Serviços Partilhados do Ministério da Saúde

Through deterministic data linkage of health registries, mRNA vaccine effectiveness (VE) against COVID-19-related hospitalisations and deaths was measured in 1,880,351 older adults. VE against hospitalisations was 94% (95% confidence interval (CI): 88-97) and 82% (95% CI: 72-89) for those 65-79 and ≥ 80 years old, with no evidence of waning 98 days after dose two. VE against mortality was 96% (95% CI: 92-98) and 81% (95% CI: 74-87) in these two age groups.

BACKGROUND: This paper aims to discuss how physical activity (PA) brief assessment, brief counseling, and self-monitoring tools were designed and implemented in the Portuguese National Health Service (NHS), and to report on their current use by health professionals and citizens. METHODS: Three digital tools to facilitate PA promotion in primary health care (PHC) were developed: 1) a PA brief assessment tool was incorporated in the electronic health record platform "SClínico Cuidados de Saúde Primários"; 2) a brief counseling tool was developed in the software "PEM-Prescrição Eletrónica Médica" (electronic medical prescription); and 3) a "Physical Activity Card" was incorporated in an official NHS smartphone app called "MySNS Carteira". RESULTS: From September 2017 to June 2019, 119,386 Portuguese patients had their PA assessed in PHC. Between December 2017 and June 2019, a total of 7957 patients received brief intervention for PA by a medical doctor. Regarding the app "MySNS Carteira", 93,320 users activated the "Physical Activity Card", between February 2018 and December 2018. CONCLUSIONS: These tools represent key actions to promote PA among Portuguese citizens using PHC as a priority setting. Further initiatives will follow, including proper assessment of their clinical impact and training programs for health care professionals on PA promotion.

We measured vaccine effectiveness (VE) against COVID-19-related severe outcomes in elderly people in Portugal between May and July 2022. In ≥ 80 year-olds, the second booster dose VE was 81% (95% CI: 75-85) and 82% (95% CI: 77-85), respectively, against COVID-19-related hospitalisation and death. The first booster dose VE was 63% (95% CI: 55-70) in ≥ 80 year-olds and 74% (95% CI: 66-80) in 60-79 year-olds against hospitalisation, and 63% (95% CI: 57-69) and 65% (95% CI: 54-74) against death.

Abstract Introduction Early reports showed that Omicron (BA.1) SARS-CoV-2 could be less severe. However, the magnitude of risk reduction of hospitalization and mortality of Omicron (BA.1) infections compared with Delta (B.1.617.2) is not yet clear. This study compares the risk of severe disease among patients infected with the Omicron (BA.1) variant with patients infected with Delta (B.1.617.2) variant in Portugal. Methods We conducted a cohort study in individuals diagnosed with SARS-CoV-2 infection between 1 st and 29 th December 2021. Cases were individuals with a positive PCR test notified to the national surveillance system. SARS-CoV-2 variants were classified first by whole genomic sequencing (WGS) and, if this information was unavailable, by detecting the S gene target failure. We considered a hospitalization for all the patients admitted within the 14 days after the SARS-CoV-2 infection; after that period, they were censored. The comparison of the risk of hospitalization between Omicron (BA.1) and Delta (B.1.617.2) VOC was estimated using a Cox proportional hazards model. The mean length of stay was compared using linear regression, and the risk of death between Omicron and Delta patients was estimated with a penalized logistic regression. All models were adjusted for sex, age, previous infection, and vaccination status. Results We included 15 978 participants aged 16 or more years old, 9 397 infected by Delta (B.1.617.2) and 6 581 infected with Omicron (BA.1). Within the Delta (B.1.617.2) group, 148 (1.6%) were hospitalized, and 16 (0.2%) were with the Omicron (BA.1). A total of 26 deaths were reported, all in participants with Delta (B.1.617.2) infection. Adjusted HR for hospitalization for the Omicron (BA.1) variant compared with Delta (B.1.617.2) was 0.25 (95%CI 0.15 to 0.43). The length of stay in hospital for Omicron (BA.1) patients was significantly shorter than for Delta (confounding-adjusted difference -4.0 days (95%CI -7.2 to -0.8). The odds of death were 0.14 (95% CI 0.0011 to 1.12), representing a reduction in the risk of death of 86% when infected with Omicron (BA.1) compared with Delta (B.1.617.2). Conclusion Omicron (BA.1) was associated with a 75% risk reduction of hospitalization compared with Delta (B.1.617.2) and reduced length of hospital stay.

