Delay-adjusted age- and sex-specific case fatality rates for COVID-19 in South Korea: Evolution in the estimated risk of mortality throughout the epidemic

Objectives: The aim of this study was to estimate delay-adjusted case fatality rates (CFRs) for COVID-19 in South Korea, and evaluate how these estimates have evolved over time throughout the epidemic. Methods: Public data from the Korea Centers for Disease Control and Prevention (KCDC) were used to estimate age- and sex-specific CFRs for COVID-19 in South Korea up to June 12, 2020. We applied statistical methods previously developed to adjust for the delay between diagnosis and death, and presented both delay-adjusted and crude (unadjusted) CFRs throughout the epidemic. Results: The overall estimated delay-adjusted CFR was 2.39% (3.05% for males and 1.92% for females). Within each age strata where deaths were reported, males were found to have significantly higher CFRs than females. The estimated CFRs increased substantially from age 60 years in males and from 70 years in females. Both the delay-adjusted and crude CFRs were found to have evolved substantially, particularly early in the epidemic, converging only from mid-April 2020. Conclusions: The CFRs for South Korea provide an estimate of mortality risk in a setting where case ascertainment is likely to be more complete. The evolution in CFRs throughout the epidemic highlights the need for caution when interpreting CFRs calculated at a given time point

Using economic evidence to set healthcare priorities in low-income and lower-middle-income countries: a systematic review of methodological frameworks

Policy makers in low-income and lower-middle-income countries (LMICs) are increasingly looking to develop 'evidence-based' frameworks for identifying priority health interventions. This paper synthesises and appraises the literature on methodological frameworks - which incorporate economic evaluation evidence - for the purpose of setting healthcare priorities in LMICs. A systematic search of Embase, MEDLINE, Econlit and PubMed identified 3968 articles with a further 21 articles identified through manual searching. A total of 36 papers were eligible for inclusion. These covered a wide range of health interventions with only two studies including health systems strengthening interventions related to financing, governance and human resources. A little under half of the studies (39%) included multiple criteria for priority setting, most commonly equity, feasibility and disease severity. Most studies (91%) specified a measure of 'efficiency' defined as cost per disability-adjusted life year averted. Ranking of health interventions using multi-criteria decision analysis and generalised cost-effectiveness were the most common frameworks for identifying priority health interventions. Approximately a third of studies discussed the affordability of priority interventions. Only one study identified priority areas for the release or redeployment of resources. The paper concludes by highlighting the need for local capacity to conduct evaluations (including economic analysis) and empowerment of local decision-makers to act on this evidence

Cost-Effective Strategies for Mitigating a Future Influenza Pandemic with H1N1 2009 Characteristics

Background: We performed an analysis of the cost-effectiveness of pandemic intervention strategies using a detailed, individual-based simulation model of a community in Australia together with health outcome data of infected individuals gathered during 2009–2010. The aim was to examine the cost-effectiveness of a range of interventions to determine the most cost-effective strategies suitable for a future pandemic with H1N1 2009 characteristics. Methodology/Principal Findings: Using transmissibility, age-stratified attack rates and health outcomes determined from H1N1 2009 data, we determined that the most cost-effective strategies involved treatment and household prophylaxis using antiviral drugs combined with limited duration school closure, with costs ranging from $632 to$777 per case prevented. When school closure was used as a sole intervention we found the use of limited duration school closure to be significantly more cost-effective compared to continuous school closure, a result with applicability to countries with limited access to antiviral drugs. Other social distancing strategies, such as reduced workplace attendance, were found to be costly due to productivity losses. Conclusion: The mild severity (low hospitalisation and case fatality rates) and low transmissibility of H1N1 2009 meant that health treatment costs were dominated by the higher productivity losses arising from workplace absence due to illness and childcare requirements following school closure. Further analysis for higher transmissibility but with the same, mild severit

Detecting the start of an influenza outbreak using exponentially weighted moving average charts

Background. Influenza viruses cause seasonal outbreaks in temperate climates, usually during winter and early spring, and are endemic in tropical climates. The severity and length of influenza outbreaks vary from year to year. Quick and reliable detection of the start of an outbreak is needed to promote public health measures. Methods. We propose the use of an exponentially weighted moving average (EWMA) control chart of laboratory confirmed influenza counts to detect the start and end of influenza outbreaks. Results. The chart is shown to provide timely signals in an example application with seven years of data from Victoria, Australia. Conclusions. The EWMA control chart could be applied in other applications to quickly detect influenza outbreaks

