Vaccine effectiveness in reducing COVID-19-related hospitalization after a risk-age-based mass vaccination program in a Chilean municipality: A comparison of observational study designs.

BACKGROUND: Case-control studies involving test-negative (TN) and syndrome-negative (SN) controls are reliable for evaluating influenza and rotavirus vaccine effectiveness (VE) during a random vaccination process. However, there is no empirical evidence regarding the impact in real-world mass vaccination campaigns against SARS-CoV-2 using TN and SN controls. OBJECTIVE: To compare in the same population the effectiveness of SARS-CoV-2 vaccination on COVID-19-related hospitalization rates across a cohort design, TN and SN designs. METHOD: We conducted an unmatched population-based cohort, TN and SN case-control designs linking data from four data sources (public primary healthcare system, hospitalization registers, epidemiological surveillance systems and the national immunization program) in a Chilean municipality (Rancagua) between March 1, 2021 and August 31, 2021. The outcome was COVID-19-related hospitalization. To ensure sufficient sample size in the unexposed group, completion of follow-up in the cohort design, and sufficient time between vaccination and hospitalization in the case-control design, VE was estimated comparing 8-week periods for each individual. RESULTS: Among the 191,505 individuals registered in the primary healthcare system of Rancagua in Chile on March 1, 2021; 116,453 met the cohort study's inclusion criteria. Of the 9,471 hospitalizations registered during the study period in the same place, 526 were COVID-19 cases, 108 were TN controls, and 1,628 were SN controls. For any vaccine product, the age- and sex-adjusted vaccine effectiveness comparing fully and nonvaccinated individuals was 67.2 (55.7-76.3) in the cohort design, whereas it was 67.8 (44.1-81.4) and 77.9 (70.2-83.8) in the TN and SN control designs, respectively. CONCLUSION: The VE of a COVID-19 vaccination program based on age and risk groups tended to differ across the three observational study designs. The SN case-control design may be an efficient option for evaluating COVID-19 VE in real-world settings.

The added effect of non-pharmaceutical interventions and lifestyle behaviors on vaccine effectiveness against severe COVID-19 in Chile: A matched case-double control study.

BACKGROUND: World Health Organization approved vaccines have demonstrated relatively high protection against moderate to severe COVID-19. Prospective vaccine effectiveness (VE) designs with first-hand data and population-based controls are nevertheless rare. Neighborhood compared to hospitalized controls, may differ in compliance to non-pharmacuetical interventions (NPI) compliance, which may influence VE results in real-world settings. We aimed to determine VE against COVID-19 intensive-care-unit (ICU) admission using hospital and community-matched controls in a prospective design. METHODS: We conducted a multicenter, observational study of matched cases and controls (1:3) in adults ≧18 years of age from May to July 2021. For each case, a hospital control and two community controls were matched by age, gender, and hospital admission date or neighborhood of residence. Conditional logistic regression models were built, including interaction terms between NPIs, lifestyle behaviors, and vaccination status; the model's ß coefficients represent the added effect these terms had on COVID-19 VE. RESULTS: Cases and controls differed in several factors including education level, obesity prevalence, and behaviors such as compliance with routine vaccinations, use of facemasks, and routine handwashing. VE was 98·2% for full primary vaccination and 85·6% for partial vaccination when compared to community controls, and somewhat lower, albeit not significantly, compared to hospital controls. A significant added effect to vaccination in reducing COVID-19 ICU admission was regular facemask use and VE was higher among individuals non-compliant with the national vaccine program, and/or tonroutine medical visits during the prior year. CONCLUSION: VE against COVID-19 ICU admission in this stringent prospective case-double control study reached 98% two weeks after full primary vaccination, confirming the high effectiveness provided by earlier studies. Face mask use and hand washing were independent protective factors, the former adding additional benefit to VE. VE was significantly higher in subjects with increased risk behaviors.

Dynamic IgG seropositivity after rollout of CoronaVac and BNT162b2 COVID-19 vaccines in Chile: a sentinel surveillance study.

