RESUMO
Type I error probability spending functions are commonly used for designing sequential analysis of binomial data in clinical trials, but it is also quickly emerging for near-continuous sequential analysis of post-market drug and vaccine safety surveillance. It is well known that, for clinical trials, when the null hypothesis is not rejected, it is still important to minimize the sample size. Unlike in post-market drug and vaccine safety surveillance, that is not important. In post-market safety surveillance, specially when the surveillance involves identification of potential signals, the meaningful statistical performance measure to be minimized is the expected sample size when the null hypothesis is rejected. The present paper shows that, instead of the convex Type I error spending shape conventionally used in clinical trials, a concave shape is more indicated for post-market drug and vaccine safety surveillance. This is shown for both, continuous and group sequential analysis.
Assuntos
Sistemas de Notificação de Reações Adversas a Medicamentos/estatística & dados numéricos , Vigilância de Produtos Comercializados/estatística & dados numéricos , Vacinas/efeitos adversos , Sistemas de Notificação de Reações Adversas a Medicamentos/economia , Bioestatística , Interpretação Estatística de Dados , Humanos , Modelos Estatísticos , Probabilidade , Vigilância de Produtos Comercializados/economiaRESUMO
OBJECTIVE: To describe different approaches to promote adverse drug reaction reporting among health care professionals, determining their cost-effectiveness. METHODS: We analyzed and compared several approaches taken by the Northern Pharmacovigilance Centre (Portugal) to promote adverse drug reaction reporting. Approaches were compared regarding the number and relevance of adverse drug reaction reports obtained and costs involved. Costs by report were estimated by adding the initial costs and the running costs of each intervention. These costs were divided by the number of reports obtained with each intervention, to assess its cost-effectiveness. RESULTS: All the approaches seem to have increased the number of adverse drug reaction reports. We noted the biggest increase with protocols (321 reports, costing 1.96 each), followed by first educational approach (265 reports, 20.31 /report) and by the hyperlink approach (136 reports, 15.59 /report). Regarding the severity of adverse drug reactions, protocols were the most efficient approach, costing 2.29 /report, followed by hyperlinks (30.28 /report, having no running costs). Concerning unexpected adverse drug reactions, the best result was obtained with protocols (5.12 /report), followed by first educational approach (38.79 /report). CONCLUSIONS: We recommend implementing protocols in other pharmacovigilance centers. They seem to be the most efficient intervention, allowing receiving adverse drug reactions reports at lower costs. The increase applied not only to the total number of reports, but also to the severity, unexpectedness and high degree of causality attributed to the adverse drug reactions. Still, hyperlinks have the advantage of not involving running costs, showing the second best performance in cost per adverse drug reactions report.
Assuntos
Sistemas de Notificação de Reações Adversas a Medicamentos/economia , Sistemas de Notificação de Reações Adversas a Medicamentos/instrumentação , Monitoramento de Medicamentos/métodos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Análise Custo-Benefício , Pessoal de Saúde , Humanos , Farmacovigilância , PortugalRESUMO
ABSTRACT OBJECTIVE To describe different approaches to promote adverse drug reaction reporting among health care professionals, determining their cost-effectiveness. METHODS We analyzed and compared several approaches taken by the Northern Pharmacovigilance Centre (Portugal) to promote adverse drug reaction reporting. Approaches were compared regarding the number and relevance of adverse drug reaction reports obtained and costs involved. Costs by report were estimated by adding the initial costs and the running costs of each intervention. These costs were divided by the number of reports obtained with each intervention, to assess its cost-effectiveness. RESULTS All the approaches seem to have increased the number of adverse drug reaction reports. We noted the biggest increase with protocols (321 reports, costing 1.96 € each), followed by first educational approach (265 reports, 20.31 €/report) and by the hyperlink approach (136 reports, 15.59 €/report). Regarding the severity of adverse drug reactions, protocols were the most efficient approach, costing 2.29 €/report, followed by hyperlinks (30.28 €/report, having no running costs). Concerning unexpected adverse drug reactions, the best result was obtained with protocols (5.12 €/report), followed by first educational approach (38.79 €/report). CONCLUSIONS We recommend implementing protocols in other pharmacovigilance centers. They seem to be the most efficient intervention, allowing receiving adverse drug reactions reports at lower costs. The increase applied not only to the total number of reports, but also to the severity, unexpectedness and high degree of causality attributed to the adverse drug reactions. Still, hyperlinks have the advantage of not involving running costs, showing the second best performance in cost per adverse drug reactions report.
