Economic impact of implementing decennial tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccination in adults in the United States.

BACKGROUND: In the United States, persons ≥11 years are recommended to receive one dose of tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccine, followed by decennial tetanus- and diphtheria-toxoid (Td) boosters. Many providers use Tdap instead of Td. We evaluated epidemiologic and economic impacts of replacing Td boosters with Tdap. METHODS: We used a static cohort model to examine replacing Td with Tdap over the lifetime of 4,386,854 adults ≥21 years. Because pertussis is underdiagnosed and true incidence is unknown, we varied incidence from 2.5 cases/100,000 person-years to 500 cases/100,000 person-years. We calculated vaccine and medical costs from claims data. We estimated cost per case prevented and per quality-adjusted life year (QALY) saved; sensitivity analyses were conducted on vaccine effectiveness (VE), protection duration, vaccine cost, disease duration, hospitalization rates, productivity loss and missed work. We did not include programmatic advantages resulting from use of a single tetanus-toxoid containing vaccine. RESULTS: At lowest incidence estimates, administering Tdap resulted in high costs per averted case ($111,540) and QALY saved ($8,972,848). As incidence increased, cases averted increased and cost per QALY saved decreased rapidly. With incidence estimates of 250 cases/100,000 person-years, cost per averted case and QALY saved were $984 and $81,678 respectively; at 500 cases/100,000 person-years, these values were $427 and $35,474. In multivariate sensitivity analyses, assuming 250 cases/100,000 person-years, estimated cost per QALY saved ranged from $971 (most favorable) to $217,370 (least favorable). CONCLUSIONS: Our findings suggest that replacing Td with Tdap for the decennial booster would result in high cost per QALY saved based on reported cases. However, programmatic considerations were not accounted for, and if pertussis incidence, which is incompletely measured, is assumed to be higher than reported through national surveillance, substituting Tdap for Td may lead to moderate decreases in pertussis cases and cost per QALY.

Cost-effectiveness of scaling-up HCV prevention and treatment in the United States for people who inject drugs.

AIMS: To examine the cost-effectiveness of hepatitis C virus (HCV) treatment of people who inject drugs (PWID), combined with medication-assisted treatment (MAT) and syringe-service programs (SSP), to tackle the increasing HCV epidemic in the United States. DESIGN: HCV transmission and disease progression models with cost-effectiveness analysis using a health-care perspective. SETTING: Rural Perry County, KY (PC) and urban San Francisco, CA (SF), USA. Compared with PC, SF has a greater proportion of PWID with access to MAT or SSP. HCV treatment of PWID is negligible in both settings. PARTICIPANTS: PWID data were collected between 1998 and 2015 from Social Networks Among Appalachian People, U Find Out, Urban Health Study and National HIV Behavioral Surveillance System studies. INTERVENTIONS AND COMPARATOR: Three intervention scenarios modeled: baseline-existing SSP and MAT coverage with HCV screening and treatment with direct-acting antiviral for ex-injectors only as per standard of care; intervention 1-scale-up of SSP and MAT without changes to treatment; and intervention 2-scale-up as intervention 1 combined with HCV screening and treatment for current PWID. MEASUREMENTS: Incremental cost-effectiveness ratios (ICERs) and uncertainty using cost-effectiveness acceptability curves. Benefits were measured in quality-adjusted life-years (QALYs). FINDINGS: For both settings, intervention 2 is preferred to intervention 1 and the appropriate comparator for intervention 2 is the baseline scenario. Relative to baseline, for PC intervention 2 averts 1852 more HCV infections, increases QALYS by 3095, costs $21.6 million more and has an ICER of $6975/QALY. For SF, intervention 2 averts 36 473 more HCV infections, increases QALYs by 7893, costs $872 million more and has an ICER of $11 044/QALY. The cost-effectiveness of intervention 2 was robust to several sensitivity analysis. CONCLUSIONS: Hepatitis C screening and treatment for people who inject drugs, combined with medication-assisted treatment and syringe-service programs, is a cost-effective strategy for reducing hepatitis C burden in the United States.

Monitoring the hepatitis C care cascade using administrative claims data.

OBJECTIVES: With the availability of curative therapies, it is important to ensure that individuals infected with hepatitis C virus (HCV) receive recommended testing, care, and treatment. We sought to evaluate insurance claims data as a source for monitoring progression along the HCV care cascade. STUDY DESIGN: Longitudinal evaluation of disease progression, from diagnosis to treatment, among commercially insured enrollees with chronic HCV. METHODS: We validated and used algorithms derived from standardized procedure and diagnosis codes to identify enrollees with chronic HCV in large insurance claims databases to describe the HCV care cascade, including the proportion engaged in HCV-specific care (13 possible definitions), the proportion prescribed HCV treatment, and the proportion who received an HCV RNA test 30 or more days after initiating treatment. RESULTS: Approximately 90% of individuals with an HCV RNA test procedure code followed by either 3 or more chronic HCV diagnosis codes on different service dates or 2 or more chronic HCV diagnosis codes separated by more than 60 days truly had chronic HCV. Using these algorithms, we identified 5791 HCV cases from January 1, 2013, to June 30, 2014. Among enrollees with HCV, 95% were engaged in HCV care, but only 49% initiated treatment and 43% received a follow-up HCV RNA test 30 or more days after initiating treatment. CONCLUSIONS: With validated case-finding algorithms, insurance claims data can be used to describe and monitor portions of the HCV care cascade. Although nearly all enrollees with HCV were engaged in HCV care, only half received treatment, indicating that even commercially insured enrollees may find it challenging to access treatment.

