Nowcasting methods to improve the performance of respiratory sentinel surveillance: lessons from the COVID-19 pandemic.

Respiratory diseases, including influenza and coronaviruses, pose recurrent global threats. This study delves into the respiratory surveillance systems, focusing on the effectiveness of SARI sentinel surveillance for total and severe cases incidence estimation. Leveraging data from the COVID-19 pandemic in Chile, we examined 2020-2023 data (a 159-week period) comparing census surveillance results of confirmed cases and hospitalizations, with sentinel surveillance. Our analyses revealed a consistent underestimation of total cases and an overestimation of severe cases of sentinel surveillance. To address these limitations, we introduce a nowcasting model, improving the precision and accuracy of incidence estimates. Furthermore, the integration of genomic surveillance data significantly enhances model predictions. While our findings are primarily focused on COVID-19, they have implications for respiratory virus surveillance and early detection of respiratory epidemics. The nowcasting model offers real-time insights into an outbreak for public health decision-making, using the same surveillance data that is routinely collected. This approach enhances preparedness for emerging respiratory diseases by the development of practical solutions with applications in public health.

Impact of total indoor smoking ban on cardiovascular disease hospitalizations and mortality: the case of Chile.

INTRODUCTION: The harmful effects of first and secondhand smoking are well established. Smoke-free laws aim at protecting nonsmokers. This study aimed to assess the impact of the 2013 total ban on indoor smoking in Chile on hospitalizations and deaths of major cardiovascular events. METHODS: The logarithm of the monthly hospitalization and death rates, standardized by age for every 100,000 inhabitants, were estimated for ischemic heart disease, acute myocardial infarction, strokes, and a composite outcome of ischemic heart diseases (which includes acute myocardial infarction) and strokes. In addition, interrupted time series with synthetic control groups were used to assess changes in levels and trends after the intervention. RESULTS: The total ban on indoor smoking caused significant reductions in death rates for the three diseases studied for age groups above 20 years old. In addition, there were substantial decreases in the postintervention hospitalization rates for ischemic heart disease: for the 20-44 age group, the decrease was 8.7% compared to the pre-intervention period (p<0.01). In comparison, such a reduction was 4% (p<0.01) for the ≥65 age group. For acute myocardial infarction, the decrease was 11.5% (p<0.01) for the 20-44 age group, while for stroke, it was a 1.2% (p<0.01) decrease for the total population. It is estimated that the smoking ban averted 15.6% of the deaths compared with the synthetic control groups. CONCLUSIONS: The implementation of total smoke-free environments in Chile contributed to the reduction of mortality for main cardiovascular diseases. This study provides additional evidence of causality linking the policy to health outcomes. IMPLICATIONS: The total indoor smoking ban significantly affected age-standardized hospitalization and deaths. The number of deaths averted by this policy is estimated at approximately 4,758 and 5,256 for IHD and stroke, respectively, during the 2013-2017 period (15.6% fewer deaths than predicted by the synthetic control groups). The study contributes to the body of evidence that supports total indoor smoking bans.

Effectiveness of the second COVID-19 booster against Omicron: a large-scale cohort study in Chile.

In light of the ongoing COVID-19 pandemic and the emergence of new SARS-CoV-2 variants, understanding the effectiveness of various booster vaccination regimens is pivotal. In Chile, using a prospective national cohort of 3.75 million individuals aged 20 or older, we evaluate the effectiveness against COVID-19-related intensive care unit (ICU) admissions and death of mRNA-based second vaccine boosters for four different three-dose background regimes: BNT162b2 primary series followed by a homologous booster, and CoronaVac primary series followed by an mRNA booster, a homologous booster, and a ChAdOx-1 booster. We estimate the vaccine effectiveness weekly from February 14 to August 15, 2022, by determining hazard ratios of immunization over non-vaccination, accounting for relevant confounders. The overall adjusted effectiveness of a second mRNA booster shot is 88.2% (95%CI, 86.2-89.9) against ICU admissions and 90.5% (95%CI 89.4-91.4) against death. Vaccine effectiveness shows a mild decrease for all regimens and outcomes, probably linked to the introduction of BA.4 and BA.5 Omicron sub-lineages and the waning of immunity. Based on our findings, individuals might not need additional boosters for at least 6 months after receiving a second mRNA booster shot in this setting.

What is the impact of forced displacement on health? A scoping review.

While there is a broad literature analysing the effects of migration on health, important knowledge gaps persist particularly on the causal effects of forced displacement on health outcomes. We undertake a scoping review of applied epidemiological, statistical and econometric studies examining causal health impacts of forced displacement, which initially identified 1454 studies from the health and social sciences disciplines published up to May 2021. Our study makes two key contributions. First, we offer a comprehensive overview of the evidence generated, methodologies adopted and analytical challenges faced by current research examining the causal relationship between forced displacement and health. Second, we present concrete examples of how key challenges around study design and estimation approaches influence the strength of the evidence-base on the topic, using as a case study the broad domain of reproductive health. We find that, beyond the increased mortality risk that can be attributed to forced displacement, most of the available empirical evidence for a wide range of health outcomes is prone to substantial bias, making it difficult to draw firm conclusions. Our synthesis of credible studies conducted in different settings indicates that current research practice in the field could be strengthened through selection of valid control groups and application of more appropriate causal inference methods. Our findings are useful to promote the generation of further evidence on the topic that can reliably inform the design of policies to protect the health of displaced populations.

