Dietary Intake of (Poly)phenols and Risk of All-Cause and Cause-Specific Mortality in the Mexican Teachers' Cohort Study.

BACKGROUND: Observational studies have reported that total (poly)phenol intake is associated with a reduction in all-cause and cardiovascular mortality, but mainly from high-income countries, where (poly)phenol intake may differ from that of low- and middle-income countries. OBJECTIVES: Our objective was to evaluate the association between the intake of total, all classes, and subclasses of (poly)phenols and risk of all-cause and cause-specific mortality in a Mexican cohort. METHODS: We used data from the Mexican Teachers' Cohort, which included 95,313 adult females. After a median follow-up of 11.2 y, 1725 deaths were reported, including 674 from cancer and 282 from cardiovascular diseases. (Poly)phenol intake was estimated using a validated food frequency questionnaire and the Phenol-Explorer database. Multivariable Cox models were applied to estimate the association between (poly)phenol intake and all-cause mortality and competitive risk models for cause-specific mortality. RESULTS: Comparing extreme quartiles, total (poly)phenol intake was associated with lower risk of all-cause [hazard ratio (HR)Q4vs.Q1: 0.88; 95% CI: 0.76, 0.99; P-trend = 0.01] and cancer mortality (HRQ4vs.Q1: 0.81; 95% CI: 0.64, 0.99; P-trend = 0.02). Among (poly)phenol classes, phenolic acids, particularly hydroxycinnamic acids from coffee, showed an inverse association with all-cause (HRQ4vs.Q1: 0.79; 95% CI: 0.69, 0.91; P-trend = 0.002) and cancer mortality (HRQ4vs.Q1: 0.75; 95% CI: 0.61, 0.94; P-trend = 0.03). No associations were observed with flavonoids or with cardiovascular mortality. CONCLUSION: Our study suggests that high (poly)phenol intake, primarily consisting of phenolic acids such as hydroxycinnamic acids, may have a protective effect on overall and cancer mortality. Null associations for flavonoid intake might be due to the potential underestimation of their intake in this population.

Low-intensity daily smoking and mortality risk among Mexican women.

OBJECTIVE: To examine the association between low-intensity smoking (10 or less cigarettes per day) and all-cause and cause-specific mortality risk among women who smoke and by age at cessation among women who previously smoked. METHODS: In this study, 104 717 female participants of the Mexican Teachers' Cohort Study were categorised according to self-reported smoking status at baseline (2006/2008) and were followed for mortality through 2019. We estimated HRs and 95% CIs for all-cause and cause-specific mortality using multivariable Cox proportional hazards regression models with age as the underlying time metric. RESULTS: Smoking as few as one to two cigarettes per day was associated with higher mortality risk for all causes (HR: 1.36; 95% CI 1.10 to 1.67) and all cancers (HR: 1.46; 95% CI 1.05 to 2.02), compared with never smoking. Similarly, slightly higher HRs were observed among participants smoking ≥3 cigarettes per day (all causes HR: 1.43; 95% CI 1.19 to 1.70; all cancers HR: 1.48; 95% CI 1.10 to 1.97; cardiovascular disease HR: 1.58; 95% CI 1.09 to 2.28). CONCLUSIONS: In this large study of Mexican women, low-intensity smoking was associated with higher mortality risk for all causes and all cancers. Interventions are needed to promote cessation among women who smoke at low-intensity in Mexico, regardless of how few cigarettes they smoke per day.

Disparities on prostate cancer survival in Mexico: a retrospective cohort study.

OBJECTIVE: To estimate prostate cancer (PC) survival in Mexico and explore survival disparities according to the marginalization level of residence place. MATERIALS AND METHODS: A nationwide administrative claims database (4 110 men) whose PC treatment was financed by Seguro Popular between 2012-2016, was cross-linked to the National Mortality Registry up to December 2019. Patients were classified according to their oncological risk at diagnosis and the marginalization level of the residence municipality. Cox proportional hazards regression was used to estimate multivariable survival functions. RESULTS: Five-years PC survival (69%; 95%CI: 68,71%) ranged from 72% to 54% at very low and very high marginalization, respectively (p for trend<0.001). The lowest PC survival was observed in men with high-risk PC (47%; 95%CI: 33,66%) residents in very high marginalization municipalities. CONCLUSIONS: Overall, PC survival was lower than that reported in other Latin American countries. The distribution of oncologic risk and survival differences across marginalization levels suggests limited early detection and cancer health disparities.