BACKGROUND: Using data from electronic health registries, this study intended to estimate the COVID-19 vaccine effectiveness (VE) in the population aged 65 years and more, against symptomatic infection, COVID-19-related hospitalizations, and deaths, overall and by time since complete vaccination for the period February to September 2021. METHODS: We established a cohort of individuals aged 65 and more years old, resident in Portugal mainland, using the National Health Service User number to link eight electronic health registries. Outcomes included were symptomatic SARS-CoV-2 infections, COVID-19-related hospitalizations or deaths. The exposures of interest were the mRNA vaccines (Comirnaty or Spikevax) and the viral vector (Vaxzevria) vaccine. Complete schedule VE was estimated as one minus the confounder adjusted hazard ratio, for each outcome, estimated by time-dependent Cox regression with time-dependent vaccine exposure. RESULTS: For the cohort of individuals aged 65-79 years, complete scheme VE against symptomatic infection varied 43 (95%CI: 37-49) (Vaxzevria) and 65 (95%CI: 62-68) (mRNA vaccines). This estimate was slightly lower in the ≥80 years cohort (53, 95%CI: 45-60) for mRNA vaccines). VE against COVID-19 hospitalization varied between 89% (95%CI: 52-94) for Vaxzevria and 95% (95%CI: 93-97) for mRNA vaccines for the cohort aged 65-79 years and was 76% (95%CI: 67-83) for mRNA vaccines in the ≥80 years cohort. High VE against COVID-19-related deaths was estimated, for both vaccine types, 95% and 81 (95%CI:76-86) for the 65-79 years and the ≥80 years cohort, respectively. We observed a significant waning of VE against symptomatic infection, with VE estimates reaching approximately 34% for both vaccine types and cohorts. Significant waning was observed for the COVID-19 hospitalizations in the ≥80 years cohort (decay from 83% (95%CI:68 to 91) 14-41 days to 63% (95%CI:37 to 78) 124 days after mRNA second dose). No significant waning effect was observed for COVID-19-related deaths in the period of follow-up of either cohort. CONCLUSIONS: In a population with a high risk of SARS-CoV-2 complications, we observed higher overall VE estimates against more severe outcomes for both age cohorts when compared to symptomatic infections. Considering the analysis of VE according to time since complete vaccination, the results showed a waning effect for both age cohorts in symptomatic infection and COVID-19 hospitalization for the 80 and more years cohort.

Electronic prescription has proved to play an important role in patient safety, quality of care as well as cost control. Electronic Medication Prescription (PEM in Portugal), is a service developed by a Portuguese government institution – SPMS EPE –, to implement the electronic process of prescription, dispensing and reimbursement of ambulatory medication, but it originally implements additional safety and control in the medication circuit, as well as increases the potential to avoid fraud and to reduce costs. The prescription process implements the recent Portuguese law introducing prescription by International Common Denomination. It also introduces features which improve the quality of the prescribing process and increase the safety of the patient. It access to chronic medicines, prescription history and alerts for interaction with allergies and adverse reactions registered on a nationwide electronic health records and conveyed to the national patient summary. Prescriptions are also integrated into the electronic patient records within health care institutions, keeping them updated and relevant. Access to prescription by pharmacy is permitted, only when authorized by the patient, through his electronic personal/citizen identification card, (i.e. with a chip), and prescription code. The dispensing process verifies the accuracy of medication and also the costing to the government, validating the process as prescription information is accessed. This is a major difference to other electronic prescription services.

