RESUMO
BACKGROUND: Transfusion-related acute lung injury (TRALI) is a leading cause of transfusion-related mortality. A concern with passive surveillance to detect transfusion reactions is underreporting. Our aim was to obtain evidence-based estimates of TRALI incidence using meta-analysis of active surveillance studies and to compare these estimates with passive surveillance. STUDY DESIGN AND METHODS: We performed a systematic review and meta-analysis of studies reporting TRALI rates. A search of Medline and Embase by a research librarian identified studies published between January 1, 1991 and January 20, 2023. Prospective and retrospective observational studies reporting TRALI by blood component (red blood cells [RBCs], platelets, or plasma) were identified and all inpatient and outpatient settings were eligible. Adult and pediatric, as well as general and specific clinical populations, were included. Platelets and plasma must have used at least one modern TRALI donor risk mitigation strategy. A random effects model estimated TRALI incidence by blood component for active and passive surveillance studies and heterogeneity was examined using meta-regression. RESULTS: Eighty studies were included with approximately 176-million blood components transfused. RBCs had the highest number of studies (n = 66) included, followed by platelets (n = 35) and plasma (n = 34). Pooled TRALI estimates for active surveillance studies were 0.17/10,000 (95% confidence intervals [CI]: 0.03-0.43; I2 = 79%) for RBCs, 0.31/10,000 (95% CI: 0.22-0.42; I2 = <1%) for platelets, and 3.19/10,000 (95% CI: 0.09-10.66; I2 = 86%) for plasma. Studies using passive surveillance ranged from 0.02 to 0.10/10,000 among the various blood components. DISCUSSION: In summary, these estimates may improve a quantitative understanding of TRALI risk, which is important for clinical decision-making weighing the risks and benefits of transfusion.
Assuntos
Lesão Pulmonar Aguda Relacionada à Transfusão , Humanos , Lesão Pulmonar Aguda Relacionada à Transfusão/epidemiologia , Lesão Pulmonar Aguda Relacionada à Transfusão/etiologia , Incidência , Reação Transfusional/epidemiologia , Transfusão de Plaquetas/efeitos adversos , Lesão Pulmonar Aguda/etiologia , Lesão Pulmonar Aguda/epidemiologiaRESUMO
BACKGROUND: The purpose of this scoping review was to identify available sources of evidence on the epidemiology of transfusion-related acute lung injury (TRALI) and whether meta-analysis on the incidence of TRALI is feasible. TRALI is a serious complication and the second leading cause of death related to blood transfusion. Estimates of the incidence of TRALI would provide a useful benchmark for research to reduce TRALI. STUDY DESIGN AND METHODS: We searched the Medline, EMBASE, and PubMed databases for publications related to the incidence of TRALI and hemovigilance. We included all studies irrespective of language or country. Both full-text articles and conference abstracts were included. Participants of the studies must all have received a blood transfusion. Reviews and case studies were excluded. RESULTS: We identified 427 articles or abstracts to include for review. More than half were abstracts, and the majority were published after 2010. Reported TRALI definitions varied, but only 27.2% of studies reported any definition for TRALI. TRALI rates were reported using different denominators, such as per blood unit (54.1%), patient (34.4%), and transfusion episode (14.8%). Study populations and contexts were mostly general (75.6% and 80.3%, respectively). There was also variation in study design with most being observational (90.6%) and only 13.1% of all studies used modern donor restriction policies. DISCUSSION: There was substantial variation in reporting in studies on TRALI incidence. Meta-analysis of TRALI rates may be feasible in specific circumstances where reporting is clear. Future studies should clearly report key items, such as a TRALI definition.