Influenza Incidence and Vaccine Effectiveness During the Southern Hemisphere Influenza Season - Chile, 2022.

The COVID-19 pandemic has affected influenza virus transmission, with historically low activity, atypical timing, or altered duration of influenza seasons during 2020-22 (1,2). Community mitigation measures implemented since 2020, including physical distancing and face mask use, have, in part, been credited for low influenza detections globally during the pandemic, compared with those during prepandemic seasons (1). Reduced population exposure to natural influenza infections during 2020-21 and relaxed community mitigation measures after introduction of COVID-19 vaccines could increase the possibility of severe influenza epidemics. Partners in Chile and the United States assessed Southern Hemisphere influenza activity and estimated age-group-specific rates of influenza-attributable hospitalizations and vaccine effectiveness (VE) in Chile in 2022. Chile's most recent influenza season began in January 2022, which was earlier than during prepandemic seasons and was associated predominantly with influenza A(H3N2) virus, clade 3C.2a1b.2a.2. The cumulative incidence of influenza-attributable pneumonia and influenza (P&I) hospitalizations was 5.1 per 100,000 person-years during 2022, which was higher than that during 2020-21 but lower than incidence during the 2017-19 influenza seasons. Adjusted VE against influenza A(H3N2)-associated hospitalization was 49%. These findings indicate that influenza activity continues to be disrupted after emergence of SARS-CoV-2 in 2020. Northern Hemisphere countries might benefit from preparing for an atypical influenza season, which could include early influenza activity with potentially severe disease during the 2022-23 season, especially in the absence of prevention measures, including vaccination. Health authorities should encourage all eligible persons to seek influenza vaccination and take precautions to reduce transmission of influenza (e.g., avoiding close contact with persons who are ill).

Cancer Care Access in Chile's Vulnerable Populations During the COVID-19 Pandemic.

Objectives. To examine the COVID-19 pandemic's impact on cancer care access in Chile, analyzing differential effects by insurance type, gender, and age. Methods. We conducted a quasi-experimental study using interrupted time series analysis. We used multiple data sources for a broad evaluation of cancer-related health care utilization from January 2017 to December 2020. We fit negative binomial models by population groups for a range of services and diagnoses. Results. A sharp drop in oncology health care utilization in March was followed by a slow, incomplete recovery over 2020. Cumulative cancer-related services, diagnostic confirmations, and sick leaves were reduced by one third in 2020; the decrease was more pronounced among women and the publicly insured. Early diagnosis was missed in 5132 persons with 4 common cancers. Conclusions. The pandemic stressed the Chilean health system, decreasing access to essential services, with a profound impact on cancer care. Oncology service reductions preceded large-scale lockdowns and supply-side disruptions. Importantly, not all population groups were equally affected, with patterns suggesting that gender and socioeconomic inequalities were exacerbated. (Am J Public Health. 2022;112(S6):S591-S601. https://doi.org/10.2105/AJPH.2021.306587).

[Cancer care access in Chile's vulnerable populations during the COVID-19 pandemicAcesso a tratamento de câncer em populações vulneráveis no Chile durante a pandemia de COVID-19]. / Acceso a la atención del cáncer en los grupos vulnerables de Chile durante la pandemia de COVID-19.

Objectives: To examine the COVID-19 pandemic's impact on cancer care access in Chile, analyzing differential effects by insurance type, gender, and age. Methods: We conducted a quasi-experimental study using interrupted time series analysis. We used multiple data sources for a broad evaluation of cancer-related health care utilization from January 2017 to December 2020. We fit negative binomial models by population groups for a range of services and diagnoses. Results: A sharp drop in oncology health care utilization in March was followed by a slow, incomplete recovery over 2020. Cumulative cancer-related services, diagnostic confirmations, and sick leaves were reduced by one third in 2020; the decrease was more pronounced among women and the publicly insured. Early diagnosis was missed in 5132 persons with 4 common cancers. Conclusions: The pandemic stressed the Chilean health system, decreasing access to essential services, with a profound impact on cancer care. Oncology service reductions preceded large-scale lockdowns and supply-side disruptions. Importantly, not all population groups were equally affected, with patterns suggesting that gender and socioeconomic inequalities were exacerbated.

