Cost-effectiveness and public health benefit of secondary cardiovascular disease prevention from improved adherence using a polypill in the UK.

OBJECTIVE: To evaluate the public health and economic benefits of adherence to a fixed-dose combination polypill for the secondary prevention of cardiovascular (CV) events in adults with a history of myocardial infarction (MI) in the UK. DESIGN: Markov-model-based cost-effectiveness analysis, informed by systematic reviews, which identified efficacy, utilities and adherence data inputs. SETTING: General practice in the UK. PARTICIPANTS: Patients with a mean age of 64.7 years, most of whom are men with a recent or non-recent diagnosis of MI and for whom secondary preventive medication is indicated and well tolerated. INTERVENTION: Fixed-dose combination polypill (100 mg aspirin, 20 mg atorvastatin and 2.5, 5, or 10 mg ramipril) compared with multiple monotherapy. PRIMARY AND SECONDARY OUTCOME MEASURES: CV events prevented per 1000 patients; cost per life-year gained; and cost per quality-adjusted life-year (QALY) gained. RESULTS: The model estimates that for each 10% increase in adherence, an additional 6.7% fatal and non-fatal CV events can be prevented. In the base case, over 10 years, the polypill would improve adherence by ∼20% and thereby prevent 47 of 323 (15%) fatal and non-fatal CV events per 1000 patients compared with multiple monotherapy, with an incremental cost-effectiveness ratio (ICER) of £8200 per QALY gained. Probabilistic sensitivity analyses for the base-case assumptions showed an 81.5% chance of the polypill being cost-effective at a willingness-to-pay threshold of £20,000 per QALY gained compared with multiple monotherapy. In scenario analyses that varied structural assumptions, ICERs ranged between cost saving and £21,430 per QALY gained. CONCLUSIONS: Assuming that some 450,000 adults are at risk of MI, a 10 percentage point uptake of the polypill could prevent 3260 CV events and 590 CV deaths over a decade.The polypill appears to be a cost-effective strategy to prevent fatal and non-fatal CV events in the UK.

Increased uptake and new therapies are needed to avert rising hepatitis C-related end stage liver disease in England: modelling the predicted impact of treatment under different scenarios.

BACKGROUND & AIMS: Hepatitis C (HCV) related disease in England is predicted to rise, and it is unclear whether treatment at current levels will be able to avert this. The aim of this study was to estimate the number of people with chronic HCV infection in England that are treated and assess the impact and costs of increasing treatment uptake. METHODS: Numbers treated were estimated using national data sources for pegylated interferon supplied, dispensed, or purchased from 2006 to 2011. A back-calculation approach was used to project disease burden over the next 30 years and determine outcomes under various scenarios of treatment uptake. RESULTS: 5000 patients were estimated to have been treated in 2011 and 28,000 in total from 2006 to 2011; approximately 3.1% and 17% respectively of estimated chronic infections. Without treatment, incident cases of decompensated cirrhosis and hepatocellular carcinoma were predicted to increase until 2035 and reach 2290 cases per year. Treatment at current levels should reduce incidence by 600 cases per year, with a peak around 2030. Large increases in treatment are needed to halt the rise; and with more effective treatment the best case scenario predicts incidence of around 500 cases in 2030, although treatment uptake must still be increased considerably to achieve this. CONCLUSIONS: If the infected population is left untreated, the number of patients with severe HCV-related disease will continue to increase and represent a substantial future burden on healthcare resources. This can be mitigated by increasing treatment uptake, which will have the greatest impact if implemented quickly.

Mind the gaps: what's missing from current economic evaluations of universal HPV vaccination?

BACKGROUND: Since the original licensing of human papilloma virus (HPV) vaccination for women, evidence is accumulating of its effectiveness in preventing HPV-related conditions in men, and universal vaccination (vaccinating men and women) is now recommended in some countries. Several models of the cost-effectiveness of universal HPV vaccination have been published, but results have been mixed. This article assesses the extent to which economic studies have captured the range of values associated with universal HPV vaccination, and how this influences estimates of its cost-effectiveness. METHODS: Eight published economic evaluations of universal HPV vaccination were reviewed to identify which of the values associated with universal HPV vaccination were included in each analysis. RESULTS: Studies of the cost-effectiveness of universal HPV vaccination capture only a fraction of the values generated. Most studies focused on impacts on health and health system cost, and only captured these partially. A range of values is excluded from most studies, including impacts on productivity, patient time and costs, carers and family costs, and broader social values such as the right to access treatment. Further, those studies that attempted to capture these values only did so partially. DISCUSSION: Decisions to invest in universal HPV vaccination need to be based on a complete assessment of the value that it generates. This is not provided by existing economic evaluations. Further work is required to understand this value. First, research is required to understand how HPV-related health outcomes impact on society including, for instance, their impact on productivity. Second, consideration should be given to alternative approaches to capture this broader set of values in a manner useful to decisions-makers, such as multi-criteria decision analysis.

Potential overestimation of HPV vaccine impact due to unmasking of non-vaccine types: quantification using a multi-type mathematical model.