The Omicron wave in Mexico: vaccine protection against progression to severe Covid-19 in SARS-CoV-2-infected workers.

OBJECTIVE: To assess the effectiveness of seven Covid-19 vaccines in preventing disease progression (DP) using data from national private sector workers during the Omicron wave in Mexico from January 2 to March 5, 2022. MATERIALS AND METHODS: This study employed an administrative retrospective cohort design, analyzing DP (hospitalization or death due to respiratory disease) among workers who filed a respiratory short-term disability claim and tested positive for SARS-CoV-2. Risk ratios (RRadj) were estimated using Poisson regression models adjusted for various factors. RESULTS: Vaccinated individuals had a lower risk of hospitalization and death compared with unvaccinated individuals. The overall RRadj for hospitalization and death were 0.36 (95%CI 0.32, 0.41) and 0.24 (0.17, 0.33), respectively. When evaluating vaccines individually, the RRadj for hospitalization were as follows Pfizer BioNTech 0.27 (95%CI 0.22, 0.33), Moderna 0.29 (95%CI 0.15, 0.57), Sinovac 0.32 (95%CI 0.25, 0.41), AstraZeneca 0.39 (95%CI 0.34, 0.46), Sputnik 0.39 (95%CI 0.28, 0.53), CanSino 0.41 (95%CI 0.24, 0.7), and Janssen 0.53 (95%CI 0.39, 0.72). The RRadj for death were as follows: Pfizer BioNTech 0.12 (95%CI 0.07, 0.19), Sputnik 0.15 (95%CI 0.06, 0.38), Sinovac 0.29 (95%CI 0.16, 0.53), AstraZeneca 0.30 (95%CI 0.20, 0.44), CanSino 0.38 (95%CI 0.1, 1.4), and Janssen 0.50 (95%CI 0.26, 0.97). CONCLUSION: Covid-19 vaccines significantly reduced the risk of severe disease during the Omicron wave in Mexico.

Comparing the usefulness of two mortality registries for data-linkage for prospective cohorts in Mexico.

OBJECTIVE: To estimate the sensitivity and specificity of two Mexican death registries for the identification of vital status using a publicly available record-linkage tool. MATERIALS AND METHODS: We selected all reported deaths (n=581) and 575 alive participants in an epidemiologic cohort with active follow-up. Individual records were cross-linked to two mortal-ity registries. RESULTS: A sensitivity of 87.2% (95%CI: 84.7, 90.2) and specificity of 99.3% (95%CI: 98.2, 99.8) were jointly achieved with both registries. Major discrepancies in cause of death were observed in 10.8% of deaths. CONCLUSION: There is initial evidence that Mexican death registries are a valuable resource for mortality follow-up in epidemiologic studies.

Supervivencia y factores asociados en pacientes con cáncer cervicouterino atendidas por el Seguro Popular en México.

 Objetivo. Estimar la supervivencia a cinco años por cáncer cervicouterino y sus factores asociados en pacientes mexica-nas, cuya atención fue financiada por el Fondo de Protección contra Gastos Catastróficos (FPGC) del Seguro Popular durante el periodo 2006-2014. Material y métodos. Se analizó la base de datos de las pacientes mencionadas y se vinculó con el Subsistema Epidemiológico y Estadístico de Defunciones. Se hizo un análisis de supervivencia a cinco años por etapa clínica y factores asociados, mediante el método de Kaplan-Meier y los modelos de riesgos proporcionales de Cox. Resultados. La supervivencia global por cáncer cervicouterino a los cinco años fue de 68.5%. Los factores asociados fueron la etapa clínica (locoregional [HR=2.8 IC95% HR: 2.6,3.0] y metastásica [HR=5.4 IC95% HR: 4.9,5.9]) com-parada con la etapa temprana y la edad (HR=1.003 IC95% HR:1.001,1.004). Conclusiones. Las mujeres que lograron el acceso a la atención del cáncer cervical financiadas por el FPGC tuvieron una supervivencia ligeramente superior a las reportadas en otros estudios.