Objetivos: Examinar o impacto da pandemia de COVID-19 no acesso a tratamento de câncer no Chile, analisando efeitos diferenciais por tipo de cobertura de assistência à saúde, gênero e idade. Métodos: Realizamos um estudo quase-experimental utilizando análise de séries temporais interrompidas. A partir de várias fontes de dados, efetuamos uma avaliação abrangente da utilização de atenção à saúde relacionada ao câncer, de janeiro de 2017 a dezembro de 2020. Ajustamos modelos binomiais negativos por grupos populacionais a vários tipos de serviços e diagnósticos. Resultados: Uma queda acentuada no uso da assistência médica oncológica em março foi seguida por uma recuperação lenta e incompleta ao longo de 2020. Cumulativamente, a utilização de serviços oncológicos, as confirmações de diagnóstico e os afastamentos do trabalho por doença foram reduzidos em um terço em 2020. Essa redução foi mais pronunciada em mulheres e usuários do sistema público de saúde. No total, 5132 pessoas com 4 cânceres comuns não foram diagnosticadas precocemente. Conclusões: A pandemia impôs pressão sobre o sistema de saúde chileno, reduzindo o acesso a serviços essenciais e causando um profundo impacto no tratamento do câncer. As reduções na prestação de serviços de oncologia precederam os lockdowns em larga escala e as interrupções na oferta de suprimentos. É importante ressaltar que nem todos os grupos populacionais foram igualmente afetados e os padrões observados sugerem que as desigualdades de gênero e socioeconômicas foram exacerbadas.

Detección de Nuevas Tecnologías Sanitarias Para Mejorar el Control Metabólico de Pacientes Con Diabetes Tipo 2 Atendidos en el Programa de Salud Cardiovascular de Chile.

OBJECTIVES: In Chile, > 900,000 people with type 2 diabetes mellitus (DM2) are controlled in the Cardiovascular Health Program (PSCV). Even though the PSCV includes a set of interventions for the control of patients with DM2, the results are still insufficient, generating a high human, economic, and social cost. This study aimed to identify and select new health technologies for the control of patients with DM2 not currently incorporated into the PSCV to be proposed as candidates for an economic evaluation in the Chilean context. METHODS: For the identification of new health technologies, consultations with key informants and an umbrella review of updated scientific evidence were used as sources of information. In a second step, selection among those technologies was conducted based on the effectiveness of the intervention, target population, nature of the intervention, and international evidence of cost-effectiveness antecedents. RESULTS: Key informants identified 12 candidate health technologies not currently incorporated into the PSCV. From the umbrella review, an additional 9 health technologies were identified that were not identified by the key informants. Of the 21 new health technologies identified, finally 8 health technologies were selected (structured group education, pedometer use, periodontal treatment, cognitive-behavioral therapy, telemonitoring, sitagliptin, canagliflozin, and insulin degludec). CONCLUSIONS: The health technologies detected have a high potential to be studied through economic evaluations that allow guiding decision making around improving the health outcomes of patients with DM2 in Chile.

Acceso a la atención del cáncer en los grupos vulnerables de Chile durante la pandemia de COVID-19 / Cancer care access in Chile's vulnerable populations during the COVID-19 pandemic / Acesso a tratamento de câncer em populações vulneráveis no Chile durante a pandemia de COVID-19

RESUMEN Objetivo. Estudiar la repercusión de la pandemia de COVID-19 en el acceso a la atención del cáncer en Chile, analizando los efectos diferenciales por tipo de seguro, sexo y edad. Métodos. Se llevó a cabo un estudio cuasiexperimental mediante análisis de series temporales interrumpidas. Se recurrió a fuentes de datos múltiples con el fin de lograr una evaluación amplia de la utilización de la atención del cáncer de enero del 2017 a diciembre del 2020. Se ajustaron modelos binomiales negativos en función de los grupos de población para una diversidad de servicios y diagnósticos. Resultados. Tras una disminución considerable de la utilización de la atención oncológica en marzo, se observó una recuperación lenta e incompleta durante el 2020. Los servicios de atención del cáncer, las confirmaciones diagnósticas y las licencias por enfermedad acumulados se redujeron en un tercio en el 2020; la disminución fue más pronunciada en las mujeres y las personas afiliadas al seguro de enfermedad público. No se hizo un diagnóstico temprano en 5132 personas con cuatro tipos frecuentes de cáncer. Conclusiones. La pandemia sobrecargó el sistema de salud chileno y provocó una disminución del acceso a los servicios básicos, con una repercusión profunda en la atención del cáncer. La reducción de los servicios de oncología precedió los confinamientos a gran escala y las interrupciones por parte de los prestadores. Cabe destacar que no todos los grupos de la población se vieron afectados por igual y se observaron pautas que indican un agravamiento de las desigualdades por situación socioeconómica y sexo.

ABSTRACT Objectives. To examine the COVID-19 pandemic's impact on cancer care access in Chile, analyzing differential effects by insurance type, gender, and age. Methods. We conducted a quasi-experimental study using interrupted time series analysis. We used multiple data sources for a broad evaluation of cancer-related health care utilization from January 2017 to December 2020. We fit negative binomial models by population groups for a range of services and diagnoses. Results. A sharp drop in oncology health care utilization in March was followed by a slow, incomplete recovery over 2020. Cumulative cancer-related services, diagnostic confirmations, and sick leaves were reduced by one third in 2020; the decrease was more pronounced among women and the publicly insured. Early diagnosis was missed in 5132 persons with 4 common cancers. Conclusions. The pandemic stressed the Chilean health system, decreasing access to essential services, with a profound impact on cancer care. Oncology service reductions preceded large-scale lockdowns and supply-side disruptions. Importantly, not all population groups were equally affected, with patterns suggesting that gender and socioeconomic inequalities were exacerbated.