Population-level Outcomes and Cost-Effectiveness of Expanding the Recommendation for Age-based Hepatitis C Testing in the United States.

Background: The US Centers for Disease Control and Prevention and the U.S. Preventive Services Task Force recommend one-time hepatitis C virus (HCV) testing for persons born 1945-1965 and targeted testing for high-risk persons. This strategy targets HCV testing to a prevalent population at high risk for HCV morbidity and mortality, but does not include younger populations with high incidence. To address this gap and improve access to HCV testing, age-based strategies should be considered. Methods: We used a simulation of HCV to estimate the effectiveness and cost-effectiveness of HCV testing strategies: 1) standard of care (SOC) - recommendation for one-time testing for all persons born 1945-1965, 2) recommendation for one-time testing for adults ≥40 years (≥40 strategy), 3) ≥30 years (≥30 strategy), and 4) ≥18 years (≥18 strategy). All strategies assumed targeted testing of high-risk persons. Inputs were derived from national databases, observational cohorts and clinical trials. Outcomes included quality-adjusted life expectancy, costs, and cost-effectiveness. Results: Expanded age-based testing strategies increased US population lifetime case identification and cure rates. Greatest increases were observed in the ≥18 strategy. Compared to the SOC, this strategy resulted in an estimated 256,000 additional infected persons identified and 280,000 additional cures at the lowest cost per QALY gained (ICER = $28,000/QALY). Conclusions: In addition to risk-based testing, one-time HCV testing of persons 18 and older appears to be cost-effective, leads to improved clinical outcomes and identifies more persons with HCV than the current birth cohort recommendations. These findings could be considered for future recommendation revisions.

Human Papillomavirus Vaccine Effectiveness Against Incident Genital Warts Among Female Health-Plan Enrollees, United States.

We examined the effectiveness of human papillomavirus vaccination by dose number and spacing against incident genital warts in a cohort of 64,517 female health-plan enrollees in the United States during 2006-2012. Eligible recipients were classified into groups by regimen: 0, 1, 2 (<6 months apart), 2 (≥6 months apart), or 3 doses. They were followed until a genital wart diagnosis, loss to follow-up, or the end of study. Propensity score weights were used to balance baseline differences across groups. To account for latent genital warts before vaccination, we applied 6- and 12-month buffer periods from last and first vaccine dose, respectively. Incidence rates and hazard ratios were calculated using Poisson regression and Cox models. The propensity score-weighted incidence rate per 100,000 person-years was 762 among unvaccinated participants. Using 6- and 12-month buffer periods, respectively, incidence rates were 641 and 257 for 1 dose, 760 and 577 for the 2-dose (<6-month interval) regimen, 313 and 194 for the 2-dose (≥6-month interval) regimen, and 199 and 162 among 3-dose vaccinees; vaccine effectiveness was 68% and 76% for the 2-dose (≥6-month interval) regimen and 77% and 80% in 3-dose vaccinees compared with unvaccinated participants. Vaccine effectiveness was not significant among vaccinees receiving 1-dose and 2-dose (<6-month interval) regimens compared with unvaccinated participants. Our findings contribute to a better understanding of the real-world effectiveness of HPV vaccination.

Hepatitis C Antibody Testing in a Commercially Insured Population, 2005-2014.

INTRODUCTION: In the U.S., the burden of hepatitis C virus (HCV) infection and associated sequelae is substantial. HCV prevalence is highest among those born in 1945-1965 (Birth Cohort). Newly diagnosed infections are increasing in younger people concurrent with rising opioid/heroin use. The Centers for Disease Control and Prevention (2012) and U.S. Preventive Services Task Force (2013) recommend HCV testing for at-risk individuals and one-time testing for the Birth Cohort. This study describes national trends in HCV antibody testing from 2005 to 2014. METHODS: Using commercial and Medicare supplemental insurance claims data, people were identified who were continuously enrolled for ≥2 years during the 10-year study period, without prior HCV diagnosis (N=190,926,299). Current Procedural Terminology codes identified 3,382,267 unique antibody tests. Temporal trends in annual testing were evaluated using the Cochran-Armitage test, and primary ICD-9-CM diagnosis codes used at the time of testing were described. Data were analyzed in 2015 and 2016. RESULTS: Testing was highest among those aged 18-29 and 30-39 years, increasing by 123% (1.66% to 3.71%) and 108% (1.99% to 4.13%), respectively (p<0.0001). Among the Birth Cohort, there was a 136% increase in HCV antibody testing from 2005 to 2014, with a 91% increase from 1.71% in 2011 to 3.26% 2014 (p<0.0001). CONCLUSIONS: Although the increased HCV antibody testing observed among the Birth Cohort from 2011 to 2014 likely reflects early adoption of updated national testing recommendations, overall testing remains low in this commercially insured population, indicating a clear need for improvement.