INTRODUCTION: Estimates of human papillomavirus (HPV) vaccine impact in clinical trials and modelling studies rely on DNA tests of cytology or biopsy specimens to determine the HPV type responsible for a cervical lesion. DNA of several oncogenic HPV types may be detectable in a specimen. However, only one type may be responsible for a particular cervical lesion. Misattribution of the causal HPV type for a particular abnormality may give rise to an apparent increase in disease due to non-vaccine HPV types following vaccination ("unmasking"). METHODS: To investigate the existence and magnitude of unmasking, we analysed data from residual cytology and biopsy specimens in English women aged 20-64 years old using a stochastic type-specific individual-based model of HPV infection, progression and disease. The model parameters were calibrated to data on the prevalence of HPV DNA and cytological lesion of different grades, and used to assign causal HPV types to cervical lesions. The difference between the prevalence of all disease due to non-vaccine HPV types, and disease due to non-vaccine HPV types in the absence of vaccine HPV types, was then estimated. RESULTS: There could be an apparent maximum increase of 3-10% in long-term cervical cancer incidence due to non-vaccine HPV types following vaccination. CONCLUSION: Unmasking may be an important phenomenon in HPV post-vaccination epidemiology, in the same way that has been observed following pneumococcal conjugate vaccination.

Comparing bivalent and quadrivalent human papillomavirus vaccines: economic evaluation based on transmission model.

OBJECTIVES: To compare the effect and cost effectiveness of bivalent and quadrivalent human papillomavirus (HPV) vaccination, taking into account differences in licensure indications, protection against non-vaccine type disease, protection against disease related to HPV types 6 and 11, and reported long term immunogenicity. DESIGN: A model of HPV transmission and disease previously used to inform UK vaccination policy, updated with recent evidence and expanded to include scenarios where the two vaccines differ in duration of protection, cross protection, and end points prevented. SETTING: United Kingdom. Population Males and females aged 12-75 years. MAIN OUTCOME MEASURE: Incremental cost effectiveness ratios for both vaccines and additional cost per dose for the quadrivalent vaccine to be equally cost effective as the bivalent vaccine. RESULTS: The bivalent vaccine needs to be cheaper than the quadrivalent vaccine to be equally cost effective, mainly because of its lack of protection against anogenital warts. The price difference per dose ranges from a median of £19 (interquartile range £12-£27) to £35 (£27-£44) across scenarios about vaccine duration, cross protection, and end points prevented (assuming one quality adjusted life year (QALY) is valued at £30,000 and both vaccines can prevent all types of HPV related cancers). CONCLUSIONS: The quadrivalent vaccine may have an advantage over the bivalent vaccine in reducing healthcare costs and QALYs lost. The bivalent vaccine may have an advantage in preventing death due to cancer. However, considerable uncertainty remains about the differential benefit of the two vaccines.

Modelling borderline and mild dysplasia associated with HPV 6 and 11 infection.

INTRODUCTION: Low risk HPV types 6/11 are responsible for some low-grade cytological abnormalities. Most economic analyses of HPV vaccination have estimated the additional benefit of HPV 6/11 protection by the quadrivalent vaccine, over the bivalent, based on reduction of genital warts but have not included reduction in repeat smears and colposcopies due to low-grade abnormalities. We investigate the contribution of HPV types 6/11 to abnormal smears and associated costs in England. METHODS: The risk of borderline or mild dysplasia due to HPV 6/11 infection was estimated from a study of type-specific HPV DNA in cervical screening specimens collected throughout England. A Markov model representing 10 million women with HPV 6/11 or with no HPV infection from 24 to 64 years was developed to estimate the number of abnormal smears, subsequent repeat smears and colposcopies due to HPV 6/11 associated with borderline or mild dysplasia. Fitting was achieved by varying the force of infection, probability of borderline or mild dysplasia if HPV-uninfected or infected with HPV 6/11 and the duration of infection. RESULTS: The relative risks of borderline or mild dysplasia when infected with HPV 6/11 compared to not being HPV infected were 6.32 (95% credible interval 1.56-25.6) and 17.5 (1.02-300) respectively. Using best fitting parameters we find the costs incurred are between £170 and £195 per abnormal smear due to infection with HPV 6/11. CONCLUSIONS: In England, the impact of cytological abnormalities due to HPV 6/11 is relatively small, but not negligible. A vaccine that protects against HPV 6/11 infections could reduce costs associated with borderline and mild dysplasia, and associated colposcopies. These benefits should be considered when formulating immunisation policy, if possible. Smears and colposcopies in those uninfected with HPV far outnumber those in women infected with HPV 6/11.

Prevalence of human papillomavirus antibodies in males and females in England.

BACKGROUND: Most studies of human papillomavirus (HPV) epidemiology have employed DNA testing, which measures current infections. Serum antibodies offer a longer-term marker of infection in individuals who seroconvert and can therefore provide additional information about the exposure of populations to HPV. METHODS: Sera from a population-based sample of males and females aged 10 to 49 years, in England, were tested for type-specific HPV antibodies using a multiplexed competitive Luminex assay and previously defined cutoffs of 20, 16, 20, and 24 mMU mL for HPV 6, 11, 16, and 18, respectively. Seropositivity and geometric mean titers of seropositives were analyzed by HPV type, gender, and age. Catalytic models were developed to explore potential effects of antibody waning over time and changing risk of infection by age-cohort. RESULTS: Seroprevalence for HPV 6, 11, 16, and 18 was 16.4%, 5.7%, 14.7%, and 6.3%, respectively, among females and 7.6%, 2.2%, 5.0%, and 2.0%, respectively, among males. Seroprevalence in females was significantly higher than males (P < 0.001 for all types) and showed a decline in older ages that was not seen in males. There was no evidence of declining antibody titers with increasing age. Model results suggest that cohort effects mediated through changes in sexual behavior better explain the observed trend in seroprevalence than waning antibodies over time. CONCLUSIONS: Preimmunization HPV seroprevalence in England shows similar trends to reports from other developed countries. We find the lower seroprevalence in older females probably reflects changes in sexual behavior over the last few decades. This study provides baseline data to monitor the impact of the immunization programme.