Estimación del exceso de mortalidad por todas las causas durante la pandemia del Covid-19 en México.

 Objetivo. Estimar el exceso de defunciones por todas las causas en México durante 2020. Material y métodos. Se construyó un canal endémico con las defunciones (2015- 2019), estableciendo el umbral epidémico en el percentil 90, y se comparó con las actas de defunción para estimar el exceso de mortalidad. Resultados. A la semana 53, ocurrieron 326 612 defunciones en exceso (45.1%), con un máximo en la semana 28 (98.0%) y un mínimo en la semana 41 (35.2%); después de la semana 4 los hombres (51.3%), principalmente de 45-64 años de edad, sin embargo, en los de 60 años o más ocurrió el mayor nú-mero de defunciones. Conclusión. En México, el exceso de mortalidad ha sido prolongado en comparación con otros países, con alta variabilidad interestatal. Esto podría deberse a las condiciones socioeconómicas y a la alta prevalencia de comorbilidades que aumentan el riesgo de morir en la población mexicana.

Evaluation of Mexico's low cancer mortality using two national death registries.

OBJECTIVE: To compare cancer mortality rates in Mexico from two national death registries that independently code and attribute cause of death. MATERIALS AND METHODS: We compared 5-year age-standardized total cancer and sitespecific cancer mortality rates (2010-2014) from Mexico's official death registry with a death registry from a disease surveillance system. We obtained age-adjusted mortality rates and 95% confidence intervals using the direct method and World Population Prospects 2010 as a standard. RESULTS: Cancer mortality estimates for Mexico were minimally affected by the use of two distinct death certificate-coding procedures. Cancer mortality was 73.3 for Instituto Nacional de Estadística y Geografía and 72.7 for System for Epidemiologic Death Statistics per 100 000 women. The corresponding estimates for men were 68.3 and 67.8. CONCLUSIONS: Mexico's low cancer mortality is unlikely to be explained by death certificate processing. Further investigations into the process of death certification and cancer registration should be conducted in Mexico.

OBJETIVO: Comparar la mortalidad por cáncer en México a partir de dos registros de mortalidad nacionales. MATERIAL Y MÉTODOS: Se comparó la tasa de mortalidad estandarizada por edad para cáncer total y por sitio específico (2010-2014) utilizando dos fuentes con diferentes métodos de procesamiento de información. Se obtuvieron tasas estandarizadas e intervalos de confianza al 95% utilizando el método directo y como población estándar el World Population Prospects 2010. RESULTADOS: Las tasas de mortalidad no se vieron afectadas por métodos distintos para procesar información. La mortalidad por cáncer en mujeres fue de 73.3 por cada 100 000 en el Instituto Nacional de Estadística y Geografía y 72.7 en el Subsistema Epidemiológico y Estadístico de Defunciones. Las estimaciones para hombres fueron 68.3 and 67.8, respectivamente. CONCLUSIONES: Es poco probable que la baja mortalidad por cáncer en México se explique por el procesamiento de la información. Es necesario realizar estudios enfocados en el proceso de certificación y registro de muerte por cáncer.

[Vaccination in Mexico: imprecise coverages and deficiency in the follow-up of children with incomplete immunization]. / Vacunación en México: coberturas imprecisas y deficiencia en el seguimiento de los niños que no completan el esquema.

OBJECTIVE: To analyze the validity of the official vaccination figures according to the available information and to identify opportunities for improvement. MATERIALS AND METHODS: We estimated vaccination coverage and dropout rates (for multi-dose vaccines) for one-year-old children, based on public information from the dynamic cubes of the Ministry of Health, for the years 2015 to 2017. R. RESULTS: We observed variations in the vaccination monthly reports, which indicate low rates of vaccination, as well as high dropout rates when comparing first and third doses applied. For children 1 year of age, the national complete coverage was estimated at 48.9. CONCLUSIONS: There is no reliable information to estimate the actual vaccination coverage. Government documents report a constant overestimation of vaccination coverage that creates a "false sense of security". This has become a barrier for the critical analysis of the Universal Vaccination Program.