Assuntos
Lesão Pulmonar Aguda Relacionada à Transfusão , Humanos , Transfusão de Sangue , Lesão Pulmonar Aguda Relacionada à Transfusão/epidemiologia , Metanálise como AssuntoRESUMO
BACKGROUND: The relative safety of bacterial risk control strategies for platelets that include culture with or without rapid testing has been compared using simulation analysis. A wide range of bacterial lag and doubling times were included. However, published data on growth rates are available and these data have not been synthesized. We conducted a systematic review and meta-analysis to estimate growth rates and used these estimates to refine a comparative safety analysis of bacterial risk control strategies in the FDA guidance STUDY DESIGN AND METHODS: Data were extracted from published studies on bacterial growth rates in platelet components during storage. These data were used to estimate the practical range of growth rates. This refined the inputs for a simulation model comparing the safety of the testing strategies. RESULTS: In total, 108 growth curves for 11 different aerobic organisms were obtained. Doubling times ranged from 0.8 to 12 h, but the lower 90% range was approximately 1-5 h. The revised comparative safety simulation using the narrower 1-5-h range showed similar rankings to the prior simulation, with 48-h large-volume delayed sampling with 7-day expiration (48C-7) demonstrating the lowest-ranking relative performance at the 103 and 105 colony forming unit (CFU)/mL exposure thresholds. DISCUSSION: This was a two-step study. First, meta-analysis of published data on aerobic bacterial growth rates in stored platelets showed the vast majority of doubling times were 1-5 h. Next, an updated comparative safety simulation yielded similar results to a prior study, with 48C-7 showing the least favorable relative safety performance.
Assuntos
Plaquetas , Comportamentos Relacionados com a Saúde , Humanos , Simulação por ComputadorRESUMO
BACKGROUND: Non-pathogen reduction platelet bacterial risk control strategies in the US FDA guidance include at least one culture. Almost all of these strategies have a culture hold time of ≥12 h. Studies have reported time to detection (TTD) of bacterial cultures inoculated with bacteria from contaminated platelets, but these data and estimates of risk associated with detection failures have not been synthesized. METHODS: We performed a literature search to identify studies reporting TTD for samples obtained from spiked platelet components. Using extracted data, regression analysis was used to estimate TTD for culture bottles at different inoculum sizes. Detection failures were defined as events in which contaminated components are transfused to a patient. We then used published data on time of transfusion (ToT) to estimate the risk of detection failures in practice. RESULTS: The search identified 1427 studies, of which 16 were included for analysis. TTD data were available for 16 different organisms, including 14 in aerobic cultures and 11 in anaerobic cultures. For inocula of 1 colony forming unit (CFU), the average TTD for aerobic organisms was 19.2 h while it was 24.9 h in anaerobic organisms, but there was substantial overall variation. A hold time of 12 versus 24 h had minimal effect for most organisms. CONCLUSION: TTD variation occurs between bacterial species and within a particular species. Under typical inventory management, the relative contribution of culture detection failures is much smaller than the residual risk from sampling failures. Increasing the hold period beyond 12 h has limited value.
Assuntos
Bactérias , Plaquetas , Humanos , Plaquetas/microbiologia , Fatores de Tempo , Transfusão de PlaquetasRESUMO
OBJECTIVES: There is continuing pressure to improve the cost effectiveness of quality control (QC) for clinical laboratory testing. Risk-based approaches are promising but recent research has uncovered problems in some common methods. There is a need for improvements in risk-based methods for quality control. METHODS: We provide an overview of a dynamic model for assay behavior. We demonstrate the practical application of the model using simulation and compare the performance of simple Shewhart QC monitoring against Westgard rules. We also demonstrate the utility of trade-off curves for analysis of QC performance. RESULTS: Westgard rules outperform simple Shewhart control over a narrow range of the trade-off curve of false-positive and false negative risk. The risk trade-off can be visualized in terms of risk, risk vs. cost, or in terms of cost. Risk trade-off curves can be "smoothed" by log transformation. CONCLUSIONS: Dynamic risk-models may provide advantages relative to static models for risk-based QC analysis.
