of vaccination against HPV 16, 18, 6, and 11 infection in women and men, to examine the variability in predicted herd effects, incremental benefit of vaccinating boys, and potential for HPV-vaccine-type elimination.

METHODS

We searched MEDLINE and Embase for transmission-dynamic modelling studies published between Jan 1, 2009, and April 28, 2015, that predicted the population-level impact of vaccination on HPV 6, 11, 16, and 18 infections in high-income countries. We contacted authors to determine whether they were willing to produce new predictions for standardised scenarios. Strategies investigated were girls-only vaccination and girls and boys vaccination at age 12 years. Base-case vaccine characteristics were 100% efficacy and lifetime protection. We did sensitivity analyses by varying vaccination coverage, vaccine efficacy, and duration of protection. For all scenarios we pooled model predictions of relative reductions in HPV prevalence (RRprev) over time after vaccination and summarised results using the median and 10th and 90th percentiles (80% uncertainty intervals [UI]).

FINDINGS

16 of 19 eligible models from ten high-income countries provided predictions. Under base-case assumptions, 40% vaccination coverage and girls-only vaccination, the RRprev of HPV 16 among women and men was 0·53 (80% UI 0·46-0·68) and 0·36 (0·28-0·61), respectively, after 70 years. With 80% girls-only vaccination coverage, the RRprev of HPV 16 among women and men was 0·93 (0·90-1·00) and 0·83 (0·75-1·00), respectively. Vaccinating boys in addition to girls increased the RRprev of HPV 16 among women and men by 0·18 (0·13-0·32) and 0·35 (0·27-0·39) for 40% coverage, and 0·07 (0·00-0·10) and 0·16 (0·01-0·25) for 80% coverage, respectively. The RRprev were greater for HPV 6, 11, and 18 than for HPV 16 for all scenarios investigated. Finally at 80% coverage, most models predicted that girls and boys vaccination would eliminate HPV 6, 11, 16, and 18, with a median RRprev of 1·00 for women and men for all four HPV types. Variability in pooled findings was low, but increased with lower vaccination coverage and shorter vaccine protection (from lifetime to 20 years).

INTERPRETATION

Although HPV models differ in structure, data used for calibration, and settings, our population-level predictions were generally concordant and suggest that strong herd effects are expected from vaccinating girls only, even with coverage as low as 20%. Elimination of HPV 16, 18, 6, and 11 is possible if 80% coverage in girls and boys is reached and if high vaccine efficacy is maintained over time.

FUNDING

Canadian Institutes of Health Research.

The impact and cost-effectiveness of nonavalent HPV vaccination in the United States: Estimates from a simplified transmission model

INTRODUCTION

The objective of this study was to assess the incremental costs and benefits of the 9-valent HPV vaccine (9vHPV) compared with the quadrivalent HPV vaccine (4vHPV). Like 4vHPV, 9vHPV protects against HPV types 6, 11, 16, and 18. 9vHPV also protects against 5 additional HPV types 31, 33, 45, 52, and 58.

METHODS

We adapted a previously published model of the impact and cost-effectiveness of 4vHPV to include the 5 additional HPV types in 9vHPV. The vaccine strategies we examined were (1) 4vHPV for males and females; (2) 9vHPV for females and 4vHPV for males; and (3) 9vHPV for males and females. In the base case, 9vHPV cost $13 more per dose than 4vHPV, based on available vaccine price information.

RESULTS

Providing 9vHPV to females compared with 4vHPV for females (assuming 4vHPV for males in both scenarios) was cost-saving regardless of whether or not cross-protection for 4vHPV was assumed. The cost per quality-adjusted life year (QALY) gained by 9vHPV for both sexes (compared with 4vHPV for both sexes) was < $0 (cost-saving) when assuming no cross-protection for 4vHPV and $8,600 when assuming cross-protection for 4vHPV.

CONCLUSIONS

Compared with a vaccination program of 4vHPV for both sexes, a vaccination program of 9vHPV for both sexes can improve health outcomes and can be cost-saving.