Estimation of Influenza Vaccine Effectiveness from Routine Surveillance Data

BACKGROUND: Influenza vaccines are reviewed each year, and often changed, in an effort to maintain their effectiveness against drifted influenza viruses. There is however no regular review of influenza vaccine effectiveness during, or at the end of, Australian influenza seasons. It is possible to use a case control method to estimate vaccine effectiveness from surveillance data when all patients in a surveillance system are tested for influenza and their vaccination status is known. METHODOLOGY/PRINCIPAL FINDINGS: Influenza-like illness (ILI) surveillance is conducted during the influenza season in sentinel general practices scattered throughout Victoria, Australia. Over five seasons 2003-7, data on age, sex and vaccination status were collected and nose and throat swabs were offered to patients presenting within three days of the onset of their symptoms. Swabs were tested using a reverse transcriptase polymerase chain reaction (RT-PCR) test. Those positive for influenza were sent to the World Health Organization (WHO) Collaborating Centre for Reference and Research on Influenza where influenza virus culture and strain identification was attempted. We used a retrospective case control design in five consecutive influenza seasons, and estimated influenza vaccine effectiveness (VE) for patients of all ages to be 53% (95% CI 38-64), but 41% (95% CI 19-57) adjusted for age group and year. The adjusted VE for all adults aged at least 20 years, the age groups for whom a benefit of vaccination could be shown, was 51% (95% CI 34-63). Comparison of VE estimates with vaccine and circulating strain matches across the years did not reveal any significant differences. CONCLUSIONS/SIGNIFICANCE: These estimates support other field studies of influenza vaccine effectiveness, given that theoretical considerations suggest that these values may underestimate true effectiveness, depending on test specificity and the ratio of the influenza ILI attack rate to the non-influenza ILI attack rate. Incomplete recording of vaccination status and under-representation of children in patients from whom a swab was collected limit the data. Improvements have been implemented for prospective studies

Human papillomavirus prevalence among indigenous and non-indigenous Australian women prior to a national HPV vaccination program

<p>Abstract</p> <p>Background</p> <p>Indigenous women in Australia have a disproportionate burden of cervical cancer despite a national cervical screening program. Prior to introduction of a national human papilloma virus (HPV) vaccination program, we determined HPV genotype prevalence by Indigenous status and residence in remote areas.</p> <p>Methods</p> <p>We recruited women aged 17 to 40 years presenting to community-based primary health services for routine Pap screening across Australia. A liquid-based cytology (LBC) cervical specimen was tested for HPV DNA using the AMPLICOR HPV-DNA test and a PGMY09/11-based HPV consensus PCR; positive specimens were typed by reverse hybridization. We calculated age-adjusted prevalence by weighting to relevant population data, and determined predictors of HPV-DNA positivity by age, Indigenous status and area of residence using logistic regression.</p> <p>Results</p> <p>Of 2152 women (655 Indigenous), prevalence of the high-risk HPV genotypes was similar for Indigenous and non-Indigenous women (HPV 16 was 9.4% and 10.5%, respectively; HPV 18 was 4.1% and 3.8%, respectively), and did not differ by age group. In younger age groups, the prevalence of other genotypes also did not differ, but in those aged 31 to 40 years, HPV prevalence was higher for Indigenous women (35% versus 22.5%; <it>P </it>< 0.001), specifically HPV clades α5 (OR = 2.1, 95% CI 1.1 to 4.3) and α7, excluding type 18 (OR 1.9, 95% CI 1.1 to 3.3). In multivariate analysis, detection of any HPV genotype was strongly associated with smoking and Pap-test abnormalities, with both risk factors more common among Indigenous women.</p> <p>Conclusion</p> <p>Although we found no difference in the prevalence of HPV16/18 among Australian women by Indigenous status or, for Indigenous women, residence in remote regions, differences were found in the prevalence of risk factors and some other HPV genotypes. This reinforces the importance of cervical screening as a complement to vaccination for all women, and the value of baseline data on HPV genotype prevalence by Indigenous status and residence for the monitoring of vaccine impact.</p

Human papillomavirus vaccine introduction in low-income and middle-income countries: guidance on the use of cost-effectiveness models

BACKGROUND: The World Health Organization (WHO) recommends that the cost effectiveness of introducing human papillomavirus (HPV) vaccination is considered before such a strategy is implemented. However, developing countries often lack the technical capacity to perform and interpret results of economic appraisals of vaccines. To provide information about the feasibility of using such models in a developing country setting, we evaluated models of HPV vaccination in terms of their capacity, requirements, limitations and comparability. METHODS: A literature review identified six HPV vaccination models suitable for low-income and middle-income country use and representative of the literature in terms of provenance and model structure. Each model was adapted by its developers using standardised data sets representative of two hypothetical developing countries (a low-income country with no screening and a middle-income country with limited screening). Model predictions before and after vaccination of adolescent girls were compared in terms of HPV prevalence and cervical cancer incidence, as was the incremental cost-effectiveness ratio of vaccination under different scenarios. RESULTS: None of the models perfectly reproduced the standardised data set provided to the model developers. However, they agreed that large decreases in type 16/18 HPV prevalence and cervical cancer incidence are likely to occur following vaccination. Apart from the Thai model (in which vaccine and non-vaccine HPV types were combined), vaccine-type HPV prevalence dropped by 75% to 100%, and vaccine-type cervical cancer incidence dropped by 80% to 100% across the models (averaging over age groups). The most influential factors affecting cost effectiveness were the discount rate, duration of vaccine protection, vaccine price and HPV prevalence. Demographic change, access to treatment and data resolution were found to be key issues to consider for models in developing countries. CONCLUSIONS: The results indicated the usefulness of considering results from several models and sets of modelling assumptions in decision making. Modelling groups were prepared to share their models and expertise to work with stakeholders in developing countries. Please see related article: http://www.biomedcentral.com/1741-7007/9/55