Assuntos
Técnicas de Laboratório Clínico , Humanos , Controle de Qualidade , Simulação por Computador , Medição de RiscoRESUMO
BACKGROUND AND OBJECTIVES: Septic transfusion reactions are a principal cause of transfusion-related mortality. The frequency of detectable bacterial contamination is greater in platelets compared to other blood components because platelets are stored at room temperature. Most strategies outlined in the September 2019 FDA guidance require both aerobic culture (AC) and anaerobic culture (AnC) testing. We performed a systematic review and meta-analysis in an effort to provide the best available estimate of the effectiveness of AnC. MATERIALS AND METHODS: Our analysis was performed according to published guidelines. Broad and context-specific meta-analyses of bacterial detection rates in platelets by AnC were performed to assess the practical effectiveness of AnC as a risk control measure. RESULTS: Seven studies with a total of 1 767 014 tested platelet components were included for analysis. With exclusion of positives due to Cutibacterium/Propionibacterium species and redundancy due to AC results, AnC detected 0·06 contamination events per thousand (EPT) components tested, twofold lower than the AC (0·12 EPT). CONCLUSION: Excluding Cutibacterium/Propionibacterium species, AnC detects occasional bacterial contamination events that are not detected by AC (~1 in 17 000 platelet components).
Assuntos
Bactérias/metabolismo , Técnicas Bacteriológicas/métodos , Plaquetas/microbiologia , Contaminação de Medicamentos/prevenção & controle , Transfusão de Plaquetas/métodos , Reação Transfusional/microbiologia , Anaerobiose , Segurança do Sangue , Humanos , Transfusão de Plaquetas/efeitos adversos , Reação Transfusional/prevenção & controleRESUMO
BACKGROUND: Platelets have the highest bacterial contamination risk of all blood components, and septic transfusion reactions remain a problem. A good estimate of contamination rates could provide information about residual risk and inform optimal testing strategies. We performed a systematic review and meta-analysis of platelet contamination rates by primary culture. STUDY DESIGN AND METHODS: A literature search in December 2019 identified articles on platelet contamination rates using primary culture. We used meta-analysis to estimate the overall rate of contamination and meta-regression to identify heterogeneity. We studied the following sources of heterogeneity: collection method, sample volume, positivity criteria, and study date. Contamination rate estimates were obtained for apheresis (AP), platelet rich plasma (PRP), and buffy coat (BC) collection methods. RESULTS: The search identified 6102 studies, and 22 were included for meta-analysis. Among these 22 studies, there were 21 AP cohorts (4,072,022 components), 4 PRP cohorts (138,869 components), and 15 BC cohorts (1,474,679 components). The overall mean contamination rate per 1000 components was 0.51 (95% CI: 0.38-0.67) including AP (0.23, 95% CI: 0.18-0.28), PRP, (0.38, 95% CI: 0.15-0.70), and BC (1.12, 95% CI: 0.51-1.96). There was considerable variability within each collection method. Sample volume, positivity criteria, and publication year were significant sources of heterogeneity. CONCLUSION: The bacterial contamination rate of platelets by primary culture is 1 in 1961. AP and PRP components showed a lower contamination rate than BC components. There is clinically significant between-study variability for each method. Larger sample volumes increased sensitivity, and bacterial contamination rates have decreased over time.