RESUMO Objetivos. Examinar o impacto da pandemia de COVID-19 no acesso a tratamento de câncer no Chile, analisando efeitos diferenciais por tipo de cobertura de assistência à saúde, gênero e idade. Métodos. Realizamos um estudo quase-experimental utilizando análise de séries temporais interrompidas. A partir de várias fontes de dados, efetuamos uma avaliação abrangente da utilização de atenção à saúde relacionada ao câncer, de janeiro de 2017 a dezembro de 2020. Ajustamos modelos binomiais negativos por grupos populacionais a vários tipos de serviços e diagnósticos. Resultados. Uma queda acentuada no uso da assistência médica oncológica em março foi seguida por uma recuperação lenta e incompleta ao longo de 2020. Cumulativamente, a utilização de serviços oncológicos, as confirmações de diagnóstico e os afastamentos do trabalho por doença foram reduzidos em um terço em 2020. Essa redução foi mais pronunciada em mulheres e usuários do sistema público de saúde. No total, 5132 pessoas com 4 cânceres comuns não foram diagnosticadas precocemente. Conclusões. A pandemia impôs pressão sobre o sistema de saúde chileno, reduzindo o acesso a serviços essenciais e causando um profundo impacto no tratamento do câncer. As reduções na prestação de serviços de oncologia precederam os lockdowns em larga escala e as interrupções na oferta de suprimentos. É importante ressaltar que nem todos os grupos populacionais foram igualmente afetados e os padrões observados sugerem que as desigualdades de gênero e socioeconômicas foram exacerbadas.

Gender disparities in access to care for time-sensitive conditions during COVID-19 pandemic in Chile.

BACKGROUND: During the COVID-19 pandemic, reductions in healthcare utilization are reported in different contexts. Nevertheless, studies have not explored specifically gender disparities in access to healthcare in the context of COVID-19. METHODS: To evaluate gender disparities in access to medical in Chile we conducted an interrupted time series analysis using segmented regression. The outcome variable was the number of weekly confirmed cases of a set of oncologic and cardiovascular time-sensitive conditions at a national level. The series contained data from weeks 1 to 39 for 2017 to 2020. The intervention period started at week 12. We selected this period because preventive interventions, such as school closures or teleworking, were implemented at this point. We estimated the level effect using a dummy variable indicating the intervention period and slope effect using a continuous variable from weeks 12 to 39. To test heterogeneity by gender and age group, we conducted a stratified analysis. RESULTS: We observed a sizable reduction in access to care with a slowly recovery for oncologic (level effect 0.323; 95% CI 0.291-0.359; slope effect 1.022; 95% CI 1.016-1.028) and cardiovascular diseases (level effect 0.586; 95% CI 0.564-0.609; slope effect 1.009; 95% CI 1.007-1.011). Greater reduction occurred in women compared to men, particularly marked on myocardial infarction (level effect 0.595; 95% CI 0.566-0.627 versus 0.532; 95% CI 0.502-0.564) and colorectal cancer (level effect 0.295; 95% CI 0.248-0.35 versus 0.19; 95% CI 0.159-0.228). Compared to men, a greater absolute reduction was observed in women for oncologic diseases, excluding sex-specific cancer, (1352; 95% CI 743-1961) and cardiovascular diseases (1268; 95% CI 946-1590). CONCLUSION: We confirmed a large drop in new diagnoses for time-sensitive conditions during the COVID-19 pandemic in Chile. This reduction was greater for women. Our findings should alert policy-makers about the urgent need to integrate a gender perspective into the pandemic response.

Taking Care of Each Other: How Can We Increase Compliance with Personal Protective Measures During the COVID-19 Pandemic in Chile?

In the context of the COVID-19 pandemic, personal protective measures (e.g., social distancing, handwashing, and mask wearing) have been adopted as a cornerstone to limit the spread of the disease. Yet, the effectiveness of these measures depends on people's levels of adherence. In this article, we apply social-psychological research to the study of compliance with personal protective measures during the COVID-19 pandemic in Chile. We consider three possible models underlying adherence: (1) sociodemographic and socioeconomic factors, (2) instrumental factors, and (3) normative factors. We draw on data from a longitudinal nonrepresentative panel study (Study 1, n = 32,304) and a cross-sectional representative survey (Study 2, n = 1,078) to explore the impact of these different factors on personal protective measures compliance. Findings show the strongest support for the role of instrumental and normative factors, in that people who comply with protective measures report to a greater extent that relatives and friends comply too and tend to perceive high risk of COVID-19. We finish by proposing policy recommendations to promote effective strategies to contain the spread of the virus.

Effectiveness of a Gamification Strategy to Prevent Childhood Obesity in Schools: A Cluster Controlled Trial.