OBJETIVO: Analizar la veracidad de las cifras oficiales de acuerdo con la información disponible e identificar oportunidades de mejora. MATERIAL Y MÉTODOS: Estimamos las coberturas de vacunación y tasas de deserción (para las vacunas administradas en multidosis) del esquema básico para niños menores de un año de edad, con base en la información de cubos dinámicos de la Secretaría de Salud de 2015 a 2017. RESULTADOS: Observamos variaciones en los reportes mensuales de vacunación que indican bajas tasas de vacunación, así como índices altos de deserción al comparar primeras y terceras dosis aplicadas. La cobertura nacional de esquema completo se estimó en 48.9 por ciento. CONCLUSIONES: No se cuenta con información confiable que permita estimar las coberturas reales de vacunación. En los reportes oficiales hay una constante sobrestimación de las coberturas que ha creado a una "falsa sensación de seguridad". Esto se ha constituido en una barrera que impide el análisis crítico del Programa Universal de Vacunación.

Overview of acute diarrheal disease at the dawn of the 21st century: The case of Mexico.

OBJECTIVE: To provide an overview of morbidity and mortality due to acute diarrheal disease in Mexico in order to understand its magnitude, distribution, and evolution from 2000 to 2016. MATERIALS AND METHODS: We carried out a longitudinal ecological study with secondary sources of information. We used data from epidemiological surveillance, health services, and vital statistics. We calculated and mapped measures of utilization of health services rates and mortality due to diarrheal diseases. RESULTS: Diarrhea morbidity decreased by 42.1% across the period. However, emergency department attendances increased by 50.7% in the Ministry of Health. The hospitalization rate and mortality among the general population decreased by 37.6 and 39.7%, respectively, and the infant mortality rate decreased by 72.3% among children under five years of age. Chiapas and Oaxaca had the highest mortality among the states of Mexico. CONCLUSIONS: Cases of diarrhea, including rotavirus, have decreased in Mexico. However, in 2016, 3.4 per 100 000 people died due to diarrhea, which could have been avoided with health promotion.

OBJETIVO: Ofrecer un panorama de la morbimortalidad por enfermedad diarreica aguda (EDA) entre 2000 y 2016 en México, para entender su magnitud, distribución y evolución. MATERIAL Y MÉTODOS: Estudio ecológico longitudinal, con fuentes de información secundarias. Se analizaron datos de vigilancia epidemiológica, prestación de servicios y estadísticas vitales. Se calcularon tasas de utilización de servicios y mortalidad. RESULTADOS: La morbilidad por EDA disminuyó 42.1% en el periodo, sin embargo, la atención por urgencias aumentó 50.7% en SS. La tasa de hospitalización descendió 37.6% y la mortalidad 39.7% en población general y 72.3% en menores de cinco años. Chiapas y Oaxaca fueron los estados con mayor tasa de mortalidad. CONCLUSIONES: Los casos de diarrea, incluyendo los de rotavirus, han disminuido en el país. Sin embargo, en 2016 se encontró una tasa de 3.4 por 100 000 personas que mueren por EDA, lo cual podría evitarse con promoción de la salud.

Zika virus infection estimates, Mexico.

OBJECTIVE: To assess the magnitude of the Mexican epidemic of Zika virus infection and the associated risk of microcephaly. METHODS: From the reported number of laboratory-confirmed symptomatic infections among pregnant women and the relevant birth rate, we estimated the number of symptomatic cases of infection that occurred in Mexico between 25 November 2015, when the first confirmed Mexican case was reported, and 20 August 2016. We used data from the birth certificates to compare mean monthly incidences of congenital microcephaly before (1 January 2010-30 November 2015) and after (1 December 2015-30 September 2017) the introduction of Zika virus, stratifying the data according to whether the mother's place of residence was at an altitude of at least 2200 m above sea level. We used Poisson interrupted time series, statistical modelling and graphical analyses. FINDINGS: Our estimated number of symptomatic cases of infection that may have occurred in the general population of Mexico between 25 November 2015 and 20 August 2016, 60 172, was 7.3-fold higher than the corresponding number of reported cases. The monthly numbers of microcephaly cases per 100 000 live births were significantly higher after the introduction of the virus than before (incidence rate ratio, IRR: 2.9; 95% confidence interval, CI: 2.3 to 3.6), especially among the babies of women living at altitudes below 2200 m (IRR: 3.4; 95% CI: 2.9 to 3.9). CONCLUSION: The Mexican epidemic appears to be much larger than indicated by estimates based solely on counts of laboratory-confirmed cases, and to be associated with significantly increased risk of microcephaly.