Comparison of 2-Dose and 3-Dose 9-Valent Human Papillomavirus Vaccine Schedules in the United States: A Cost-effectiveness Analysis

A recent clinical trial using the 9-valent human papillomavirus virus (HPV) vaccine has shown that antibody responses after 2 doses are noninferior to those after 3 doses, suggesting that 2 and 3 doses may have comparable vaccine efficacy. We used an individual-based transmission-dynamic model to compare the population-level effectiveness and cost-effectiveness of 2- and 3-dose schedules of 9-valent HPV vaccine in the United States. Our model predicts that if 2 doses of 9-valent vaccine protect for ≥20 years, the additional benefits of a 3-dose schedule are small as compared to those of 2-dose schedules, and 2-dose schedules are likely much more cost-efficient than 3-dose schedules.

Racial and ethnic disparities in human papillomavirus-associated cancer burden with first-generation and second-generation human papillomavirus vaccines

BACKGROUND

In the United States, the burden of human papillomavirus (HPV)-associated cancers varies by racial/ethnic group. HPV vaccination may provide opportunities for primary prevention of these cancers. Herein, the authors projected changes in HPV-associated cancer burden among racial/ethnic groups under various coverage assumptions with the available first-generation and second-generation HPV vaccines to evaluate changes in racial/ethnic disparities.

METHODS

Cancer-specific mathematical models simulated the burden of 6 HPV-associated cancers. Model parameters, informed using national registries and epidemiological studies, reflected sex-specific, age-specific, and racial/ethnic-specific heterogeneities in HPV type distribution, cancer incidence, stage of disease at detection, and mortality. Model outcomes included the cumulative lifetime risks of developing and dying of 6 HPV-associated cancers. The level of racial/ethnic disparities was evaluated under each alternative HPV vaccine scenario using several metrics of social group disparity.

RESULTS

HPV vaccination is expected to reduce the risks of developing and dying of HPV-associated cancers in all racial/ethnic groups as well as reduce the absolute degree of disparities. However, alternative metrics suggested that relative disparities would persist and in some scenarios worsen. For example, when assuming high uptake with the second-generation HPV vaccine, the lifetime risk of dying of an HPV-associated cancer for males decreased by approximately 60%, yet the relative disparity increased from 3.0 to 3.9.

CONCLUSIONS

HPV vaccines are expected to reduce the overall burden of HPV-associated cancers for all racial/ethnic groups and to reduce the absolute disparity gap. However, even with the second-generation vaccine, relative disparities will likely still exist and may widen if the underlying causes of these disparities remain unaddressed. Cancer 2016;122:2057-66. © 2016 American Cancer Society.

Estimating the Population Sizes of Men Who Have Sex With Men in US States and Counties Using Data From the American Community Survey

Background

In the United States, male-to-male sexual transmission accounts for the greatest number of new human immunodeficiency virus (HIV) diagnoses and a substantial number of sexually transmitted infections (STI) annually. However, the prevalence and annual incidence of HIV and other STIs among men who have sex with men (MSM) cannot be estimated in local contexts because demographic data on sexual behavior, particularly same-sex behavior, are not routinely collected by large-scale surveys that allow analysis at state, county, or finer levels, such as the US decennial census or the American Community Survey (ACS). Therefore, techniques for indirectly estimating population sizes of MSM are necessary to supply denominators for rates at various geographic levels.

Objective

Our objectives were to indirectly estimate MSM population sizes at the county level to incorporate recent data estimates and to aggregate county-level estimates to states and core-based statistical areas (CBSAs).