The nature and the purpose of the ECRIN Data Centre Certification Programme are summarised, and a very brief description is given of the underlying standards (129 in total, divided into 19 separate lists). The certification activity performed so far is described. In a pilot phase 2 centres were certified in 2012. Calls in 2014 and 2015 resulted in a further 8 certified centres, with 2 certifications still in progress, and the 2016 call has generated several additional applications. The impact and benefits of the programme are listed, divided into a) the effects of the introduction of the standards, b) the effects of the certification programme in general, and c) the effects of the certification programme on individual units. The discussion emphasises the generally positive impact of the programme so far but stresses the need to better clarify the perspective and role of the programme.

Containerized service is currently a widely adopted solution to deploy services in the cloud. However, many companies offer a very diverse set of Web accessible services that are subjected to very distinctive workloads. Consequently, to correctly provision the right amount of resources for each of these services is a challenge. In this paper we propose the Autonomic ConTainerized Service Scaler (ACTS), an autonomic system able to horizontally and vertically scale a set of heterogeneous containerized services subjected to different workloads. The adaptation decisions depended on a set of high-level Quality of Experience (QoE) metrics centered on the services' end-user. We have applied ACTS to some of the digital services of the Shared Services of the Ministry of Health (SPMS) public company. The experimental results show that our solution is able to adequately adapt the configuration of each service, as a direct response to alterations on its workload.

SNS24, the Portuguese National Health Contact Center, is a telephone and digital public service that provides clinical services. SNS24 plays an important role in the identification of users’ clinical situations according to their symptoms. Currently, there are a number of possible clinical algorithms defined, and selecting the appropriate clinical algorithm is very important in each telephone triage episode. Decreasing the duration of the phone calls and allowing a faster interaction between citizens and SNS24 service can further improve the performance of the telephone triage service. In this paper, we present a study using deep learning approaches to build classification models, aiming to support the nurses with the clinical algorithm’s choice. Three different deep learning architectures, namely convolutional neural network (CNN), recurrent neural network (RNN), and transformers-based approaches are applied across a total number of 269,654 call records belonging to 51 classes. The CNN, RNN, and transformers-based model each achieve an accuracy of 76.56%, 75.88%, and 78.15% over the test set in the preliminary experiments. Models using the transformers-based architecture are further fine-tuned, achieving an accuracy of 79.67% with Adam and 79.72% with SGD after learning rate fine-tuning; an accuracy of 79.96% with Adam and 79.76% with SGD after epochs fine-tuning; an accuracy of 80.57% with Adam after the batch size fine-tuning. Analysis of similar clinical symptoms is carried out using the fine-tuned neural network model. Comparisons are done over the labels predicted by the neural network model, the support vector machines model, and the original labels from SNS24. These results suggest that using deep learning is an effective and promising approach to aid the clinical triage of the SNS24 phone call services.

INTRODUCTION: Nowadays, Portuguese birth rate is insufficient to ensure renewal of generations. Women high education levels and labor market integration and increased economic difficulties are some of multiple factors leading to a delay in average parenting age and an increase of infertility; also subject to others such as obesity, smoking and alcohol consumption. MATERIAL AND METHODS: Transversal epidemiological study, analytical, uncontrolled, from self-filled online questionnaires, promoted by students' university unions. A sample of 3585 university students was considered and a global and by gender statistic analysis was done through SPSS, Excel was used to build graphics and tables and ArcMap to represent maps. RESULTS: Mainly students from the Health Sciences (40.6%), Universidade de Lisboa (59.4%), female (76.9%), median age of 22; intention to marry/ union 71.0%, parenthood 85.7%. A total of 18.4% smoke, 22.3% consume alcohol and obesity 15.4%; employment (47.4%) and the partner's will (39.9%) were important determinants for parenthood decision as well as having financial stability to provide a good education (33.6%) and healthcare (38.6%); A total of 53.6% have considered the hypothesis of infertility and highlight above 35 year old maternal age (18.7%), obesity (18%) and female smoking (19.0) as factors. Higher and more significant values for smoking (p = 0.001) and alcohol consumption (p = 0.000) in males were found. DISCUSSION: The sample seems representative, well distributed among different areas of study, with more female respondents than the university portuguese ratio. There are more students with parenting projects than marriage/cohabitation, in accordance with Portuguese data. Nevertheless, the same students identify the family as a priority in comparison with employment and career. Parenting decisions are tied by social-economic situation but an important factor is the low fertility due to the maternal age delay of the first pregnancy. CONCLUSION: University student unions are an excellent instrument to access them; a high number of respondents consider having children but delay the decision; there is a lack of information about the consequences of delaying parenting age and about infertility factors. The negative trend of fertility must be seen as a necessity to develop specific policies.