Identification and Clinical Management of Persons with Chronic Hepatitis C Virus Infection - Cherokee Nation, 2012-2015.

An estimated 3.5 million persons in the United States are living with hepatitis C virus (HCV) infection, resulting in approximately 20,000 deaths each year, primarily from cirrhosis or hepatocellular carcinoma (1,2). American Indian/Alaska Native (AI/AN) populations have the highest incidence of acute HCV infection among all U.S. racial/ethnic groups and are at greater risk for HCV-related mortality compared with the general population (3). In 2013, new antiviral drugs became available that make possible 8-12 week treatment regimens with fewer adverse events and are able to achieve sustained virologic response (SVR) in >90% of treated patients (4), equivalent to a cure of HCV infection. Also of note, HCV testing recommendations were expanded in 2012 by CDC and in 2013 by the U.S. Preventive Services Task Force to include one-time testing of persons born during 1945-1965 (the "baby boomer" cohort) in addition to anyone at increased risk for HCV infection (5,6). Given the availability of new HCV drugs, expanded testing recommendations, and high incidence of HCV infection in AI/AN populations, in October 2012, Cherokee Nation Health Services (CNHS) implemented a tribal HCV testing policy.* As part of the policy, CNHS added a reminder in the electronic health record (EHR) for clinical decision support and provided HCV education to primary care clinicians. From October 2012 to July 2015, among 92,012 persons with at least one CNHS clinic encounter, the cumulative number who received HCV screening for the first time increased from 3,337 (3.6%) to 16,772 (18.2%). The largest percentage of HCV screening was among persons born during 1945-1965. Of 715 persons who tested positive for HCV antibodies, 488 (68.3%) were tested for HCV RNA; among those 488 persons, 388 (79.5%) were RNA positive and were thus confirmed to have chronic HCV infection. Treatment was initiated for 223 (57.5%) of the 388 with chronic infection; 201 (90.1%) completed treatment, of whom 180 (89.6%) achieved SVR. CNHS has successfully increased HCV testing and treatment and is now collaborating with CDC and other external partners to develop an HCV elimination program for the Cherokee Nation that might serve as a model for similar settings.

Birth Cohort Testing for Hepatitis C Virus - Indian Health Service 2012-2015.

Hepatitis C virus (HCV) infection is a substantial and largely unrecognized public health problem. An estimated 3.5 million persons in the United States are currently living with HCV infection, at least half of whom are unaware of their infection (1-3). Persons born during 1945-1965 (the "baby boomer" birth cohort) have a sixfold higher prevalence (2.6%) than adults of other ages, and represent 81% of all persons chronically infected with HCV (4). Therefore, in addition to recommending testing for all persons at risk for HCV infection, CDC and the U.S. Preventive Services Task Force (USPSTF) recommend one-time HCV testing for the birth cohort (5,6). Compared with the national average, American Indian/Alaska Native (AI/AN) persons have approximately twofold the rate of acute HCV incidence and HCV associated mortality (2). In June 2012, the Indian Health Service (IHS) implemented HCV testing in the 1945-1965 birth cohort and created a nationally standardized performance measure to monitor implementation of the recommendation. As of June 2015, the proportion of the birth cohort screened for HCV increased from a baseline of 7.9% (14,402/182,503) to 32.5% (68,514/211,014) among the AI/AN population served by IHS nationwide; provider training and the use of clinical decision tools were associated with increases in HCV testing. With this fourfold increase in testing in just 3 years, IHS needs to prepare for the challenges associated with increased identification of persons living with HCV infection.

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.

The estimated lifetime probability of acquiring human papillomavirus in the United States.

BACKGROUND: Estimates of the lifetime probability of acquiring human papillomavirus (HPV) can help to quantify HPV incidence, illustrate how common HPV infection is, and highlight the importance of HPV vaccination. METHODS: We developed a simple model, based primarily on the distribution of lifetime numbers of sex partners across the population and the per-partnership probability of acquiring HPV, to estimate the lifetime probability of acquiring HPV in the United States in the time frame before HPV vaccine availability. RESULTS: We estimated the average lifetime probability of acquiring HPV among those with at least 1 opposite sex partner to be 84.6% (range, 53.6%-95.0%) for women and 91.3% (range, 69.5%-97.7%) for men. Under base case assumptions, more than 80% of women and men acquire HPV by age 45 years. CONCLUSIONS: Our results are consistent with estimates in the existing literature suggesting a high lifetime probability of HPV acquisition and are supported by cohort studies showing high cumulative HPV incidence over a relatively short period, such as 3 to 5 years.