OBJECTIVE: The aim of this study was to examine the effectiveness of a school-based gamification strategy to prevent childhood obesity. METHODS: Schools were randomized in Santiago, Chile, between March and May 2018 to control or to receive a nutrition and physical activity intervention using a gamification strategy (i.e., the use of points, levels, and rewards) to achieve healthy challenges. The intervention was delivered for 7 months and participants were assessed at 4 and 7 months. Primary outcomes were mean difference in BMI z score and waist circumference (WC) between trial arms at 7 months. Secondary outcomes were mean difference in BMI and systolic and diastolic blood pressure between trial arms at 7 months.  RESULTS: A total of 24 schools (5 controls) and 2,197 students (653 controls) were analyzed. Mean BMI z score was lower in the intervention arm compared with control (adjusted mean difference -0.133, 95% CI: -0.25 to -0.01), whereas no evidence of reduction in WC was found. Mean BMI and systolic blood pressure were lower in the intervention arm compared with control. No evidence of reduction in diastolic blood pressure was found. CONCLUSIONS: The multicomponent intervention was effective in preventing obesity but not in reducing WC. Gamification is a potentially powerful tool to increase the effectiveness of school-based interventions to prevent obesity.

Association between gender inequality and population-level health outcomes: Panel data analysis of organization for Economic Co-operation and Development (OECD) countries.

BACKGROUND: Gender plays a well-recognized role in shaping health inequities. However, the population-level health consequences of gender inequalities have not been measured comprehensively. The goal of this study was to evaluate the association between gender inequality and health indicators in organization for Economic Co-operation and Development (OECD) countries. METHODS: Ecological study based on 1990-2017 panel data for OECD member countries. Gender inequality was measured using the Gender Inequality Index (GII). The population health parameters evaluated were life expectancy (LE), healthy life expectancy (HALE), years of life lost (YLL), years lived with disability (YLD), disability-adjusted life years (DALYs), and specific-cause mortality. Two-way fixed-effects linear models were used to assess the relationship between gender inequality and health outcomes. Models included potential mediating and confounding factors such as health spending, political model, and income inequalities. FINDINGS: Greater gender inequality was associated with lower LE (-0·49%; CI95 -0·63%- -0·31%; p-value < 0·0001), HALE (-0·47%; CI95 -0·63%- -0·31%; p-value < 0·0001) and with increased premature mortality YLL (6·82%; CI95 3·63%-10·75%; p-value < 0·0001) and morbidity measured in DALYs (1·50%; CI95 0·48%-2·46%; p-value = 0·0028) and YLD (2·59%; CI95 0·67%-4·77%; p-value = 0·0063) for each 0·1 increments on the GII. The sensitivity analysis indicated that the results were robust to the various specifications of the causal models. INTERPRETATION: Our results suggest that gender inequality pose a sizable impact on population health outcomes. Promoting gender equality as part of public policies is vital for optimizing health on a population scale. FUNDING: Agencia Nacional de Investigación y Desarrollo (ANID)/Programa Becas/Magister Becas Chile/2017- 22,170,332.

[Diagnostic properties of case definitions of suspected COVID-19 in Chile, 2020Características diagnósticas das definições de caso suspeito de COVID-19 no Chile, 2020]. / Propiedades diagnósticas de las definiciones de caso sospechoso de COVID-19 en Chile, 2020.

OBJECTIVE: Compare the diagnostic properties of five case definitions of suspected COVID-19 that were used or proposed in Chile during the first eight months of the pandemic. METHODS: An analysis was done of the diagnostic properties (sensitivity, specificity, and positive and negative predictive values) of three case definitions of suspected COVID-19 used in Chile between March and October 2020, as well as two alternative proposed definitions. The sample was 2,019 people with known results for the polymerase chain reaction (PCR) test for SARS-CoV-2. Stepwise logistic regression was used to develop criterion 5, optimizing sensitivity and specificity values. Multifactor logistic regression was used to explore the association between demographic variables, symptoms and signs, and PCR positivity. Different positivity scenarios were analyzed and ROC curves were compared. RESULTS: The presence of anosmia (OR = 8.00; CI95%: 5.34-11.99), fever (OR = 2.15; CI95%: 1.28-3.59), and having been in close contact with a person sick with COVID-19 (OR = 2.89; CI95%: 2.16-3.87) were associated with a positive PCR result. According to the analysis of the ROC curve, criterion 5 had the highest capacity for discrimination, although there were no significant differences with the other four criteria. CONCLUSIONS: Criterion 5-based on anosmia, close contact with people with COVID-19, and fever as sufficient unique elements-was the most sensitive in identifying suspected cases of COVID-19, a key aspect in controlling the spread of the pandemic.

OBJETIVO: Comparar as características diagnósticas de cinco critérios das definições de caso suspeito de COVID-19 usados ou propostos no Chile nos oito primeiros meses de pandemia. MÉTODOS: Foram avaliadas as características diagnósticas (sensibilidade, especificidade e valores preditivos positivo e negativo) de três critérios das definições de caso suspeito de COVID-19 usados no Chile entre março e outubro de 2020 e de duas alternativas propostas para definição de caso. A amostra do estudo consistiu 2 019 pessoas com resultados conhecidos no exame de reação em cadeia da polimerase (PCR) para SARS-CoV-2. Para elaborar o critério 5, uma regressão logística com método stepwise foi realizada otimizando os valores de sensibilidade e especificidade. A associação entre variáveis demográficas, sintomas e sinais e resultado positivo no exame de PCR foi testada em um modelo de regressão logística multifatorial. Situações diferentes de resultado positivo foram testadas com uma análise comparativa das curvas ROC. RESULTADOS: Presença de anosmia (OR 8,00; IC95% 5,34­11,99), febre (OR 2,15; IC95% 1,28­3,59) e contato próximo anterior com uma pessoa com COVID-19 (OR 2,89; IC95% 2,16­3,87) foram associados a um resultado positivo no exame de PCR. De acordo com a análise das curvas ROC, o critério 5 demonstrou maior capacidade discriminatória, apesar de não existir diferença significativa com os outros quatro critérios. CONCLUSÃO: O critério 5 ­ presença de anosmia, febre e contato próximo com uma pessoa com COVID-19 como elementos únicos e suficientes ­ demonstrou maior sensibilidade para identificar casos suspeitos de COVID-19, o que é fundamental para controlar a disseminação da pandemia.