INTRODUCTION: Syndromic surveillance allows early detection of changes in the population's morbidity pattern. The aim of this study is to evaluate the usefulness of indicators related to access to healthcare services, in COVID-19 surveillance. MATERIAL AND METHODS: A time series analysis was performed using the weekly incidence rate of COVID-19 in Mainland Portugal, between weeks 14/2020 (March 30 to April 5) and 25/2020 (June 15 to 21), and six indicators: 1) COVID-19 consultations in primary healthcare; 2) number of COVID-19 emergency department visits; 3) number of emergency department visits due to viral pneumonia; 4) number of hospitalizations due to viral pneumonia; 5) proportion of emergency department visits due to viral pneumonia; and 6) proportion of hospitalizations for viral pneumonia. Pearson correlation and cross-correlations were computed. RESULTS: A strong correlation was found between the weekly incidence rate of COVID-19 and all indicators. [(1) 0.76; (2) 0.82; (3) 0.77; (4) 0.84; (5) 0.86; e (6) 0.90]. Emergency department visits and hospitalizations for viral pneumonia detect variations in the frequency of the disease with a one week lag compared to the incidence rate of COVID-19, in one week. COVID-19 consultations in primary healthcare and emergency department visits trail behind the incidence rate of COVID-19, in one week. The proportion of viral pneumonias in emergency department visits, or hospitalizations, is temporally aligned with the weekly incidence rate of COVID-19. DISCUSSION: The delay found in the COVID-19 primary healthcare consultations and emergency department visits, may be related to changes in access to healthcare services and clinical coding. Emergency department visits and hospitalizations for viral pneumonia may be useful in the early detection of COVID-19. Viral pneumonia may have been coded as being of unknown origin. Future monitoring of these indicators is necessary to ascertain whether the incidence of COVID-19 is significantly influenced by changes in testing strategies. The indicators described in this study will be an asset for the optimization of testing strategies, allocation of healthcare resources to the communities that are most vulnerable to severe morbidity and assessing vaccination impact. As such, surveillance systems based on clinical data will be a valuable complementary tool to SINAVE. CONCLUSION: The indicators under analysis could be used regularly, with special attention to viral pneumonias, to detect outbreaks of COVID-19. Information on pneumonia of unknown etiology may be considered in the surveillance of COVID-19.

Abstract In Portugal, a bivalent COVID-19 vaccine booster was recommended for those with complete primary COVID-19 vaccination, starting on September 6 2022. This study aims to estimate the mRNA bivalent vaccine effectiveness (VE) against COVID-19 infection, hospitalisation and death in the Portuguese population aged 65 and more years with a follow-up of more than six months. Methods We used a cohort approach to analyse six electronic health registries using deterministic linkage. The follow-up period comprehend September 2022 to May 2023. The outcomes included SARS-CoV-2 infection, COVID-19-related hospitalisation and death. Individuals were considered vaccinated 14 days following a bivalent mRNA COVID-19 vaccine uptake. For each outcome, COVID-19 bivalent VE was estimated as one minus the confounder adjusted hazard ratio of bivalent vaccine vs no bivalent vaccine, estimated by Cox regression with time-dependent vaccine exposure. Results In the ≥ 80 year-olds, bivalent VE was 23.2 (95%CI: 20.1 to 26.2), 41.3 (95%CI: 34.5 to 47.5) and 50.3 (44.6 to 55.3), against infection, COVID-19-related hospitalisation and death, respectively. In the 65-79 year-old, bivalent VE against infection was 37.7 (35.5 to 39.8), 58.5 (95%CI: 51.9 to 64.2) against hospitalisation and 65.1 (95%CI: 59 to 70.4) against death. Vaccine effectiveness decay was observed for both age groups and in all outcomes, up to 6 months of vaccine uptake. Conclusions In a population with a high risk of SARS-CoV-2 complications, we observed moderate bivalent VE estimates against severe COVID-19 and low protection against infection. The lower VE estimates observed in the ≥ 80 year-olds should be interpreted in light of the reference group used for the estimation, i.e., individuals with high vaccine coverage (both primary series and multiple boosters). Significant VE decay was observed up to six months of vaccine uptake, which should be considered when preparing future vaccination campaigns.