Effect of care-delivery delay on the survival of Mexican women with breast cancer.

OBJECTIVE: To estimate the effect of care-delivery delays on survival among women with breast cancer. MATERIALS AND METHODS: A retrospective analysis of 854 women attending 11 hospitals from 2007-2009 was carried out. Kaplan-Meier estimators and a Cox proportional-risk model were employed. RESULTS: A total of 10.5% of cases were diagnosed in stage I. 82% of sampled women delayed care for more than 67 days between noticing a symptom and initiating treatment. The median time from receipt of results of the mammography to biopsy was 31 days (IQR 14-56). Compared with those who were in quartile I (Q1), survival was lower among those in Q3 and Q4 (HR=1.68, 95%CI 0.94-3.00; HR=1.76, 95% CI 1.04-2.98, respectively). CONCLUSIONS: To increase survival, it is suggested that the time between receipt of the mammography results and diagnostic biopsy be reduced.

Utilization of hospital services for cancer care in Mexico.

OBJECTIVE: To analyze the utilization of hospital services for cancer care by location, sex, age group and care institution in Mexico from 2004-2013. MATERIALS AND METHODS: Time series study from 2004-2013, based on administrative records of hospital discharges for cancer in the health sector, including the private sector. RESULTS: The utilization rate increased significantly from 290 to 360 per 100 000 inhabitants. A total of 62% of hospital discharges related to malignant tumors were concentrated in eight types of cancer. Leukemia, breast and colorectal cancers almost doubled in the period. While lung cancer showed a decline among men, it increased among women. A total of 63.1% of cancer patients were women, and 81% of cases occurred in the public sector. From 2011, the Ministry of Health was the main provider of hospital services for cancer care. CONCLUSIONS: Increases in utilization were mainly found in the Ministry of Health, quite possibly as a result of the implementation of universal insurance.

[Analysis of the evidence on the efficacy and safety of CYD-TDV dengue vaccine and its potential licensing and implementation through Mexico's Universal Vaccination Program]. / Análisis de la evidencia sobre eficacia y seguridad de la vacuna de dengue CYD-TDV y su potencial registro e implementación en el Programa de Vacunación Universal de México.

Dengue is a major global public health problem affecting Latin America and Mexico Prevention and control measures, focusing on epidemiological surveillance and vector control, have been partially effective and costly, thus, the development of a vaccine against dengue has created great expectations among health authorities and scientific communities worldwide. The CYD-TDV dengue vaccine produced by Sanofi-Pasteur is the only dengue vaccine evaluated in phase 3 controlled clinical trials. Notwithstanding the significant contribution to the development of a vaccine against dengue, the three phase 3 clinical studies of CYD-TDV and the meta-analysis of the long-term follow up of those studies, have provided evidence that this vaccine exhibited partial vaccine efficacy to protect against virologically confirmed dengue and lead to four considerations: a) adequate vaccine efficacy against dengue virus (DENV) infections 3 and 4, less vaccine efficacy against DENV 1 and no protection against infection by DENV 2; b) decreased vaccine efficacy in dengue seronegative individuals at the beginning of the vaccination; c) 83% and 90% protection against hospitalizations and severe forms of dengue, respectively, at 25 months follow-up; and d) increased hospitalization for dengue in the vaccinated group, in children under nine years of age at the time of vaccination, detected since the third year of follow-up. The benefit of the CYD-TDV vaccine can be summarized in the protection against infection by DENV 3 and 4, as well as protection for hospitalizations and severe cases in people over nine years, who have had previous dengue infection, working mainly as a booster. In this review we identified elements on efficacy and safety of this vaccine that must be taken into account in the licensing process and potential inclusion in the national vaccination program of Mexico. The available scientific evidence on the CYD-TDV vaccine shows merits, but also leads to relevant questions that should be answered to properly assess the safety profile of the product and the target populations of potential benefit. In this regard we consider it would be informative to complete the 6-year follow-up after starting vaccination, according to the company's own study protocol recommended by the World Health Organization. As with any new vaccine, the potential licensing and implementation of the CYD-TDV as part of Mexico's vaccination program, requires a clear definition of the balance between the expected benefits and risks. Particularly with a vaccine with variable efficacy and some signs of risk, in the probable case of licensing, the post-licensed period must involve the development of detailed protocols to immediately identify risks or any health event associated with vaccination.