Methods

We used data from the ACS to calculate a weight for each county in the United States based on its relative proportion of households that were headed by a male who lived with a male partner, compared with the overall proportion among counties at the same level of urbanicity (ie, large central metropolitan county, large fringe metropolitan county, medium/small metropolitan county, or nonmetropolitan county). We then used this weight to adjust the urbanicity-stratified percentage of adult men who had sex with a man in the past year, according to estimates derived from the National Health and Nutrition Examination Survey (NHANES), for each county. We multiplied the weighted percentages by the number of adult men in each county to estimate its number of MSM, summing county-level estimates to create state- and CBSA-level estimates. Finally, we scaled our estimated MSM population sizes to a meta-analytic estimate of the percentage of US MSM in the past 5 years (3.9%).

Results

We found that the percentage of MSM among adult men ranged from 1.5% (Wyoming) to 6.0% (Rhode Island) among states. Over one-quarter of MSM in the United States resided in 1 of 13 counties. Among counties with over 300,000 residents, the five highest county-level percentages of MSM were San Francisco County, California at 18.5% (66,586/359,566); New York County, New York at 13.8% (87,556/635,847); Denver County, Colorado at 10.5% (25,465/243,002); Multnomah County, Oregon at 9.9% (28,949/292,450); and Suffolk County, Massachusetts at 9.1% (26,338/289,634). Although California (n=792,750) and Los Angeles County (n=251,521) had the largest MSM populations of states and counties, respectively, the New York City-Newark-Jersey City CBSA had the most MSM of all CBSAs (n=397,399).

Conclusions

We used a new method to generate small-area estimates of MSM populations, incorporating prior work, recent data, and urbanicity-specific parameters. We also used an imputation approach to estimate MSM in rural areas, where same-sex sexual behavior may be underreported. Our approach yielded estimates of MSM population sizes within states, counties, and metropolitan areas in the United States, which provide denominators for calculation of HIV and STI prevalence and incidence at those geographic levels.

Impact and Cost-effectiveness of 3 Doses of 9-Valent Human Papillomavirus (HPV) Vaccine Among US Females Previously Vaccinated With 4-Valent HPV Vaccine

BACKGROUND

We estimated the potential impact and cost-effectiveness of providing 3-doses of nonavalent human papillomavirus (HPV) vaccine (9vHPV) to females aged 13-18 years who had previously completed a series of quadrivalent HPV vaccine (4vHPV), a strategy we refer to as "additional 9vHPV vaccination."

METHODS

We used 2 distinct models: (1) the simplified model, which is among the most basic of the published dynamic HPV models, and (2) the US HPV-ADVISE model, a complex, stochastic, individual-based transmission-dynamic model.

RESULTS

When assuming no 4vHPV cross-protection, the incremental cost per quality-adjusted life-year (QALY) gained by additional 9vHPV vaccination was $146 200 in the simplified model and $108 200 in the US HPV-ADVISE model ($191 800 when assuming 4vHPV cross-protection). In 1-way sensitivity analyses in the scenario of no 4vHPV cross-protection, the simplified model results ranged from $70 300 to $182 000, and the US HPV-ADVISE model results ranged from $97 600 to $118 900.

CONCLUSIONS

The average cost per QALY gained by additional 9vHPV vaccination exceeded $100 000 in both models. However, the results varied considerably in sensitivity and uncertainty analyses. Additional 9vHPV vaccination is likely not as efficient as many other potential HPV vaccination strategies, such as increasing primary 9vHPV vaccine coverage.

Cost-effectiveness of Chlamydia vaccination programs for young women

A successful vaccine could be a cost-effective addition to current screening practices.

We explored potential cost-effectiveness of a chlamydia vaccine for young women in the United States by using a compartmental heterosexual transmission model. We tracked health outcomes (acute infections and sequelae measured in quality-adjusted life-years [QALYs]) and determined incremental cost-effectiveness ratios (ICERs) over a 50-year analytic horizon. We assessed vaccination of 14-year-old girls and catch-up vaccination for 15–24-year-old women in the context of an existing chlamydia screening program and assumed 2 prevaccination prevalences of 3.2% by main analysis and 3.7% by additional analysis. Estimated ICERs of vaccinating 14-year-old girls were $35,300/QALY by main analysis and $16,200/QALY by additional analysis compared with only screening. Catch-up vaccination for 15–24-year-old women resulted in estimated ICERs of $53,200/QALY by main analysis and $26,300/QALY by additional analysis. The ICER was most sensitive to prevaccination prevalence for women, followed by cost of vaccination, duration of vaccine-conferred immunity, and vaccine efficacy. Our results suggest that a successful chlamydia vaccine could be cost-effective.