COVID-19 in Chile: The usefulness of simple epidemic models in practice. / COVID-19 en Chile: la utilidad de los modelos epidémicos simples en la práctica.

OBJECTIVES: The purpose of this article is to describe and develop the predictive value of three models during the COVID-19 epidemic in Chile, providing knowledge for decision-making in health. METHODS: We developed three models during the epidemic: a discrete model to predict the maximum burden on the health system in a short time framea basic SEIR (susceptible-exposed-infected-removed) model with discrete equations; a stochastic SEIR model with the Monte Carlo method; and a Gompertz-type model for metropolitan city of Santiago. RESULTS: The maximum potential burden model has been useful throughout the monitoring of the epidemic, providing an upper bound for the number of cases, intensive care unit occupancy, and deaths. Deterministic and stochastic SEIR models were very useful in predicting the rise of cases and the peak and onset of case decline; however, they lost utility in the current situation due to the asynchronous recruitment of cases in the regions and the persistence of a strong endemic. The Gompertz model had a better fit in the decline since it best captures the epidemic curves asymmetry in Santiago. CONCLUSIONS: The models have shown great utility in monitoring the epidemic in Chile, with different objectives in different epidemic stages. They have complemented empirical indicators such as reported cases, fatality, deaths, and others, making it possible to predict situations of interest and visualization of the short and long-term local behavior of this pandemic.

OBJETIVOS: El objetivo general ha sido describir y evaluar el valor predictivo de tres modelos durante el desarrollo de la epidemia COVID-19 en Chile, aportando conocimiento para la toma de decisiones en salud. MÉTODOS: Desarrollamos tres modelos a lo largo de la epidemia: un modelo discreto para predecir a corto tiempo la máxima carga sobre el sistema de salud, un modelo básico SEIR (susceptibles-expuestos-infectados-removidos) con ecuaciones discretas; un modelo SEIR estocástico con método de Montecarlo; y un modelo de tipo Gompertz para la Región Metropolitana (Santiago). RESULTADOS: El modelo de máxima carga potencial ha sido útil durante todo el seguimiento de la epidemia proporcionando una cota superior para el número de casos, la ocupación de unidades de cuidados intensivos y el número de fallecidos. Los modelos SEIR determinístico y estocástico tuvieron gran utilidad en la predicción del ascenso de los casos, el máximo y el inicio del descenso de casos, perdiendo utilidad en la situación actual por el reclutamiento asincrónico de casos en las regiones y la persistencia de una endemia alta. El modelo de Gompertz ha tenido un mejor ajuste en el descenso ya que esta captura mejor la asimetría de la curva epidémica en Santiago. CONCLUSIONES: Los modelos han demostrado gran utilidad en el seguimiento de la epidemia en Chile, con distintos objetivos en distintas etapas de la epidemia. Han complementado los indicadores empíricos como casos reportados, letalidad, fallecimientos y otros, permitiendo predecir situaciones de interés y visualizar la conducta a corto y largo plazo de esta pandemia a nivel local.

Understanding policy change for obesity prevention: learning from sugar-sweetened beverages taxes in Mexico and Chile.

This article examines the policy change process that resulted in the current sugar-sweetened beverages taxes in Mexico and Chile, using the Kaleidoscope Model for Policy Change, a framework developed for nutrition and food policy change analysis. We used a qualitative study design, including 24 key informant (KI) interviews (16 researchers, 5 civil society representatives and 3 food/beverage industry representatives), encompassing global and in-country perspectives. The analysis shows concurrence with the Kaleidoscope Model, highlighting commonalities in the policy change process. These included the importance of focusing events and coalitions for agenda-setting. Both top-down executive leadership and bottom-up pressure from civil society coalitions were important for the policy adoption as were flexible framing of the tax, and taking advantage of windows of opportunity. In both countries, the tax resulted from national, revenue-seeking fiscal reforms and in sub-optimal tax rates, as a result of the industry influence. KIs also discussed emerging evaluation results, highlighting differences in interpretation concerning the magnitude of change from the tax, and shared potential modifications to the current policies. This analysis contributes to a greater understanding of the policy change process focused on obesity prevention, using an innovative theoretical framework developed specifically for food and nutrition policy.