Assuntos
Infecções Bacterianas/sangue , Remoção de Componentes Sanguíneos/estatística & dados numéricos , Plaquetas/microbiologia , Contaminação de Medicamentos/estatística & dados numéricos , Transfusão de Plaquetas/estatística & dados numéricos , Cultura Primária de Células/estatística & dados numéricos , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/transmissão , Técnicas Bacteriológicas , Remoção de Componentes Sanguíneos/efeitos adversos , Transfusão de Componentes Sanguíneos/efeitos adversos , Transfusão de Componentes Sanguíneos/estatística & dados numéricos , Plaquetas/citologia , Células Cultivadas , Humanos , Transfusão de Plaquetas/efeitos adversos , Plasma Rico em Plaquetas/microbiologia , Cultura Primária de Células/métodos , Cultura Primária de Células/normas , Reação Transfusional/epidemiologia , Reação Transfusional/microbiologiaRESUMO
BACKGROUND: Primary culture alone was a bacterial risk control strategy intended to facilitate interdiction of contaminated platelets (PLTs). A September 2019 FDA guidance includes secondary testing options to enhance safety. Our objective was to use meta-analysis to determine residual contamination risk after primary culture using secondary culture and rapid testing. STUDY DESIGN AND METHODS: A December 2019 literature search identified articles on PLT bacterial detection rates using primary culture and a secondary testing method. We used meta-analysis to estimate secondary testing detection rates after a negative primary culture. We evaluated collection method, sample volume, sample time, and study date as potential sources of heterogeneity. RESULTS: The search identified 6102 articles; 16 were included for meta-analysis. Of these, 12 used culture and five used rapid testing as a secondary testing method. Meta-analysis was based on a total of 103 968 components tested by secondary culture and 114 697 by rapid testing. The residual detection rate using secondary culture (DRSC ) was 0.93 (95% CI, 0.24-0.6) per 1000 components, while residual detection rate using rapid testing (DRRT ) was 0.09 (95% CI, 0.01-0.25) per 1000 components. Primary culture detection rate was the only statistically significant source of heterogeneity. CONCLUSION: We evaluated bacterial detection rates after primary culture using rapid testing and secondary culture. These results provide a lower and upper bound on real-world residual clinical risk because these methods are designed to detect high-level exposures or any level of exposure, respectively. Rapid testing may miss some harmful exposures and secondary culture may identify some clinically insignificant exposures.
Assuntos
Bactérias/crescimento & desenvolvimento , Técnicas Bacteriológicas , Hemocultura , Plaquetas/microbiologia , Transfusão de Plaquetas/efeitos adversos , Sepse , Reação Transfusional , Bactérias/classificação , Feminino , Humanos , Masculino , Sepse/etiologia , Sepse/microbiologia , Reação Transfusional/etiologia , Reação Transfusional/microbiologiaRESUMO
BACKGROUND: Bacterial contamination of platelets is a problem that can lead to harmful septic transfusion reactions. The US Food and Drug Administration published a guidance in September 2019 detailing several permissible risk control strategies. Our objective was to compare the safety of each bacterial testing strategy for apheresis platelets. STUDY DESIGN AND METHODS: We used simulation to compare safety of the nine risk control strategies involving apheresis platelet testing. The primary outcome was the risk of exposure. An exposure event occurred if a patient received platelets exceeding a specific contamination threshold (>0, 103 , and 105 colony-forming units (CFU/mL). We generated a range of bacterial contamination scenarios (inoculum size, doubling time, lag time) and compared risk of exposure for each policy in each contamination scenario. We then computed the average risk difference over all scenarios. RESULTS: At the 0 CFU/mL exposure threshold, two-step policies that used secondary culture ranked best (all top three), while single-step 24-hour culture with 3-day expiration ranked last (ninth). This latter policy performed well (median rank of 1) at both the 103 and 105 CFU/mL thresholds, but 48-hour culture with 7-day expiration performed relatively poorly. At these higher thresholds, median ranks of two-step policies that used secondary culture were again top three. Two-step policies that used rapid testing improved at the higher (105 CFU/mL) harm threshold, with median rankings between 1 and 5. CONCLUSION: Two-step policies that used secondary culture were generally safer than single-step policies. Performance of two-step policies that used rapid testing depended on the CFU per milliter threshold of exposure used.
