Development of a web-based application and multicountry analysis framework for assessing interdicted infections and cost-utility of screening donated blood for HIV, HCV and HBV.

BACKGROUND AND OBJECTIVES: Most countries test donations for HIV, HCV and HBV using serology with or without nucleic acid testing (NAT). Cost-utility analyses provide information on the relative value of different screening options. The aim of this project was to develop an open access risk assessment and cost-utility analysis web-tool for assessing HIV, HCV and HBV screening options (http://www.isbtweb.org/working-parties/transfusion-transmitted-infectious-diseases/). An analysis for six countries (Brazil, Ghana, the Netherlands, South Africa, Thailand and USA) was conducted. MATERIALS AND METHODS: Four strategies; (1) antibody assays (Abs) for HIV and HCV + HBsAg, (2) antibody assays that include antigens for HIV and HCV (Combo) + HBsAg, (3) NAT in minipools of variable size (MP NAT) and (4) individual donation (ID) NAT can be evaluated using the tool. Country-specific data on donors, donation testing results, recipient outcomes and costs are entered using the online interface. Results obtained include the number infections interdicted using each screening options, and the (incremental and average) cost-utility of the options. RESULTS: In each of the six countries evaluated, the use of antibody assays is cost effective or even cost saving. NAT has varying cost-utility depending on the setting, and where adopted, the incremental cost-utility exceeds any previously defined or proposed threshold in each country. CONCLUSION: The web-tool allows an assessment of infectious units interdicted and value for money of different testing strategies. Regardless of gross national income (GNI) per capita, countries appear willing to dedicate healthcare resources to blood supply safety in excess of that for other sectors of health care.

Diagnostic accuracy of culture-based and PCR-based detection tests for methicillin-resistant Staphylococcus aureus: a meta-analysis.

A systematic review and meta-analysis were performed to determine and compare the sensitivity and specificity of PCR-based and culture-based diagnostic tests for methicillin-resistant Staphylococcus aureus (MRSA). Our analysis included 74 accuracy measurements from 29 publications. Nine tests were evaluated: the PCR-based Genotype MRSA Direct and IDI-MRSA, the chromogenic media CHROMagar, Chromogenic MRSA Medium, MRSA ID, MRSA Select and ORSAB, and the nonchromogenic culture media MSA-Cefoxitin and MSA-Oxacillin. For four chromogenic media, incubation periods of 18-24 and 48 h were evaluated. Considerable heterogeneity was detected in most analyses. A significantly higher sensitivity was found for the overall PCR pooled estimate (92.5; 95% CI 87.4-95.9) and the chromogenic media after 48 h of incubation (87.6; 95% CI 82.1-91.6) compared to the overall sensitivity of chromogenic media after 18-24 h (78.3; 95% CI 71.0-84.1). The specificity of chromogenic media after 18-24 h (98.6; 95% CI 97.7-99.1) was higher than the specificity of PCR (97.0; 95% CI 94.5-98.4) but declined after 48 h of incubation (94.7; 95% CI 91.6-96.8).The most sensitive chromogenic medium after 18-24 h of incubation was Chromogenic MRSA Medium (sensitivity: 89.3; 95% CI 72.8-96.3), whereas the most specific chromogenic medium after 18-24 h of incubation was MRSA Select (specificity: 99.4; 95% CI 98.6-99.7). After 48 h of incubation, MRSA Select had the highest sensitivity (93.2; 95% CI 83.5-97.0), whereas CHROMagar had the highest specificity (96.4; 95% CI 91.3-98.5). This meta-analysis showed statistically significant differences in diagnostic accuracy between several of the tests and the test methods evaluated. A reduction of the incubation time of chromogenic media (from 48 to 18-24 h) increases specificity but reduces sensitivity.

The societal burden of HIV/AIDS in Northern Italy: an analysis of costs and quality of life.