Anaphylaxis has a growing incidence, especially in children. It represents a medical emergency and its successful therapy depends on early and proper intervention. Intramuscular epinephrine, with dose adjustment according to weight and age, is the drug of choice for anaphylaxis treatment. After resolution of the acute reaction, the patient should be kept under clinical surveillance for 6 to 24 hours, due to possible biphasic reactions. Prescription of an epinephrine auto injectable device should be considered in all patients with diagnosed or suspected anaphylaxis; additionally these patients should always be referred to an Immunoallergy consultation, to perform adequate investigation and management in order to reduce future risk. All anaphylaxis episodes must be recorded in The Portuguese Catalogue of Allergies and other Adverse Reactions (Catálogo Português de Alergias e outras Reações Adversas, CPARA), which represents a fundamental tool to share clinical information within the Health System. The present manuscript intends to disclose the most recent Portuguese guidelines for the diagnosis and treatment of anaphylaxis, making its clinical approach more effective and homogeneous, and to promote the use of The Portuguese Catalogue of Allergies and other Adverse Reactions as an essential tool to register and share information on anaphylaxis in Portugal.

This contribution explores the complex intersection between Artificial Intelligence (AI) and human rights, highlighting the challenges and opportunities that arise as AI becomes increasingly prevalent in society. Beginning with a reference to the Universal Declaration of Human Rights (UDHR) of 1948 and its legal ramifications, the paper delves into how AI emulates human intelligence, impacting people’s lives and rights. The debate surrounding the need to adapt human rights protection laws to technological innovations is examined, with some authors advocating for legal changes, while others argue for an evolution of existing legislation. The literature review details various legal and ethical concerns related to AI, such as algorithmic transparency, discrimination, cybersecurity, privacy, and accountability. The contribution underscores the complex relationship between AI and human rights, identifying significant challenges that require careful analysis. This contribution seeks to contribute to the understanding of these evolving issues, emphasizing that the discussion is still in the exploratory stages in an increasingly technology-driven world intersecting with human rights.

Abstract Background Using data from electronic health registries, this study intended to estimate the COVID-19 vaccine effectiveness in the population aged 65 years and more, against symptomatic infection, COVID-19 related hospitalizations and deaths, overall and by time since complete vaccination. Methods We stablished a cohort of individuals aged 65 and more years old, resident in Portugal mainland, using the National Health Service unique identifier User number to link eight electronic health registries. Outcomes included were symptomatic SARS-CoV-2 infections, COVID-19 related hospitalizations or deaths. The exposures of interest were the mRNA vaccines (Cominarty or Spikevax) and the viral vector Vaxzevria vaccine. Complete scheme vaccine effectiveness (VE) was estimated as one minus the confounder adjusted hazard ratio, for each outcome, estimated by time-dependent Cox regression with time dependent vaccine exposure. Results For the cohort of individuals aged 65-79 years, complete scheme VE against symptomatic infection varied between 43% (Vaxzevria) and 65% (mRNA vaccines). This estimate was slightly lower in the ≥80 year cohort (53% for mRNA vaccines. VE against COVID-19 hospitalization varied between 89% (95%CI: 52-94) for Vaxzevria and 95% (95%CI: 93-97) for mRNA vaccines for the cohort aged 65-79 years and was 76% (95%CI: 67-83) for mRNA vaccines in the ≥80 year cohort. High VE against COVID-19 related deaths were estimated, for both vaccine types, 95% and 81% for the 65-79 years and the ≥80 year cohort, respectively. We observed a significant waning of VE against symptomatic infection, with VE estimates reaching approximately 34% for both vaccine types and cohorts. Significant waning was observed for the COVID-19 hospitalizations in the ≥80 year cohort (decay from 83% 14-41 days to 63% 124 days after mRNA second dose). No significant waning effect was observed for COVID-19 related deaths in the period of follow-up of either cohorts. Conclusions In a population with a high risk of SARS-CoV-2 complications, we observed higher overall VE estimates against more severe outcomes for both age cohorts when compared to symptomatic infections. Considering the analysis of VE according to time since complete vaccination, the results showed a waning effect for both age cohorts in symptomatic infection and COVID-19 hospitalization for the 80 and more yo cohort.