Assuntos
Infecções Bacterianas , Plaquetas/microbiologia , Segurança do Sangue , Modelos Biológicos , Transfusão de Plaquetas , Plaquetoferese , Infecções Bacterianas/sangue , Infecções Bacterianas/etiologia , Política de Saúde , Humanos , Fatores de RiscoRESUMO
BACKGROUND: Invasive fungal infections (IFIs) are life-threatening opportunistic infections that occur in immunocompromised or critically ill people. Early detection and treatment of IFIs is essential to reduce morbidity and mortality in these populations. (1â3)-ß-D-glucan (BDG) is a component of the fungal cell wall that can be detected in the serum of infected individuals. The serum BDG test is a way to quickly detect these infections and initiate treatment before they become life-threatening. Five different versions of the BDG test are commercially available: Fungitell, Glucatell, Wako, Fungitec-G, and Dynamiker Fungus. OBJECTIVES: To compare the diagnostic accuracy of commercially available tests for serum BDG to detect selected invasive fungal infections (IFIs) among immunocompromised or critically ill people. SEARCH METHODS: We searched MEDLINE (via Ovid) and Embase (via Ovid) up to 26 June 2019. We used SCOPUS to perform a forward and backward citation search of relevant articles. We placed no restriction on language or study design. SELECTION CRITERIA: We included all references published on or after 1995, which is when the first commercial BDG assays became available. We considered published, peer-reviewed studies on the diagnostic test accuracy of BDG for diagnosis of fungal infections in immunocompromised people or people in intensive care that used the European Organization for Research and Treatment of Cancer (EORTC) criteria or equivalent as a reference standard. We considered all study designs (case-control, prospective consecutive cohort, and retrospective cohort studies). We excluded case studies and studies with fewer than ten participants. We also excluded animal and laboratory studies. We excluded meeting abstracts because they provided insufficient information. DATA COLLECTION AND ANALYSIS: We followed the standard procedures outlined in the Cochrane Handbook for Diagnostic Test Accuracy Reviews. Two review authors independently screened studies, extracted data, and performed a quality assessment for each study. For each study, we created a 2 × 2 matrix and calculated sensitivity and specificity, as well as a 95% confidence interval (CI). We evaluated the quality of included studies using the Quality Assessment of Studies of Diagnostic Accuracy-Revised (QUADAS-2). We were unable to perform a meta-analysis due to considerable variation between studies, with the exception of Candida, so we have provided descriptive statistics such as receiver operating characteristics (ROCs) and forest plots by test brand to show variation in study results. MAIN RESULTS: We included in the review 49 studies with a total of 6244 participants. About half of these studies (24/49; 49%) were conducted with people who had cancer or hematologic malignancies. Most studies (36/49; 73%) focused on the Fungitell BDG test. This was followed by Glucatell (5 studies; 10%), Wako (3 studies; 6%), Fungitec-G (3 studies; 6%), and Dynamiker (2 studies; 4%). About three-quarters of studies (79%) utilized either a prospective or a retrospective consecutive study design; the remainder used a case-control design. Based on the manufacturer's recommended cut-off levels for the Fungitell test, sensitivity ranged from 27% to 100%, and specificity from 0% to 100%. For the Glucatell assay, sensitivity ranged from 50% to 92%, and specificity ranged from 41% to 94%. Limited studies have used the Dynamiker, Wako, and Fungitec-G assays, but individual sensitivities and specificities ranged from 50% to 88%, and from 60% to 100%, respectively. Results show considerable differences between studies, even by manufacturer, which prevented a formal meta-analysis. Most studies (32/49; 65%) had no reported high risk of bias in any of the QUADAS-2 domains. The QUADAS-2 domains that had higher risk of bias included participant selection and flow and timing. AUTHORS' CONCLUSIONS: We noted considerable heterogeneity between studies, and these differences precluded a formal meta-analysis. Because of wide variation in the results, it is not possible to estimate the diagnostic accuracy of the BDG test in specific settings. Future studies estimating the accuracy of BDG tests should be linked to the way the test is used in clinical practice and should clearly describe the sampling protocol and the relationship of time of testing to time of diagnosis.