RESUMO OBJETIVO Descrever diferentes abordagens de promoção da notificação de reações adversas a medicamentos entre os profissionais de saúde, determinando o seu custo-eficácia. MÉTODOS Foram analisadas e comparadas estratégias adotadas pela Unidade de Farmacovigilância do Norte (Portugal) para promoção da notificação de reações adversas a medicamentos. As estratégias foram comparadas quanto ao número e relevância das notificações de reações adversas a medicamentos obtidas e quanto aos custos envolvidos. Os custos por notificação foram calculados somando os custos iniciais e os custos de manutenção de cada estratégia. Esses custos foram então divididos pelo número de notificações obtidas em cada intervenção, para avaliar o seu custo-eficácia. RESULTADOS Todas as abordagens aumentaram o número de notificações de reações adversas a medicamentos. O maior aumento foi observado com os protocolos (321 notificações de reações adversas a medicamentos ganhas, custando 1,96 € cada), seguidos pela primeira abordagem educacional (265 notificações, 20,31 € cada) e pela colocação de hyperlinks (136 notificações, 15,59 € cada). Com relação à gravidade das reações adversas a medicamentos, os protocolos foram a estratégia mais eficiente, custando 2,29 € cada notificação, seguida da colocação de hyperlinks (30,28 € cada, sem custos de manutenção). Quanto às reações adversas a medicamentos inesperadas, o melhor resultado pertenceu aos protocolos (5,12 € cada notificação), seguido por uma primeira abordagem educativa (38,79 € cada notificação). CONCLUSÕES Os autores recomendam a implementação de protocolos em outros centros de farmacovigilância. De fato, estes parecem ser a intervenção mais eficaz, permitindo receber notificações de RAM com custos mais baixos, aplicando-se este aumento tanto ao número total de notificações de reações adversas a medicamentos, como à gravidade, imprevisibilidade e alto grau de causalidade atribuído a elas. Ainda assim, a colocação de hyperlinks apresenta a vantagem de não envolver custos de manutenção, por isso tem o segundo melhor desempenho no indicador custo por notificação de reações adversas a medicamentos.
Assuntos
Humanos , Monitoramento de Medicamentos/métodos , Sistemas de Notificação de Reações Adversas a Medicamentos/economia , Sistemas de Notificação de Reações Adversas a Medicamentos/instrumentação , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Portugal , Análise Custo-Benefício , Pessoal de Saúde , FarmacovigilânciaRESUMO
ABSTRACT OBJECTIVE To evaluate the association between recurrent wheezing and atopy, the Asthma Predictive Index, exposure to risk factors, and total serum IgE levels as potential factors to predict recurrent wheezing. METHODS A case-control study with infants aged 6-24 months treated at a specialized outpatient clinic from November 2011 to March 2013. Evaluations included sensitivity to inhalant and food antigens, positive Asthma Predictive Index, and other risk factors for recurrent wheezing (smoking during pregnancy, presence of indoor smoke, viral infections, and total serum IgE levels). RESULTS We evaluated 113 children: 65 infants with recurrent wheezing (63.0% male) with a mean age of 14.8 (SD = 5.2) months and 48 healthy infants (44.0% male) with a mean age of 15.2 (SD = 5.1) months. In the multiple analysis model, antigen sensitivity (OR = 12.45; 95%CI 1.28-19.11), positive Asthma Predictive Index (OR = 5.57; 95%CI 2.23-7.96), and exposure to environmental smoke (OR = 2.63; 95%CI 1.09-6.30) remained as risk factors for wheezing. Eosinophilia ≥ 4.0% e total IgE ≥ 100 UI/mL were more prevalent in the wheezing group, but failed to remain in the model. Smoking during pregnancy was identified in a small number of mothers, and secondhand smoke at home was higher in the control group. CONCLUSIONS Presence of atopy, positive Asthma Predictive Index and exposure to environmental smoke are associated to recurrent wheezing. Identifying these factors enables the adoption of preventive measures, especially for children susceptible to persistent wheezing and future asthma onset.