INTRODUCTION: Portugal presents the highest incidence of stage 5 chronic kidney disease in Europe. It is speculated that a high consumption of non-steroidal anti-inflammatory drugs (NSAIDS) may contribute to this high incidence. Our aim was to characterize the prescription of non-steroidal anti-inflammatory drugs to patients with diabetes mellitus in Portugal. MATERIAL AND METHODS: We analyzed the national prescription database in triennium 2015 - 2017. In patients with diabetes mellitus, we evaluated the prescription of non-steroidal anti-inflammatory drugs according to age, gender and region of the patient and specialty of the prescribing physician. We evaluated the prescription of non-steroidal anti-inflammatory drugs in all patients with diabetes mellitus, in patients with presumed renal impairment, and in those with concomitant prescription of angiotensin converting enzyme inhibitors or angiotensin receptor antagonists. RESULTS: We analyzed 23 320 620 prescriptions, corresponding to 610 157 adults, including 104 306 patients with diabetes mellitus. The most prescribed non-steroidal anti-inflammatory drugs were ibuprofen (20.1%), metamizole (14.7%), and diclofenac (11.4%). The prescription of non-steroidal anti-inflammatory drugs was higher in females, in patients aged 51 - 70 years and in the Alentejo region. Non-steroidal anti-inflammatory drugs were prescribed to 70.6% of patients with diabetes mellitus, from which 10.6% were prescribed ≥ 10 packages during the three years. Among patients with diabetes mellitus on angiotensin converting enzyme inhibitors/angiotensin receptor antagonists and with presumed reduction in kidney function, 69.3% were prescribed non-steroidal anti-inflammatory drugs and 11.5% were prescribed ≥ 10 packages during the three years. DISCUSSION: The level of prescribing of non-steroidal anti-inflammatory drugs to patients with diabetes mellitus is high. The concern of reducing non-steroidal anti-inflammatory drugs prescription to patients already on angiotensin converting enzyme inhibitors/angiotensin receptor antagonists and/or decreased renal function does not seem to exist. CONCLUSION: In Portugal, the level of prescribing of non-steroidal anti-inflammatory drugs to patients with diabetes mellitus should be reduced, particularly in the subgroups identified with higher prescription and with higher risk of progression to stage 5 chronic kidney disease.