Assuntos
Estado Terminal , Hospedeiro Imunocomprometido , Infecções Fúngicas Invasivas/diagnóstico , beta-Glucanas/sangue , Aspergilose/diagnóstico , Biomarcadores/sangue , Candidíase Invasiva/diagnóstico , Estudos de Casos e Controles , Humanos , Infecções por Pneumocystis/diagnóstico , Pneumocystis carinii , Estudos Prospectivos , Curva ROC , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Invasive fungal infection (IFI) is a life-threatening complication of allogeneic hematopoietic stem cell transplantation (HSCT) that is also associated with excess healthcare costs. Current approaches include universal antifungal prophylaxis, preemptive therapy based on biomarker surveillance, and empiric treatment initiated in response to clinical signs/symptoms. However, no study has directly compared the cost-effectiveness of these treatment strategies for an allogeneic HSCT patient population. METHODS: We developed a state transition model to study the impact of treatment strategies on outcomes associated with IFIs in the first 100 days following myeloablative allogeneic HSCT. We compared three treatment strategies: empiric voriconazole, preemptive voriconazole (200 mg), or prophylactic posaconazole (300 mg) for the management of IFIs. Preemptive treatment was guided by scheduled laboratory surveillance with galactomannan (GM) testing. Endpoints were cost and survival at 100 days post-HSCT. RESULTS: Empiric treatment was the least costly ($147 482) and was equally effective (85.2% survival at 100 days) as the preemptive treatment strategies. Preemptive treatments were slightly more costly than empiric treatment (GM cutoff ≥ 1.0 $147 910 and GM cutoff ≥ 0.5 $148 108). Preemptive therapy with GM cutoff ≥ 1.0 reduced anti-mold therapy by 5% when compared to empiric therapy. Posaconazole prophylaxis was the most effective (86.6% survival at 100 days) and costly ($152 240) treatment strategy with a cost of $352 415 per life saved when compared to empiric therapy. CONCLUSIONS: One preemptive treatment strategy reduced overall anti-mold drug exposure but did not reduce overall costs. Prevention of IFI using posaconazole prophylaxis was the most effective treatment strategy and may be cost-effective, depending upon the willingness to pay per life saved.
Assuntos
Antifúngicos/administração & dosagem , Antifúngicos/economia , Análise Custo-Benefício , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Infecções Fúngicas Invasivas/prevenção & controle , Condicionamento Pré-Transplante , Humanos , Infecções Fúngicas Invasivas/economia , Modelos Biológicos , Transplante Homólogo/efeitos adversos , Resultado do TratamentoRESUMO
OBJECTIVE: The aim of this article is to determine the cost effectiveness of cell free DNA (cfDNA) as a replacement for integrated screening using a societal cost perspective. METHOD: This study used Monte-Carlo simulation with one-way and probabilistic sensitivity analysis. RESULTS: Cell free DNA is more effective and less costly than integrated screening. The incremental cost-effectiveness ratio for cfDNA relative to the integrated test was -$277 955 per case detected (95th percent confidence interval -$881 882 to $532 785). CONCLUSION: Cell free DNA screening is a cost-effective replacement for maternal serum screening when the lifetime costs of Down syndrome live births are considered. The adoption of cfDNA screening would save approximately $277 955 for each additional case detected over integrated screening.
Assuntos
Aborto Induzido/economia , DNA/sangue , Síndrome de Down/economia , Diagnóstico Pré-Natal/economia , Análise Custo-Benefício , Síndrome de Down/sangue , Síndrome de Down/diagnóstico , Feminino , Humanos , Método de Monte Carlo , GravidezRESUMO
BACKGROUND: The effectiveness of endoscopic ultrasound-guided fine-needle aspiration increases with the number of needle passes but needle passes are also associated with increased risk of adverse events. The trade-off between needle passes and adequacy has not been well-characterized. AIMS: The purpose of this study was to compare the risk-benefit tradeoff of different sampling protocols with and without rapid onsite evaluation (ROSE). PATIENTS AND METHODS: We used a discrete-event simulation model to compare eight different sampling protocols. Each sampling protocol was simulated 10,000 times to obtain the average performance for each scenario. The per-pass adequacy rates, ROSE, accuracy of the assessor and sampling limits were varied to determine the impact of these factors on the number of needle passes and adequacy rates. RESULTS: Increasing per-class adequacy can be achieved at a cost of increased needle passes. Sampling with ROSE achieved higher adequacy with fewer needle passes than policies using a fixed number of needle passes without ROSE. CONCLUSIONS: Variable sampling policies using ROSE generally achieve greater per-case adequacy with fewer needle passes than non-ROSE sampling policies using a fixed number of passes.