Breast cancer survival in Mexico between 2007 and 2016 in women without social security: a retrospective cohort study.

Background: Essential indicators of health system performance for breast cancer are lacking in Mexico. We estimated survival and clinical stage distribution for women without social insurance who were treated under a health financing scheme that covered 60% of the Mexican population. Methods: We conducted a retrospective cohort study cross-linking reimbursement claims for 56,847 women treated for breast cancer between 2007 and 2016 to a mortality registry. We estimated overall- and clinical stage-specific survival and breast cancer survival according to patient age, state of residence, marginalization, type of treatment facility, and patient volume of the treatment facility. We also explored the distribution of clinical stage according to age, year of treatment initiation, and state where the woman was treated. We used log-rank tests and estimated 95% CIs to compare differences between patient groups. Findings: Median age was 52 years (interquartile range [IQR] 45, 61) (Sixty five percent patients (36,731/56,847) had advanced disease at treatment initiation. Five-year overall survival was 72.2% (95% CI 71.7, 72.6). For early disease (excluding stage 0), 5-year overall survival was 89.0% (95% CI 88.4, 89.5), for locally advanced disease 69.9% (95% CI 69.0, 70.2) and for metastatic 36.9% (95% CI 35.4, 38.4). Clinical stage at treatment initiation and breast cancer survival remained unchanged in the period analyzed. Clinical stage and survival differed across age groups, state of residence, and type of facility where women received treatment. Interpretation: In the absence of population-based cancer registries, medical claims data may be efficiently leveraged to estimate essential cancer-related performance indicators. Funding: The authors received no financial support for this research.

Cervical cancer prevention program in Mexico disrupted due to COVID-19 pandemic: Challenges and opportunities.

Introduction: The COVID-19 pandemic disrupted the preventive services for cervical cancer (CC) control programs in Mexico, which will result in increased mortality. This study aims to assess the impact of the pandemic on the interruption of three preventive actions in the CC prevention program in Mexico. Methods: This study is a retrospective time series analysis based on administrative records for the uninsured population served by the Mexican Ministry of Health. Patient data were retrieved from the outpatient service information system and the hospital discharge database for the period 2017-2021. Data were aggregated by month, distinguishing a pre-pandemic and a pandemic period, considering April 2020 as the start date of the pandemic. A Poisson time series analysis was used to model seasonal and secular trends. Five process indicators were selected to assess the disruption of the CC program, these were analyzed as monthly data (N=39 pre-pandemic, N=21 during the pandemic). HPV vaccination indicators (number of doses and coverage) and diagnostic characteristics of CC cases were analyzed descriptively. The time elapsed between diagnosis and treatment initiation in CC cases was modeled using restricted cubic splines from robust regression. Results: Annual HPV vaccination coverage declined dramatically after 2019 and was almost null in 2021. The number of positive Papanicolaou smears decreased by 67.8% (90%CI: -72.3, -61.7) in April-December 2020, compared to their expected values without the pandemic. The immediate pandemic shock (April 2020) in the number of first-time and recurrent colposcopies was -80.5% (95%CI:-83.5, -77.0) and -77.9% (95%CI: -81.0, -74.4), respectively. An increasing trend was observed in the proportion of advanced stage and metastatic CC cases. The fraction of CC cases that did not receive medical treatment or surgery increased, as well as CC cases that received late treatment after diagnosis. Conclusions: Our analyses show significant impact of the COVID-19 pandemic with declines at all levels of CC prevention and increasing inequalities. The restarting of the preventive programs against CC in Mexico offers an opportunity to put in place actions to reduce the disparities in the burden of disease between socioeconomic levels.

