Methods to evaluate COVID-19 vaccine effectiveness, with an emphasis on quasi-experimental approaches. / Métodos para avaliação da efetividade de vacinas para COVID-19 com ênfase em abordagens quase-experimentais.

The evaluation of vaccine effectiveness is conducted with real-world data. They are essential to monitor the performance of vaccination programmes over time, and in the context of the emergence of new variants. Until now, the effectiveness of COVID-19 vaccines has been assessed based on classic methods, such as cohort and test-negative case-control studies, which may often not allow for adequate control of inherent biases in the assignment of vaccination campaigns. The aim of this review was to discuss the study designs available to evaluate vaccine effectiveness, highlighting quasi-experimental studies, which seek to mimic randomized trials, by introducing an exogenous component to allocate to treatment, in addition to the advantages, limitations, and applicability in the context of Brazilian data. The use of quasi-experimental approaches, such as interrupted time series, difference-in-differences, propensity scores, instrumental variables, and regression discontinuity design, are relevant due to the possibility of providing more accurate estimates of COVID-19 vaccine effectiveness. This is especially important in scenarios such as the Brazilian, which characterized by the use of various vaccines, with the respective numbers and intervals between doses, applied to different age groups, and introduced at different times during the pandemic.

A avalição da efetividade de vacinas é feita com dados do mundo real e é essencial para monitorar o desempenho dos programas de vacinação ao longo do tempo bem como frente a novas variantes. Até o momento, a avaliação da efetividade das vacinas para COVID-19 tem sido baseada em métodos clássicos como estudos de coorte e caso controle teste-negativo, que muitas vezes podem não permitir o adequado controle dos vieses intrínsecos da alocação das campanhas de vacinação. O objetivo dessa revisão foi discutir os desenhos de estudo disponíveis para avaliação de efetividade das vacinas, enfatizando os estudos quase-experimentais, que buscam mimetizar os estudos aleatorizados ao introduzir um componente exógeno para atribuição ao tratamento, bem como suas vantagens, limitações e aplicabilidade no contexto dos dados brasileiros. O emprego de métodos quase-experimentais, incluindo as séries temporais interrompidas, o método de diferença em diferenças, escore de propensão, variáveis instrumentais e regressão descontínua, são relevantes pela possibilidade de gerar estimativas mais acuradas da efetividade de vacinas para COVID-19 em cenários como o brasileiro, que se caracteriza pelo uso de várias vacinas, com respectivos número e intervalos entre doses, aplicadas em diferentes faixas etárias e em diferentes momentos da pandemia.

Impact of the COVID-19 pandemic on the mental health of frontline healthcare workers in a highly affected region in Brazil.

BACKGROUND: The COVID-19 pandemic had a major impact on the mental health of healthcare workers (HCWs), especially in low and middle-income countries, which had to face additional political, social, and economic challenges. We thus aimed to assess the prevalence of mental health outcomes and the associated factors in HCWs treating COVID-19 patients in one of the most affected regions in Brazil. METHODS: We used the Respondent-Driven Sampling method to assess the risks of COVID-19 infection and symptoms of mental disorders in nurses, nursing technicians, and physicians who worked on the frontline in the metropolitan region of Recife. 865 healthcare workers completed a survey regarding sociodemographic data, work-related risks, and symptoms of mental disorders - SRQ-20 for common mental disorders (CMD); AUDIT-C for problematic alcohol use; GAD-7 for anxiety; PHQ-9 for depression; PCL-5 for post-traumatic stress disorder (PTSD). Gile's successive sampling estimator was used to produce the weighted estimates by professional category. A Poisson regression model with robust variance was used to analyze factors associated with a positive screening for CMD. We will present the results of a cross-sectional analysis of the mental health outcomes after the first peak of COVID-19 - from August 2020 to February 2021. RESULTS: The prevalence ratios for a positive screening for CMD were 34.9% (95% CI: 27.8-41.9) in nurses, 28.6% (95% CI: 21.3-36.0) in physicians, and 26.6% (95% CI: 16.8-36.5) in nursing technicians. Nurses presented a higher prevalence of depressive symptoms (23%). Positive screening for problematic alcohol use (10.5 to14.0%), anxiety (10.4 to 13.3%), and PTSD (3.3 to 4.4%) were similar between the professional categories. The main factors associated with CMD in nurses and physicians were related to an intrinsic susceptibility to mental illness, such as previous or family history of psychiatric disorder, and female sex. Among nurse technicians, work-related factors, such as accidents with biological material, presented the strongest association with CMD. CONCLUSION: The mental health of HCWs fighting COVID-19 in Recife was severely affected. It is crucial that healthcare services provide adequate working conditions and psychological support, investing in programs to promote and protect HCWs mental health.

Reports from the frontline: health workers describe COVID-19 risks and fears in five cities in Brazil.