COVID-19 en Chile: la utilidad de los modelos epidémicos simples en la práctica / COVID-19 in Chile: the usefulness of simple epidemic models in practice

Objetivos El objetivo general ha sido describir y evaluar el valor predictivo de tres modelos durante el desarrollo de la epidemia COVID-19 en Chile, aportando conocimiento para la toma de decisiones en salud. Métodos Desarrollamos tres modelos a lo largo de la epidemia: un modelo discreto para predecir a corto tiempo la máxima carga sobre el sistema de salud, un modelo básico SEIR (susceptibles-expuestos-infectados-removidos) con ecuaciones discretas; un modelo SEIR estocástico con método de Montecarlo; y un modelo de tipo Gompertz para la Región Metropolitana (Santiago). Resultados El modelo de máxima carga potencial ha sido útil durante todo el seguimiento de la epidemia proporcionando una cota superior para el número de casos, la ocupación de unidades de cuidados intensivos y el número de fallecidos. Los modelos SEIR determinístico y estocástico tuvieron gran utilidad en la predicción del ascenso de los casos, el máximo y el inicio del descenso de casos, perdiendo utilidad en la situación actual por el reclutamiento asincrónico de casos en las regiones y la persistencia de una endemia alta. El modelo de Gompertz ha tenido un mejor ajuste en el descenso ya que esta captura mejor la asimetría de la curva epidémica en Santiago. Conclusiones Los modelos han demostrado gran utilidad en el seguimiento de la epidemia en Chile, con distintos objetivos en distintas etapas de la epidemia. Han complementado los indicadores empíricos como casos reportados, letalidad, fallecimientos y otros, permitiendo predecir situaciones de interés y visualizar la conducta a corto y largo plazo de esta pandemia a nivel local.

Objectives The purpose of this article is to describe and develop the predictive value of three models during the COVID-19 epidemic in Chile, providing knowledge for decision-making in health. Methods We developed three models during the epidemic: a discrete model to predict the maximum burden on the health system in a short time frame­a basic SEIR (susceptible-exposed-infected-removed) model with discrete equations; a stochastic SEIR model with the Monte Carlo method; and a Gompertz-type model for metropolitan city of Santiago. Results The maximum potential burden model has been useful throughout the monitoring of the epidemic, providing an upper bound for the number of cases, intensive care unit occupancy, and deaths. Deterministic and stochastic SEIR models were very useful in predicting the rise of cases and the peak and onset of case decline; however, they lost utility in the current situation due to the asynchronous recruitment of cases in the regions and the persistence of a strong endemic. The Gompertz model had a better fit in the decline since it best captures the epidemic curve's asymmetry in Santiago. Conclusions The models have shown great utility in monitoring the epidemic in Chile, with different objectives in different epidemic stages. They have complemented empirical indicators such as reported cases, fatality, deaths, and others, making it possible to predict situations of interest and visualization of the short and long-term local behavior of this pandemic.

Propiedades diagnósticas de las definiciones de caso sospechoso de COVID-19 en Chile, 2020 / Diagnostic properties of case definitions of suspected COVID-19 in Chile, 2020 / Características diagnósticas das definições de caso suspeito de COVID-19 no Chile, 2020

RESUMEN Objetivo. Comparar las propiedades diagnósticas de cinco definiciones de caso sospechoso de COVID-19 utilizadas o propuestas en Chile durante los primeros ocho meses de la pandemia. Métodos. Se analizaron las propiedades diagnósticas (sensibilidad, especificidad, y valores predictivos positivo y negativo) de tres definiciones de caso sospechoso de COVID-19 utilizadas en Chile entre marzo y octubre del 2020, y dos propuestas de definición alternativas. La muestra fue de 2 019 personas con resultados conocidos a la prueba de la reacción en cadena de la polimerasa (PCR) para SARS-CoV-2. Para elaborar el criterio 5 se aplicó una regresión logística escalonada (stepwise) optimizando los valores de sensibilidad y especificidad. Se exploró la asociación de variables demográficas, síntomas y signos con la positividad a la PCR mediante regresión logística multifactorial. Se analizaron diferentes escenarios de positividad y se compararon las curvas ROC. Resultados. La presencia de anosmia (OR = 8,00; IC95%: 5,34-11,99) y fiebre (OR = 2,15; IC95%: 1,28-3,59) y el haber tenido contacto estrecho previo con una persona enferma de COVID-19 (OR = 2,89; IC95%: 2,16-3,87) se asociaron con un resultado positivo de la PCR. Según el análisis de las curvas ROC, el criterio 5 tuvo la mayor capacidad de discriminación, aunque sin diferencias significativas con los otros cuatro criterios. Conclusiones. El criterio 5 —basado en la anosmia, el contacto estrecho con personas enfermas de COVID-19 y la fiebre como elementos únicos suficientes— tuvo la mayor sensibilidad para identificar los casos sospechosos de COVID-19, aspecto fundamental para controlar la propagación de la pandemia.