Avaliar a influência dos fatores biológicos, socioeconómicos e comportamentais no peso dos recém‐nascidos (RN), considerando RN de mães imigrantes (MI) e mães portuguesas (MP). Wilcox e Russel e modelos de regressão linear múltipla. Observaram‐se pesos mais baixos em RN do sexo feminino, idades gestacionais inferiores, mães adolescentes, não casadas ou em união de facto, escolaridade ≤ 12 anos, trabalhadoras manuais, residentes em «barracas», consumidoras de tabaco (MP), consumidoras de álcool (MI), paridade = 1, partos por cesariana (MI) ou eutócicos (MP) e não diabéticas. A distribuição residual de prematuridade revela maior vulnerabilidade nos RN de MI. Assess the influence of biological, socioeconomic and behavioural factors on the weight of newborn (NB) infants born from immigrant and Portuguese mothers (IM and PM respectively). Wilcox and Russell and multiple linear regression models. Lower birthweights in NBs that were female and of lower gestational age, and whose mothers were adolescent, unmarried or in de facto marriages, had ≤ 12 years schooling, manual workers, lived in shanties, consumed tobacco (PM), consumed alcohol (IM), parity = 1, had Caesarian (IM) or normal (PM) deliveries and were not diabetic. Residual distribution of prematurity shows higher vulnerability in babies born from IM.

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Abstract Background We used electronic health registries to estimate the mRNA vaccine effectiveness (VE) against COVID-19 hospitalizations and deaths in older adults. Methods We established a cohort of individuals aged 65 and more years, resident in Portugal mainland through data linkage of eight national health registries. For each outcome, VE was computed as one minus the confounder-adjusted hazard ratio, estimated by time-dependent Cox regression. Results VE against COVID-19 hospitalization ≥14 days after the second dose was 94% (95%CI 88 to 97) for age-group 65-79 years old (yo) and 82% (95%CI 72 to 89) for ≥80 yo. VE against COVID-19 related deaths ≥ 14 days after second dose was 96% (95%CI 92 to 98) for age-group 65-79 yo and 81% (95%CI 74 to 87), for ≥80 yo individuals. No evidence of VE waning was observed after 98 days of second dose uptake. Conclusions mRNA vaccine effectiveness was high for the prevention of hospitalizations and deaths in age-group 65-79 yo and ≥80 yo with a complete vaccination scheme, even after 98 days of second dose uptake.

BACKGROUND: In Autumn 2022, there were recommendations for a COVID-19 booster vaccination with adapted bivalent vaccines to eligible population. Evaluating vaccine effectiveness (VE), in a short period after the vaccination, is key to guide public health decisions on the vaccine performance, allowing implementation of mitigation strategies promptly. However, to assess long-term protection post-vaccination and evaluate the need for additional boosters, it is crucial to conduct studies that span the maximum duration of the vaccination program. This study aims to estimate the VE of bivalent mRNA vaccines against COVID-19-related hospitalisation and death in the Portuguese population aged 65 years or older, from September 2022 to May 2023. METHODS: We used a cohort approach to analyse six electronic health registries using deterministic linkage, with a follow-up period of eight months. Severe outcomes included COVID-19-related hospitalisations and death, classified using discharge ICD-10 codes as proxies. The exposure of interest was the bivalent mRNA vaccine. VE was estimated for 14-97, 98-181 and 182-240 days after bivalent vaccination. Confounder-adjusted hazard ratio (aHR) was obtained by fitting a time-dependent Cox regression model with time-dependent vaccination status, adjusted for sociodemographic, history of influenza and pneumococcus vaccination, previous SARS-CoV-2 tests and infection, and comorbidities. VE was estimated by one minus the aHR between vaccinated with bivalent vaccine person-years versus those without bivalent vaccine person-years. RESULTS: The cohort included 2,151,531 individuals aged 65 or older (27.8% with 80 or more years). In the ≥ 80 years old, VE was 41.3% (95%CI: 34.5-47.5%) and 50.3% (95%CI: 44.6-55.3%) against COVID-19-related hospitalisation and death, respectively. In the 65-79 years old, VE was 58.5% (95%CI: 51.9-64.2%) against COVID-19-related hospitalisation, and 65.1% (95%CI: 59.0-70.4%) against COVID-19-related death. VE waned for both age groups and outcomes. Among adults aged 65 years or older, we observed long-term moderate VE estimates against severe COVID-19-related outcomes. CONCLUSIONS: These results support the need for yearly boosters of COVID-19 vaccination to maximise the protection of the senior population against COVID-19 severe disease. Additional (spring boosters) during a vaccination campaign should be evaluated considering the epidemiological context and results from long-term VE studies.