RESUMO OBJETIVO Avaliar a associação entre a sibilância recorrente e atopia, o Índice Preditivo para Asma, exposição a fatores de risco e dosagem de IgE sérica total como possíveis fatores preditores de sibilância recorrente. MÉTODOS Estudo caso-controle com crianças de seis a 24 meses de idade atendidas em ambulatório especializado entre novembro de 2011 e março de 2013. Foram avaliados a sensibilização a antígenos inaláveis e alimentares, positividade para o Índice Preditivo para Asma e outros fatores de risco para sibilância recorrente (tabagismo durante a gravidez, presença de fumaça na residência, infecções virais e dosagem de IgE total). RESULTADOS Foram avaliadas 113 crianças, sendo 65 lactentes sibilantes recorrentes (63,0% do sexo masculino) com média de idade de 14,8 (DP = 5,2) meses e 48 lactentes saudáveis (44,0% do sexo masculino) com média de idade de 15,2 (DP = 5,1) meses. No modelo de análise múltipla, a sensibilização a antígenos (OR = 12,45; IC95% 1,28-19,11), Índice Preditivo para Asma positivo (OR = 5,57; IC95% 2,23-7,96) e exposição à fumaça ambiental (OR = 2,63; IC95% 1,09-6,30) permaneceram como fatores de risco para sibilância. Eosinofilia ≥ 4,0% e IgE total ≥ 100 UI/mL foram mais prevalentes no grupo sibilante, mas não permaneceram no modelo. O tabagismo na gestação foi identificado em pequeno número de mães e o tabagismo domiciliar foi maior no grupo controle. CONCLUSÕES A presença de atopia, a positividade ao Índice Preditivo para Asma e a exposição à fumaça ambiental estão associadas à sibilância recorrente. A identificação desses fatores permite a adoção de medidas preventivas, especialmente nas crianças susceptíveis à persistência de sibilância e ao surgimento de asma no futuro.
Assuntos
Humanos , Monitoramento de Medicamentos/métodos , Sistemas de Notificação de Reações Adversas a Medicamentos/economia , Sistemas de Notificação de Reações Adversas a Medicamentos/instrumentação , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Portugal , Análise Custo-Benefício , Pessoal de Saúde , FarmacovigilânciaRESUMO
To determine the frequency and the direct costs of adverse drug reactions, in an ambulatory population of the City of Buenos Aires, Argentina and its area of influence. A retrospective study was done during a period of three months on approximately 300.000 residents of the Buenos Aires area, gathering data according to the selected variables by means of the electronic capture of prescriptions dispensed in pharmacies of the area. This method enables the detection and registration of potential conflicts that may arise between a prescribed drug and factors such as: patient's demographic, clinical and drug profile. The analysis unit was defined as the happening of a moderate or severe adverse event reported by the system. The selected variables were the incidence of these effects and the direct cost was calculated as the value of the drugs that induced the adverse event. The events were classified according to the following interactions: a) drug-drug, b) drug-pediatrics, c) drug-gender, d) drug-pregnancy and abuse of controlled substances. The observed frequency shows great variability and the shortage of available data for ambulatory populations. We found 6.74% of reported events over the total of processed items, which generated an additional cost equivalent to 4.58% of the total pharmaceutical expenses. This study has only evaluated the cost occurred by the use of a drug that will lead to an adverse reaction. Moderate and severe reactions were included regardless of the important indirect costs, hospitalization costs, tests, physician fees, etc.