Assuntos
Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico/métodos , Neoplasias Pancreáticas/patologia , Teorema de Bayes , Humanos , Neoplasias Pancreáticas/diagnóstico , Sensibilidade e EspecificidadeRESUMO
OBJECTIVE: To examine the effects of Hispanic nativity on the risk and severity of hypertension relative to US-born non-Hispanic whites. METHODS: The analytic sample (n = 34,007) was comprised of cross-sectional data drawn from twenty years of the National Health and Nutrition Examination Survey, 1999-2018. RESULTS: Foreign-born Hispanics aged 65 years and older had a greater risk of severe hypertension compared to non-Hispanic Whites. When examined by length of residency in the US, elderly foreign-born Hispanics with less than 10 years of residency were at greater risk of hypertension and severe hypertension, while those with 20 or more years of residency had similar risks compared to non-Hispanic Whites. CONCLUSION: The "Hispanic Paradox" of better health despite lower socioeconomic status, was not observed in foreign-born or US-born Hispanics aged 65 years and older. Among elderly immigrants, those with fewer years of residency had the greatest hypertensive risk.
Assuntos
Hispânico ou Latino , Hipertensão , Idoso , Humanos , Estados Unidos/epidemiologia , Inquéritos Nutricionais , Estudos Transversais , Análise MultivariadaRESUMO
BACKGROUND: The dynamic Precision QC (PQC) model can be used to evaluate the performance of quality control (QC) monitoring systems. The model depends on inputs that describe the intrinsic shift behavior (i.e., stability) of an assay. The output of the model is a trade-off curve that shows the relationship between false negative (FN) and false positive (FP) risk events. The relationship between the inputs and outputs of this model has not yet been explored. METHODS: We used Monte Carlo simulation to generate trade-off curves using the PQC. We varied the input parameters that determine assay stability (shift probability and shift size distribution) and studied the impact of these inputs on the output (i.e., the trade-off curve relating FN risk to FP risk). RESULTS: FN risk is sensitive to the shift probability and the width of the control limits. FN risk is sensitive to the shape of the shift size distribution when the standard deviation (SD) of the shift size distribution is relatively narrow (i.e., SD < 2) but is less sensitive to the width of the shift size distribution when the SD is relatively large (i.e., SD > 2). CONCLUSIONS: Practical use of the PQC model may require the estimation of the shift probability and shift size distribution.
Assuntos
Bioensaio , Humanos , Controle de QualidadeRESUMO
BACKGROUND: We developed a theoretical framework (Precision Quality Control [PQC]) to minimize the cost of quality, but it is not known whether the method can be applied in practice. METHODS: We used data for 2 analytes, cadmium and carbohydrate-deficient transferrin (CDT), and applied the PQC framework to find the optimal control limits. These analytes were selected because they differed with respect to sigma values that are major determinants of control limits. We explored different ways to visualize the results: (a) risk trade-off (false-positive risk vs false-negative risk), (b) cost-risk trade-off (false-positive cost vs false-negative risk), and (c) cost minimization. RESULTS: We were able to use the PQC limit to produce 3 different visualizations to suggest control limits. The risk-based analysis was the simplest to apply, but the most difficult to interpret. The cost vs risk method was easy to apply but was still difficult to interpret. The cost minimization method was easy to interpret but required users to declare a willingness to pay that may be difficult to estimate. CONCLUSIONS: The PQC method can be used to find control limits that minimize the cost of quality.
RESUMO
BACKGROUND: Setting quality control (QC) limits involves balancing the risk of false-positive results and false-negative results. Recent approaches to QC have focused on the assessment of false-negative results. The Parvin model is the most-used model for risk analysis. The Parvin model assumes that the system makes a transition from an in-control to an out-of-control (OOC) state but makes no further transitions after moving to the OOC state. The implications of this assumption are unclear. METHODS: We used simulation experiments to compare the performance of QC systems based on no OOC transitions allowed (NOOCTA) vs systems where OOC transitions were allowed (OOCTA). RESULTS: The NOOCTA assumption leads to paradoxical tradeoff curves between false-positive results and false-negative results. Predictions of a false-negative result based on NOOCTA were about 10 times lower than models based on OOCTA. CONCLUSIONS: The most common models for QC risk analysis underestimate false-negative results. There is a need to develop better risk-based methods for QC analysis.