Health and Economic Impact of Switching from a 4-Valent to a 9-Valent HPV Vaccination Program in the United States

BACKGROUND

Randomized clinical trials have shown the 9-valent human papillomavirus (HPV) vaccine to be highly effective against types 31/33/45/52/58 compared with the 4-valent. Evidence on the added health and economic benefit of the 9-valent is required for policy decisions. We compare population-level effectiveness and cost-effectiveness of 9- and 4-valent HPV vaccination in the United States.

METHODS

We used a multitype individual-based transmission-dynamic model of HPV infection and disease (anogenital warts and cervical, anogenital, and oropharyngeal cancers), 3% discount rate, and societal perspective. The model was calibrated to sexual behavior and epidemiologic data from the United States. In our base-case, we assumed 95% vaccine-type efficacy, lifelong protection, and a cost/dose of $145 and $158 for the 4- and 9-valent vaccine, respectively. Predictions are presented using the mean (80% uncertainty interval [UI] = 10(th)-90(th) percentiles) of simulations.

RESULTS

Under base-case assumptions, the 4-valent gender-neutral vaccination program is estimated to cost $5500 (80% UI = 2400-9400) and $7300 (80% UI = 4300-11 000)/quality-adjusted life-year (QALY) gained with and without cross-protection, respectively. Switching to a 9-valent gender-neutral program is estimated to be cost-saving irrespective of cross-protection assumptions. Finally, the incremental cost/QALY gained of switching to a 9-valent gender-neutral program (vs 9-valent girls/4-valent boys) is estimated to be $140 200 (80% UI = 4200->1 million) and $31 100 (80% UI = 2100->1 million) with and without cross-protection, respectively. Results are robust to assumptions about HPV natural history, screening methods, duration of protection, and healthcare costs.

CONCLUSIONS

Switching to a 9-valent gender-neutral HPV vaccination program is likely to be cost-saving if the additional cost/dose of the 9-valent is less than $13. Giving females the 9-valent vaccine provides the majority of benefits of a gender-neutral strategy.

Cost-effectiveness of hepatitis C treatment for patients in early stages of liver disease

New treatments for hepatitis C virus (HCV) may be highly effective but are associated with substantial costs that may compel clinicians and patients to consider delaying treatment. This study investigated the cost-effectiveness of these treatments with a focus on patients in early stages of liver disease. We developed a state-transition (or Markov) model to calculate costs incurred and quality-adjusted life-years (QALYs) gained following HCV treatment, and we computed incremental cost-effectiveness ratios (cost per QALY gained, in 2012 US dollars) for treatment at different stages of liver disease versus delaying treatment until the subsequent liver disease stage. Our analysis did not include the potential treatment benefits associated with reduced non-liver-related mortality or preventing HCV transmission. All parameter values, particularly treatment cost, were varied in sensitivity analyses. The base case scenario represented a 55-year-old patient with genotype 1 HCV infection with a treatment cost of $100,000 and treatment effectiveness of 90%. In this scenario, for a 55-year-old patient with moderate liver fibrosis (Metavir stage F2), the cost-effectiveness of immediately initiating treatment at F2 (versus delaying treatment until F3) was $37,300/QALY. For patients immediately treated at F0 (versus delaying treatment until F1), the threshold of treatment costs that yielded $50,000/QALY and $100,000/QALY cost-effectiveness ratios were $22,200 and $42,400, respectively.

CONCLUSION

Immediate treatment of HCV-infected patients with moderate and advanced fibrosis appears to be cost-effective, and immediate treatment of patients with minimal or no fibrosis can be cost-effective as well, particularly when lower treatment costs are assumed.