BACKGROUND: By July 14, 2021, 81·3 % of adults (aged ≥18 years) in Chile had received a first SARS-CoV-2 vaccine and 72·3% had received a second SARS-CoV-2 vaccine, with the majority of people given Sinovac's inactivated CoronaVac vaccine (75·3% of vaccines dispensed) or Pfizer-BioNTech's mRNA BNT162b2 vaccine (20·9% of vaccines dispensed). Due to the absence of simultaneous real-world data for these vaccines, we aimed to compare SARS-CoV-2 IgG positivity between vaccines using a dynamic national monitoring strategy. METHODS: From March 12, 2021, 28 testing stations for SARS-CoV-2 IgG detection were installed in hotspots based on cellular-phone mobility tracking within the most populated cities in Chile. Individuals voluntarily approaching the testing stations were invited to do a lateral flow test by finger prick and respond to a questionnaire on sociodemographic characteristics, vaccination status (including type of vaccine if one was received), variables associated with SARS-CoV-2 exposure, and comorbidities. We compared the proportion of individuals testing positive for anti-SARS-CoV-2 IgG across sites by week since vaccination between recipients of CoronaVac and BNT162b2. Unvaccinated participants served as a control population and were matched to vaccinated individuals on the basis of date of presentation to the testing station, gender, and age group. Individuals were excluded from the analysis if they were younger than 18 years, had no declared gender, had an invalid IgG test result, had previously tested positive for SARS-CoV-2 infection on PCR, could not recall their vaccination status, or had been immunised against COVID-19 with vaccines other than CoronaVac or BNT162b2. Here, we report data collected up to July 2, 2021. FINDINGS: Of 64 813 individuals enrolled, 56 261 were included in the final analysis, of whom 33 533 (59·6%) had received at least one dose of the CoronaVac vaccine, 8947 (15·9%) had received at least one dose of the BNT162b2 vaccine, and 13 781 (24·5%) had not received a vaccine. SARS-CoV-2 IgG positivity during week 4 after the first dose of CoronaVac was 28·1% (95% CI 25·0-31·2; 220 of 783 individuals), reaching a peak of 77·4% (75·5-79·3; 1473 of 1902 individuals) during week 3 after the second dose. SARS-CoV-2 IgG positivity during week 4 after the first dose of the BNT162b2 vaccine was 79·4% (75·7-83·1; 367 of 462 individuals), increasing to 96·5% (94·9-98·1; 497 of 515 individuals) during week 3 after the second dose and remaining above 92% until the end of the study. For unvaccinated individuals, IgG seropositivity ranged from 6·0% (4·4-7·6; 49 of 810 individuals) to 18·7% (12·5-24·9; 28 of 150 individuals) during the 5 month period. Regression analyses showed that IgG seropositivity was significantly lower in men than women and in people with diabetes or chronic diseases for CoronaVac vaccine recipients (p<0·0001), and for individuals aged 60 years and older compared with people aged 18-39 years for both vaccines (p<0·0001), 3-16 weeks after the second dose. INTERPRETATION: IgG seropositivity was lower after CoronaVac than after BNT162b2 and declined over time since vaccination for CoronaVac recipients but not BNT162b2 recipients. Prolonged IgG monitoring will allow further evaluation of seropositivity overtime, providing data, in conjunction with effectiveness studies, for possible future re-assessment of vaccination strategies. FUNDING: Instituto Sistemas Complejos de Ingeniería and Ministerio de Salud Chile. TRANSLATION: For the Spanish translation of the abstract see Supplementary Materials section.

Priority setting for mental health research in Chile.

BACKGROUND: Scientific knowledge is a fundamental tool for making informed health policy decisions, but the link between health research and public policy decision-making is often missing. This study aims to identify and prioritize a national set of research gaps in mental health. METHODS: A multi-approach method to identify gaps in knowledge was developed, including (1) document analysis and identification of possible research questions, (2) interviews to Ministry of Health key informants, (3) focus groups with different stakeholders, and (4) a web consultation addressed to academics. The identified gaps were translated to a standardized format of research questions. Criteria for prioritization were extracted from interviews and focus groups. Then, a team of various professionals applied them for scoring each question research. FINDINGS: Fifty-four people participated in the knowledge gaps identification process through an online consultation (n = 23) and focus groups (n = 18). Prioritization criteria identified were: extent of the knowledge gap, size of the objective population, potential benefit, vulnerability, urgency and applicability. 155 research questions were prioritized, of which 44% were related to evaluation of systems and/or health programs, and 26% to evaluation of interventions, including questions related to cost-effectiveness. 30% of the research questions came from the online consultation, and 36% from key informants. Users groups contributed with 10% of total research questions. CONCLUSION: A final priority setting for mental health research was reached, making available for authorities and research agencies a list of 155 research questions ordered by relevance. The experience documented here could serve to other countries interested in developing a similar process.

Impact of intraoperative transesophageal echocardiography during noncardiac surgery.