Assuntos
Controle de Qualidade , Humanos , Medição de RiscoRESUMO
OBJECTIVE: To determine the impact of myeloperoxidase (MPO) and proteinase 3 (PR3) antigen-specific immunoassays in the stratification of patients at-risk for anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitides (AAV) at diagnosis. METHODS: A Medline search was conducted to identify diagnostic accuracy studies using PR3-ANCA or MPO-ANCA for the evaluation of granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). Studies estimates were pooled using the bivariate method. RESULTS: Diagnostic accuracy varied by analyte and AAV subtype. PR3-ANCA had greater sensitivity than MPO-ANCA for GPA (74% vs 11%, p < 0.001) and MPO-ANCA greater sensitivity for MPA (73% vs 7%, p < 0.001). Specificities of both MPO-ANCA and PR3-ANCA were consistently high (mean 97%, range: 93-99%) for both AAV subtypes. There was insufficient data to perform meta-analysis for the diagnostic accuracy of EPGA. CONCLUSION: These results validate the use of high quality MPO-ANCA and PR3-ANCA immunoassays to screen patients at-risk for AAV as well as to categorize disease as GPA or MPA subtype. However, caution must be exercised in doing so, since some assays may not have optimal performance. Each laboratory should validate appropriate algorithms based on the tests used and testing population.
Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos , Síndrome de Churg-Strauss , Granulomatose com Poliangiite , Poliangiite Microscópica , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/diagnóstico , Anticorpos Anticitoplasma de Neutrófilos , Síndrome de Churg-Strauss/diagnóstico , Granulomatose com Poliangiite/diagnóstico , Humanos , Imunoensaio , Mieloblastina , PeroxidaseRESUMO
Septic reactions from platelet transfusions are one of the leading causes of transfusion-associated mortality. The FDA guidance for platelet bacterial risk control includes bacterial culture using both aerobic and anaerobic bottles. Several studies have reported false positive rates (FPR) of culture, but these data have not been summarized or influencing factors analyzed. A systematic review and meta-analysis was performed according to published guidelines to assess the false positive rate and influencing factors. Eighteen studies were included for analysis. The combined aerobic/anaerobic FPR was 2.4 events per thousand (EPT) with a prediction interval of 0.5 to 5.7, while the aerobic FPR rate was 1.0 EPT (prediction interval: 0.2-2.2) and the anaerobic rate was 1.8 EPT. Estimates were based on a total of almost 5 million units tested. The rate of false positives due to instrument error was between 0.5-1.7 EPT, while it was between 0.3-1.0 EPT for sampling contamination based on whether only aerobic, anaerobic, or aerobic/anaerobic cultures were performed. The FPR is approximately 2 to 5 times higher than the literature reported true positive rate of 0.5 EPT.
Assuntos
Plaquetas , Transfusão de Plaquetas , Anaerobiose , Bactérias , Humanos , Controle de QualidadeRESUMO
BACKGROUND: Multirules are often employed to monitor quality control (QC). The performance of multirules is usually determined by simulation and is difficult to predict. Previous studies have not provided computer code that would enable one to experiment with multirules. It would be helpful for analysts to have computer code to analyze rule performance. OBJECTIVE: To provide code to calculate power curves and to investigate certain properties of multirule QC. METHODS: We developed computer code in the R language to simulate multirule performance. Using simulation, we studied the incremental performance of each rule and determined the average run length and time to signal. RESULTS: We provide R code for simulating multirule performance. We also provide a Microsoft Excel spreadsheet with a tabulation of results that can be used to create power curves. We found that the R4S and 10x rules add very little power to a multirule set designed to detect shifts in the mean. CONCLUSION: QC analysts should consider using a limited-rule set.