ABSTRACT Objective. Compare the diagnostic properties of five case definitions of suspected COVID-19 that were used or proposed in Chile during the first eight months of the pandemic. Methods. An analysis was done of the diagnostic properties (sensitivity, specificity, and positive and negative predictive values) of three case definitions of suspected COVID-19 used in Chile between March and October 2020, as well as two alternative proposed definitions. The sample was 2,019 people with known results for the polymerase chain reaction (PCR) test for SARS-CoV-2. Stepwise logistic regression was used to develop criterion 5, optimizing sensitivity and specificity values. Multifactor logistic regression was used to explore the association between demographic variables, symptoms and signs, and PCR positivity. Different positivity scenarios were analyzed and ROC curves were compared. Results. The presence of anosmia (OR = 8.00; CI95%: 5.34-11.99), fever (OR = 2.15; CI95%: 1.28-3.59), and having been in close contact with a person sick with COVID-19 (OR = 2.89; CI95%: 2.16-3.87) were associated with a positive PCR result. According to the analysis of the ROC curve, criterion 5 had the highest capacity for discrimination, although there were no significant differences with the other four criteria. Conclusions. Criterion 5—based on anosmia, close contact with people with COVID-19, and fever as sufficient unique elements—was the most sensitive in identifying suspected cases of COVID-19, a key aspect in controlling the spread of the pandemic.

RESUMO Objetivo. Comparar as características diagnósticas de cinco critérios das definições de caso suspeito de COVID-19 usados ou propostos no Chile nos oito primeiros meses de pandemia. Métodos. Foram avaliadas as características diagnósticas (sensibilidade, especificidade e valores preditivos positivo e negativo) de três critérios das definições de caso suspeito de COVID-19 usados no Chile entre março e outubro de 2020 e de duas alternativas propostas para definição de caso. A amostra do estudo consistiu 2 019 pessoas com resultados conhecidos no exame de reação em cadeia da polimerase (PCR) para SARS-CoV-2. Para elaborar o critério 5, uma regressão logística com método stepwise foi realizada otimizando os valores de sensibilidade e especificidade. A associação entre variáveis demográficas, sintomas e sinais e resultado positivo no exame de PCR foi testada em um modelo de regressão logística multifatorial. Situações diferentes de resultado positivo foram testadas com uma análise comparativa das curvas ROC. Resultados. Presença de anosmia (OR 8,00; IC95% 5,34-11,99), febre (OR 2,15; IC95% 1,28-3,59) e contato próximo anterior com uma pessoa com COVID-19 (OR 2,89; IC95% 2,16-3,87) foram associados a um resultado positivo no exame de PCR. De acordo com a análise das curvas ROC, o critério 5 demonstrou maior capacidade discriminatória, apesar de não existir diferença significativa com os outros quatro critérios. Conclusão. O critério 5 - presença de anosmia, febre e contato próximo com uma pessoa com COVID-19 como elementos únicos e suficientes - demonstrou maior sensibilidade para identificar casos suspeitos de COVID-19, o que é fundamental para controlar a disseminação da pandemia.

Epidemic trends, public health response and health system capacity: the Chilean experience in four months of the COVID-19 pandemic.

OBJECTIVES: To report the surveillance of COVID-19 pandemic in Chile and analyse the response to public health interventions implemented from 3 March to 30 June 2020 and to assess the risks of collapse of the health care system. METHODS: We analysed the effective reproductive number, underreporting of cases, burden of critical beds, case fatality ratio and number of diagnostic RT-PCR for SARS-CoV-2. RESULTS: After an accelerated onset, the COVID-19 pandemic seemed to be relatively controlled in Chile (late April 2020), with reproductive numbers close to 1.00. However, at this time, the load of infected patients was high, with an important number of underreported cases; the diagnostic effort was still limited and heterogeneous across regions. After 1 May up to 30 June a marked exponential increase in the number of cases was observed with a peak on June 14. In this last period the occupation of intensive care unit beds increased to saturation level (89% nationally; 95% in the Metropolitan Region). CONCLUSIONS: Our findings suggest that the implemented public health interventions have been initially effective in decreasing the spread of the pandemic. Premature decisions to relax these interventions may have resulted in a rebound in cases with a rapid saturation of the health care system.

OBJETIVOS: Informar sobre la vigilancia de la pandemia por COVID-19 en Chile, analizar la respuesta a las intervenciones de salud pública implementadas desde el 3 de marzo hasta el 30 de junio de 2020 y evaluar los riesgos de colapso del sistema de salud. MÉTODOS: Se analizó el número reproductivo efectivo, el subregistro de casos, la carga sobre las camas de cuidados intensivos disponibles, la tasa de letalidad y el número de pruebas diagnósticas de RT-PCR efectuadas para el SARS-CoV-2. RESULTADOS: Tras un inicio acelerado, la pandemia por COVID-19 parecía estar relativamente controlada en Chile a finales de abril de 2020, con números reproductivos cercanos a 1,00. Sin embargo, en ese momento, la carga de pacientes infectados activos era elevada, con un número importante de casos no notificados; la capacidad diagnóstica era todavía limitada y heterogénea entre las regiones del país. Desde el 1 de mayo hasta el 30 de junio se observó un marcado incremento exponencial en el número de casos, con un pico el 14 de junio. En este último período la ocupación de camas en las unidades de cuidados intensivos aumentó hasta el nivel de saturación (89% a nivel nacional; 95% en la Región Metropolitana). CONCLUSIONES: Nuestros hallazgos sugieren que las intervenciones de salud pública implementadas parecen haber sido efectivas inicialmente para disminuir la propagación de la pandemia. Las decisiones prematuras de relajar estas intervenciones pueden haber ocasionado un rebote en los casos con una rápida saturación del sistema de atención de salud.