RESUMO
BACKGROUND: Risk-based decision making is increasingly recognized as key to support national blood policy makers and blood operators concerning the implementation of safety interventions, especially to address emerging infectious threats and new technology opportunities. There is an urgent need for practical decision support tools, especially for low- and middle-income countries that may not have the financial or technical capability to develop risk models. WHO supported the development of such a tool for blood safety. The tool enables users to perform both a quantitative Multi-Criteria Decision Assessment and a novel step-by-step qualitative assessment. STUDY DESIGN AND METHODS: This paper summarizes the content, functionalities, and added value of the new WHO tool. A fictitious case study of a safety intervention to reduce the risk of HIV transmission by transfusion was used to demonstrate the use and usefulness of the tool. RESULTS: Application of the tool highlighted strengths and weaknesses of both the quantitative and qualitative approaches. The quantitative approach facilitates assessment of the robustness of the decision but lacks nuances and interpretability especially when multiple constraints are taken into consideration. Conversely, while unable to provide an assessment of robustness, the step-by-step qualitative approach helps structuring the thought process and argumentation for a preferred intervention in a systematic manner. CONCLUSION: The relative strengths and weaknesses of the quantitative and step-by-step qualitative approach to risk-based decision making are complementary and mutually enhancing. A combination of the two approaches is therefore advisable to support the selection of appropriate blood safety interventions for a particular setting.
Assuntos
Segurança do Sangue , Sistemas de Apoio a Decisões Clínicas , Política de Saúde , Gestão de Riscos/métodos , Doadores de Sangue , Transfusão de Sangue/estatística & dados numéricos , Patógenos Transmitidos pelo Sangue , Sistemas de Apoio a Decisões Clínicas/economia , Estudos de Avaliação como Assunto , Humanos , Infecções/epidemiologia , Mortalidade , Risco , Organização Mundial da SaúdeAssuntos
Bancos de Sangue/organização & administração , Transfusão de Sangue/economia , Bancos de Sangue/economia , Transfusão de Sangue/estatística & dados numéricos , Transfusão de Sangue/tendências , Regulamentação Governamental , Humanos , Obtenção de Tecidos e Órgãos/organização & administração , Estados Unidos , United States Dept. of Health and Human ServicesRESUMO
BACKGROUND: Variant Creutzfeldt-Jakob disease (vCJD) is transmitted by blood transfusion. To mitigate the risk of transfusion-transmitted vCJD (TTvCJD), the US Food and Drug Administration has recommended deferral of potential at-risk blood donors, but some risk remains. We describe a quantitative risk assessment to estimate residual, postdeferral TTvCJD risk in the United States. STUDY DESIGN AND METHODS: We assumed that certain US donors may have acquired vCJD infection through dietary exposure to the agent of bovine spongiform encephalopathy during time spent in the United Kingdom, France, and other countries in Europe. Because of uncertainties regarding the prevalence of vCJD in the United Kingdom, we used both low and high UK prevalence estimates as model inputs. The model estimated the risk of infection from a transfusion in year 2011 and the cumulative risk from 1980 through 2011. The model was validated by comparing the model predictions with reported cases of vCJD. RESULTS: Using the low UK prevalence estimate, the model predicted a mean risk of 1 in 134 million transfusions, zero TTvCJD infections acquired in the year 2011, and zero cumulative clinical TTvCJD cases for the period spanning 1980 to 2011. With the high UK prevalence estimate, the model predicted a mean risk of 1 in 480,000 transfusions, six infections for 2011, and nine cumulative clinical cases from 1980 to 2011. CONCLUSIONS: Model validation exercises indicated that predictions based on the low prevalence estimate are more consistent with clinical cases actually observed to date, implying that the risk, while highly uncertain, is likely very small.
Assuntos
Síndrome de Creutzfeldt-Jakob/transmissão , Transfusão de Eritrócitos/efeitos adversos , Animais , Bovinos , Síndrome de Creutzfeldt-Jakob/epidemiologia , Encefalopatia Espongiforme Bovina/epidemiologia , Encefalopatia Espongiforme Bovina/transmissão , Humanos , Modelos Teóricos , Medição de Risco , Reino Unido/epidemiologia , Estados UnidosAssuntos
Segurança do Sangue/tendências , Doenças Transmissíveis Emergentes/sangue , Animais , Bancos de Sangue/organização & administração , Transfusão de Componentes Sanguíneos/efeitos adversos , Transfusão de Componentes Sanguíneos/métodos , Transfusão de Componentes Sanguíneos/normas , Transfusão de Componentes Sanguíneos/tendências , Segurança do Sangue/métodos , Segurança do Sangue/normas , Canadá/epidemiologia , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/prevenção & controle , Doenças Transmissíveis Emergentes/transmissão , Congressos como Assunto , Seleção do Doador/métodos , Educação , Humanos , Setor Público , Cruz Vermelha/organização & administração , Medição de Risco , Inquéritos e Questionários , Estados Unidos/epidemiologia , United States Food and Drug Administration/organização & administraçãoRESUMO
The need for blood regulation arises from the inherent risks of blood transfusion, which are minimized through implementation of standards. Regulatory oversight is advocated by the World Health Organization (WHO) as an essential element of any blood system to ensure such standards are met. The WHO Blood Regulators Network has developed "Assessment Criteria for National Blood Regulatory Systems" that describe the legal authority and functions of a fully competent blood regulator. The core functions include licensing and/or registration of blood establishments, marketing approval of blood products, oversight of all associated substances and devices, control of clinical trials, access to an independent laboratory for product assessments, lot release, and hemovigilance systems. Regulatory policy-making for blood safety is needed to address emerging threats, to consider the risks and benefits of new products and technologies, and to respond to adverse events. Structured policy-making processes are essential to ensure that decisions are science-based, with appropriate consideration of relevant economic and social factors. Decision making is especially challenging in situations of scientific uncertainty, where prudent precautionary measures may be appropriate based on assessments of risk and feasibility of meaningful interventions. There is international interest in finding a common framework for addressing blood safety decisions.
Assuntos
Doadores de Sangue , Transfusão de Sangue/normas , Seleção do Doador/normas , Guias de Prática Clínica como Assunto/normas , Transfusão de Sangue/métodos , Tomada de Decisões , Seleção do Doador/métodos , Humanos , Formulação de Políticas , Medição de Risco , Inquéritos e Questionários , Organização Mundial da SaúdeRESUMO
There are minimal standards for the processing of whole blood components, and to apply those standards requires a system of quality assurances. Excessive indications of failures in compliance trigger inspections and other remedial actions, but the demarcation of what is excessive is a critical issue. Issues of low volume in some production facilities, low expected frequency of nonconformance, multiple nonindependent statistical tests, and controlling both the false-positive and false-negative rates all complicate quality assurance procedures. The scan statistic is a statistic that computes the number of events in a moving window throughout the period of risk. Monitoring plans based on scan statistics are developed to estimate the probability that a process that is under control.