This study aims to measure the direct and indirect costs of HIV/AIDS care and quality of life (QoL) of HIV-infected patients in Northern Italy. We conducted a prospective cohort study over 12 months, enrolling a sample of 121 patients with HIV infection from two cities in Northern Italy. Patients were surveyed at baseline and were followed-up at 6 and 12 months. To assess the relationship between costs and stage of disease, patients were categorized into three groups at baseline: "No HAART" (asymptomatic and never before on highly active antiretroviral therapy (HAART)), "Stable HAART" (HAART with mild HIV infection and no prior opportunistic infections) and "HAART failure" (primary HAART regimen was altered because of severe side effects or immunological failure). Direct medical costs were based on utilization of (day) hospital admissions, diagnostic procedures, laboratory tests, clinic visits, consultations and antiretroviral drug use. Indirect costs included production losses due to absence from work, reduced productivity at work and reduced unpaid labour participation. QoL was assessed by visual analogue scale. Parametric regression was used to estimate the expected value and the standard deviation of annual costs per patient. The expected value of total annual costs was 1818 euros and 9820 euros and 12,332 euros, for groups "No HAART", "Stable HAART" and "HAART failure" respectively. We estimated annual expected earnings as 14,994 euros and 10,811 euros and 9820 euros for the same respective groups. The expected value of QoL on a scale of 0-1 in these same patient groups was 0.80, 0.78 and 0.64. We conclude that indirect costs contribute substantially to total costs and are comparable in magnitude to the direct costs excluding antiretroviral drugs. The costs of inpatient care in our cohort were almost negligible compared to total costs. Despite being in treatment, many patients were still gainfully employed and generated substantial expected annual earnings.

Estimation and prediction of the HIV-AIDS-epidemic under conditions of HAART using mixtures of incubation time distributions.

The estimation of the HIV-AIDS epidemic by means of back-calculation (BC) has been difficult since the introduction of highly active anti-retroviral therapy (HAART) because the incubation time distributions needed for BC were poorly known. Moreover, it has been assumed that if the general public is aware that effective treatments are available then the majority of infected people would be known, and therefore a hidden epidemic was assumed not to exist. Nevertheless, it was suspected that not every infected person would come to the attention of health-care providers, and therefore estimates independent of the patients' registration were necessary. In this paper, the incubation time distributions for HIV treated with the HAART regimen are derived from a cohort study. By using estimates of the proportion treated according to the HAART regimen and the incubation time distributions estimated in the era before the implementation of HAART (pre-HAART), new marginal population incubation time distributions for each of the three risk groups (homosexuals, drug users and others) were constructed. The BC was performed using an empirical Bayesian approach based on the latter incubation time distribution.

Enhanced decision support for policy makers using a web interface to health-economic models--illustrated with a cost-effectiveness analysis of nation-wide infant vaccination with the 7-valent pneumococcal conjugate vaccine in the Netherlands.

We have developed a web-based user-interface (web interface) to enhance the usefulness of health-economic evaluations to support decision making (http://pcv.healtheconomics.nl). It allows the user to interact with a health-economic model to evaluate predefined and customized scenarios and perform sensitivity analysis. To explore its usefulness, it was applied to an evaluation of cost-effectiveness of nation-wide infant vaccination with the 7-valent pneumococcal conjugate vaccine (PCV7), that was used to support a policy decision on the inclusion of PCV7 in the national vaccination program (NVP) of the Netherlands. We used a decision-tree analytic model to project the impact of infant vaccination with four doses of PCV7 on an annual cohort of infants born in the Netherlands. The base-case analysis includes the beneficial effects on unvaccinated individuals (herd protection). Additional scenarios varying the number of doses, discount rate for effects and the number of serotypes in the vaccine were evaluated and can be analysed on the web. Our model projects a base-case incremental cost-effectiveness ratio (iCER) of euro14,000 (95% uncertainty interval (UI): 9,800-20,200) per quality adjusted life year (QALY) or euro15,600 (95% UI: 11,100-23,900) per life year gained (LYG).