OBJECTIVE: The purpose of this study was to test if parameters measured by intraoperative transesophageal echocardiography (TEE) could be useful to evaluate the hemodynamic status of high-risk cardiovascular patients and if this information was sufficient to make changes in intraoperative management. DESIGN: Prospective clinical study. SETTING: Single-university hospital. PARTICIPANTS: Ninety-eight patients undergoing noncardiac surgery. INTERVENTIONS: Every patient was assessed with a baseline examination of 2-dimensional, color, pulsed, and continuous Doppler images. Intraoperative changes in any of the evaluated and measured parameters led to a specific change according to the protocol. MEASUREMENTS AND MAIN RESULTS: After continuous monitoring with TEE during surgery, all patients were assigned to 1 of the following groups: (1) TEE was of no use, (2) TEE-directed intraoperative management changes, (3) intraoperative TEE-directed changes in postoperative management, and (4) TEE successfully used as a substitute for pulmonary artery catheter monitoring. Two patients (2%) were assigned to group 1, 47 (48%) patients to group 2, 25 (25%) patients to group 3, and 24 (24%) patients to group 4. The most frequent modifications in intraoperative management were changes in drug therapy and fluid administration. Postoperative management changes were mostly made because of new diagnosis (14%) and new left ventricular wall motion abnormalities (9%). CONCLUSION: These results strongly suggest that objective measurements made by intraoperative TEE are effective in unveiling relevant clinical findings and useful information in high-risk patients undergoing noncardiac surgery.

Presión sistólica de arteria pulmonar: ecocardiografía transesofágica intraoperatoria versus Swan Ganz / Systolic pulmonary artery pressure: intraoperative transesophageal echocardiography versus Swan Ganz

La Ecocardiografía Transesofágica (ETE) ha sido un significativo avance en el conocimiento y manejo de la hemodinamia de los pacientes. La medición de volúmenes con ETE es de alta calidad y permite su manejo ajustado. Sin embargo, en la evaluación hemodinámica global de cada paciente también es necesario conocer las presiones. Por esto es importante validar la medición de presiones que se realizan con ETE contra la técnica estándar de uso en clínica. Así se estudiaron en forma prospectiva 27 pacientes comparándose las mediciones de presión sistólica de arteria pulmonar (PSAP) obtenidas con ETE y catéter de Swan Ganz. Se realizaron un total de 81 pares de mediciones que al correlacionarlas mostraron una r=0,91. Se concluye que esta excelente correlación le confiere a la ETE ventajas como sistema de monitorización de presiones, semiinvasivo y latido a latido frente a la técnica invasiva de catéter de arteria pulmonar. La validación de mediciones de presión con ETE permite conocer en forma exacta y simultánea la relación entre el volumen y la presión que se genera en una determinada cavidad, permitiendo así trabajar en los puntos de la curva de Starling donde estas relaciones para un paciente determinado sean óptimas.

[Intraoperatory hemodynamic monitoring with transesophageal echocardiography]. / Monitorización hemodinámica intraoperatoria con ecocardiografía transesofágica: experiencia clínica.

BACKGROUND: Transesophageal echocardiography allows a semi-invasive hemodynamic monitoring, during cardiac and non cardiac surgery. The benefits of such surveillance must be assessed, since it may help to change patient management. AIM: To assess the usefulness of transesophageal echocardiography during surgical procedures in critical patients. MATERIAL AND METHODS: Based on the indications of the North American Societies of Cardiology and Anesthesiology, 264 patients were monitored using a multiplanar transducer. The type of surgery, insertion difficulties, quality of visualization, complications and usefulness of the method were recorded. RESULTS: One hundred eleven cardiac and 153 non cardiac surgical procedures were monitored. In 97% of cases, visualization was good. In 2 cases, it was impossible to obtain a transgastric axis. No complications of the procedure were recorded. The method was useless in nine patients, helpful to change drug and volume management in 126 (48%) patients, helpful to change perioperative management in 49 (19%) patients and was a substitute for pulmonary artery catheterization in 79 (30%) patients. CONCLUSIONS: Intraoperative transesophageal echocardiography is a safe technique that renders high quality images, with a low incidence of complications and that, when well indicated, orients therapeutic changes in 98% of patients.

Arritmias en anestesia pediátrica / Arrhythmias in pediatric anesthesia

La frecuencia de arritmias en cirugía pediátrica, varía entre un 13% a 84% en distintas series. Considerando la escasa experiencia reportada que existe en nuestro medio acerca de este tema, nos hemos interesado en evaluar la incidencia de arritmias en anestesia pediátrica y analizar algunos de los factores involucrados en la aparición de éstas. Se estudiaron 100 niños de 0 a 12 años, ASA I, sometidos a cirugía electiva con anestesia general (O2,N2O, Halotano). Distinguiendo 2 grupos: A intubados (n57) y B con mascarilla (n43). La incidencia global de arritmias fue de un 23%, siendo en el grupo A 12,3% y en el grupo B 37,2%. Tanto los reflejos derivados de la maniobra quirúrgica, como la superficialidad anestésica deben ser consideradas en la aparición de arritmias en un grupo de nuestros enfermos. La hipoxemia y/o hipercapnia podrían contribuir en la producción de arritmias, especialmente en el grupo con mascarilla. La aparición de trastornos del ritmo puede constituir una señal de alarma frente a alteraciones de la ventilación