Implementation and validation of a probabilistic linkage method for population databases without identification variables.

Linking records of the same person from different sources makes it possible to build administrative cohorts and perform longitudinal analyzes, as an alternative to traditional cohort studies, and have important practical implications in producing knowledge in public health. We implemented the Fellegi-Sunter probabilistic linkage method to a sample of records from the Mexican Automated System for Hospital Discharges and the Statistical and Epidemiological System for Deaths and evaluated its performance. The records in each source were randomly divided into a training sample (25%) and a validation sample (75%). We evaluated different types of blocking in terms of complexity reduction and pairs completeness, and record linkage in terms of sensitivity and positive predictive value. In the validation sample, a blocking scheme based on trigrams of the full name achieved 95.76% pairs completeness and 99.9996% complexity reduction. After pairs classification, we achieved a sensitivity of 90.72% and a positive predictive value of 97.10% in the validation sample. Both values were about one percentage point higher than that obtained in the automatic classification without clerical review of potential pairs. We concluded that the linkage algorithm achieved a good performance in terms of sensitivity and positive predictive value and can be used to build administrative cohorts for the epidemiological analysis of populations with records in health information systems.

Leading causes of excess mortality in Mexico during the COVID-19 pandemic 2020-2021: A death certificates study in a middle-income country.

Background: The death toll after SARS-CoV-2 emergence includes deaths directly or indirectly associated with COVID-19. Mexico reported 325,415 excess deaths, 34.4% of them not directly related to COVID-19 in 2020. In this work, we aimed to analyse temporal changes in the distribution of the leading causes of mortality produced by COVID-19 pandemic in Mexico to understand excess mortality not directly related to the virus infection. Methods: We did a longitudinal retrospective study of the leading causes of mortality and their variation with respect to cause-specific expected deaths in Mexico from January 2020 through December 2021 using death certificate information. We fitted a Poisson regression model to predict cause-specific mortality during the pandemic period, based on the 2015-2019 registered mortality. We estimated excess deaths as a weekly difference between expected and observed deaths and added up for the entire period. We expressed all-cause and cause-specific excess mortality as a percentage change with respect to predicted deaths by our model. Findings: COVID-19 was the leading cause of death in 2020-2021 (439,582 deaths). All-cause total excess mortality was 600,590 deaths (38⋅2% [95% CI: 36·0 to 40·4] over expected). The largest increases in cause-specific mortality, occurred in diabetes (36·8% over expected), respiratory infections (33·3%), ischaemic heart diseases (32·5%) and hypertensive diseases (25·0%). The cause-groups that experienced significant decreases with respect to the expected pre-pandemic mortality were infectious and parasitic diseases (-20·8%), skin diseases (-17·5%), non-traffic related accidents (-16·7%) and malignant neoplasm (-5·3%). Interpretation: Mortality from COVID-19 became the first cause of death in 2020-2021, the increase in other causes of death may be explained by changes in the health service utilization patterns caused by hospital conversion or fear of the population using them. Cause-misclassification cannot be ruled out. Funding: This study was funded by Conacyt.

[Health information systems in the Mesoamerican Region]. / Sistemas de información en salud en la Región Mesoamericana.

OBJECTIVE: To evaluate and analyze health information systems (his) in the Mesoamerican Region. MATERIAL AND METHODS: The conceptual framework and tools of the Health Metrics Network (nhm) was used. It measures six components of the his assessment: resources, indicators, data sources, information management, products and use. RESULTS: In this study we found that the average score of the HIS in the Mesoamerican region was 57%, being the maximum value for Mexico (75%) and the minimum for El Salvador (41%). The item that had lowest scores was that referring to the Management and Administration, where the average assessment was 37%, placing it as present but not adequate. The component with the highest score was Information Products with more than 69%, adequate. In any case, no items were very adequate. CONCLUSION: The performance of his is heterogeneous between countries. It is necessary to strengthen and standardize the criteria of the his in the region, so that these are integrated and used in the decision making process based on real information.