BACKGROUND: Health providers are under unprecedented pressures to perform in the COVID-19 health crisis and under unprecedented risks. We initiated a large mixed-method survey of health professionals in five large metropolitan areas in Brazil to document the risks and needs of health professionals. To initiate the study, we conducted formative research. METHODS: We conducted 77 open-ended semi-structured interviews online in a convenience sample of physicians, nurses, nurse technicians, and physiotherapists in Belem, Fortaleza, Porto Alegre, Recife, and São Paulo, Brazil. Design, data collection, and analysis were informed by Rapid Ethnographic Analysis (REA). RESULTS: Responses are organized into three themes that emerged in the interviews: the lack of preparation - both locally and nationally-for the pandemic and its effects on staffing and training; the overlap of personal, family, and professional risk and consequences; and inadequately addressed anxiety and suffering among health staff. CONCLUSIONS: Our respondents were unprepared for the epidemic, especially the institutional sequelae and psychological cost. These consequences were exacerbated by both lack of leadership and sweeping changes undercutting the Brazilian health system noted by almost all participants.

Risk of SARS-CoV-2 infection among front-line healthcare workers in Northeast Brazil: a respondent-driven sampling approach.

OBJECTIVES: We assessed the prevalence of SARS-CoV-2 infection, personal protective equipment (PPE) shortages and occurrence of biological accidents among front-line healthcare workers (HCW). DESIGN, SETTING AND PARTICIPANTS: Using respondent-driven sampling, the study recruited distinct categories of HCW attending suspected or confirmed patients with COVID-19 from May 2020 to February 2021, in the Recife metropolitan area, Northeast Brazil. OUTCOME MEASURES: The criterion to assess SARS-CoV-2 infection among HCW was a positive self-reported PCR test. RESULTS: We analysed 1525 HCW: 527 physicians, 471 registered nurses, 263 nursing assistants and 264 physical therapists. Women predominated in all categories (81.1%; 95% CI: 77.8% to 84.1%). Nurses were older with more comorbidities (hypertension and overweight/obesity) than the other staff. The overall prevalence of SARS-CoV-2 infection was 61.8% (95% CI: 55.7% to 67.5%) after adjustment for the cluster random effect, weighted by network, and the reference population size. Risk factors for a positive RT-PCR test were being a nursing assistant (OR adjusted: 2.56; 95% CI: 1.42 to 4.61), not always using all recommended PPE while assisting patients with COVID-19 (OR adj: 2.15; 95% CI: 1.02 to 4.53) and reporting a splash of biological fluid/respiratory secretion in the eyes (OR adj: 3.37; 95% CI: 1.10 to 10.34). CONCLUSIONS: This study shows the high frequency of SARS-CoV2 infection among HCW presumably due to workplace exposures. In our setting, nursing assistant comprised the most vulnerable category. Our findings highlight the need for improving healthcare facility environments, specific training and supervision to cope with public health emergencies.

[Covid-19 in the Northeast of Brazil: from lockdown to the relaxation of social distancing measures]. / Covid-19 no nordeste do Brasil: entre o lockdown e o relaxamento das medidas de distanciamento social.

Even in the period when the Covid-19 pandemic was on the rise in the Northeast of Brazil, the relaxation of social distancing measures was introduced. The scope of the study is to assess, in the light of the epidemiological-sanitary situation in the region, the suitability of relaxation of social distancing measures. Based on the WHO guidelines for relaxation of social distancing, operational indicators were created and analyzed for each guideline in the context of the Northeast. To analyze the behavior of the epidemic, according to selected indicators, Joinpoint trend analysis techniques, heat maps, rate ratios and time trends between capitals and the state interior were compared. The weekly growth peak of the epidemic occurred in May-July 2020 (epidemiological weeks 19 to 31). In most capitals, there was no simultaneous downward trend in the number of cases and deaths in the 14 days prior to flexibilization. In all states the number of tests performed was insufficient. In epidemiological week 24, the state percentages of ICU/Covid-19 bed occupancy were close to or above 70%. The epidemiological situation of the nine Northeastern state capitals analyzed here did not meet criteria and parameters recommended by the World Health Organization for the relaxation of social distancing measures.

Mesmo no período em que a pandemia de Covid-19 encontrava-se em crescimento no Nordeste do Brasil, iniciou-se a adoção de medidas de flexibilização do distanciamento social. O objetivo do estudo é o de avaliar a pertinência das propostas de flexibilização, tomando-se em conta a situação da pandemia em cada local e o momento em que foram adotadas. Tendo como referência as diretrizes da OMS, foram construídos e analisados indicadores operacionais para cada diretriz, no contexto da região Nordeste. Para análise do comportamento da epidemia, conforme indicadores selecionados, foram usadas técnicas de Joinpoint Trend Analysis, mapas de calor, razão de taxas e comparação da tendência temporal entre capitais e interior dos estados. O pico do crescimento semanal ocorreu em maio-julho/2020 (semanas epidemiológicas 19 a 31). Na maioria das capitais não se observou tendência decrescente simultânea do número de casos e óbitos nos 14 dias prévios à flexibilização. Em todos os estados o quantitativo de testes realizados foi insuficiente. Na semana epidemiológica 24 os percentuais estaduais de ocupação de leitos de UTI/Covid-19 foram próximos ou superiores 70%. A situação epidemiológica das nove capitais dos estados do Nordeste, no momento em que a decisão de flexibilização foi tomada, mostra que nenhuma delas atendia aos critérios e parâmetros recomendados pela OMS.