Impact of the COVID-19 pandemic on delayed care of cardiovascular diseases in Europe: a systematic review.

BACKGROUND: Cardiovascular diseases remain the foremost global cause of death. The COVID-19 pandemic has strained health-care systems, leading to delays in essential medical services, including treatment for cardiovascular diseases. We aimed to examine the impact of the pandemic on delayed cardiovascular care in Europe. METHODS: In this systematic review, we searched PubMed, Embase, and Web of Science for peer-reviewed and published quantitative studies in English from Nov 1, 2019, to Sept 18, 2022, that addressed pandemic-induced delays in cardiovascular disease care for adult patients in Europe. Data appraisal, extraction, and quality assessment were done by two reviewers using the 14-item QualSyst tool checklist. We extracted summary patient-level data from the studies, including around 3·5 million patients. Evaluated outcomes included changes pre-March 2020 and during the COVID-19 pandemic in hospital admissions, mortality rates, medical help-seeking delays post-symptom onset, treatment initiation delays, and treatment procedure counts. The protocol is registered on PROSPERO (CRD42022354443). FINDINGS: Of the 132 included studies (20% from the UK), all were observational retrospective, with 87% focusing on the first wave of the pandemic. Results were categorised into five disease groups: ischaemic heart diseases, cerebrovascular diseases, cardiac arrests, heart failures, and others. Hospital admissions showed significant decreases around the ranges of 12-66% for ischaemic heart diseases, 9-40% for cerebrovascular diseases, 9-66% for heart failures, 27-88% for urgent and elective cardiac procedures, and an increase between 11-56% for cardiac arrests. Mortality rates were significantly higher during the pandemic, ranging between 1-25% (vs 16-22% before the pandemic) for ischaemic heart diseases and 8-70% (vs 8-26% before the pandemic) for cerebrovascular diseases. Only one study ranked low in quality. INTERPRETATION: The pandemic led to reduced acute CVD hospital admissions and increased mortality rates. Delays in seeking medical help were observed, while urgent and elective cardiac procedures decreased. Policymakers and health-care systems should work together on implementing adequate resource allocation strategies and clear guidelines on how to handle care during health crises, reducing diagnosis and treatment initiation delays, and promoting a healthy lifestyle. Future studies should evaluate the long-term impact of pandemics on delayed CVD care, and the health-economic impact of COVID-19. FUNDING: Belgian Science Policy Office.

Are air quality perception and PM2.5 exposure differently associated with cardiovascular and respiratory disease mortality in Brussels? Findings from a census-based study.

BACKGROUND: There is ample evidence that air pollution increases mortality risk, but most studies are based on modelled estimates of air pollution, while the subjective perception of air quality is scarcely assessed. We aimed to compare the effects of objective and subjective exposure to air pollution on cardiorespiratory mortality in Brussels, Belgium. METHODS: Data consisted of the 2001 Belgian census linked to registry-based mortality data for the follow-up period 2001-2014. We included individuals aged >30 years of age residing in Brussels at baseline (2001). Air pollution exposure was assessed with objective (modelled annual mean concentrations of PM2.5 in micrograms per cubic metre, µg/m3) and subjective indicators (poor self-reported air quality perception in the census). We used Cox Proportional Hazard models with age as the underlying time scale to evaluate associations with cardiovascular disease (CVD) and respiratory disease mortality, and separately, ischaemic heart disease (IHD), cerebrovascular disease, and COPD excluding asthma mortality. We specified single- and two-exposure models and evaluated effect modification by neighbourhood unemployment rate. RESULTS: 437,340 individuals were included at baseline. During follow-up (2001-2014), 22,821 (5%) individuals had died from CVDs and 8572 (2%) from respiratory diseases. In single-exposure models, PM2.5 was significantly associated with an increased risk in CVD and IHD mortality (e.g. for IHD, per 5 µg/m3 increase: Hazard Ratio, HR:1.22, 95%CI:1.08-1.37), and poor air quality perception with COPD excluding asthma mortality (HR:1.23, 95%CI:1.15-1.33). Associations remained significant in the two-exposure models, and additionally, perception was associated with respiratory disease mortality. Associations became gradually stronger with increasing neighbourhood unemployment rate [e.g. in the highest, Q3: PM2.5 and cerebrovascular disease mortality (HR:1.53, 95%CI:1.04-2.24)]. CONCLUSION: Our findings suggest that objective and subjective exposure to air pollution increased the risk of dying from cardiovascular and respiratory diseases respectively in Brussels. These results encourage policies reducing pollution load in Brussels whilst considering socio-economic inequalities.

Urban green spaces and suicide mortality in Belgium (2001-2011): A census-based longitudinal study.

BACKGROUND: Exposure to green spaces is associated with improved mental health and may reduce risk of suicide. Here, we investigate the association between long-term exposure to residential surrounding greenness and suicide mortality. METHODS: We used data from the 2001 Belgian census linked to mortality register data (2001-2011). We included all registered individuals aged 18 years or older at baseline (2001) residing in the five largest urban areas in Belgium (n = 3,549,514). Suicide mortality was defined using the tenth revision of the World Health Organisation International Classification of Diseases (ICD-10) codes X60-X84, Y10-Y34, and Y870. Surrounding greenness was measured using the Normalized Difference Vegetation Index (NDVI) within a 300 m and 1,000 m buffer around the residential address at baseline. To assess the association between residential surrounding greenness and suicide mortality, we applied Cox proportional hazards models with age as the underlying time scale. Models were adjusted for age, sex, living arrangement, migrant background, educational attainment, neighbourhood socio-economic position. We additionally explored potential mediation by residential outdoor nitrogen dioxide (NO2) concentrations. Finally, we assessed potential effect modification by various socio-demographic characteristics of the population (sex, age, educational attainment, migrant background, and neighbourhood socio-economic position). Associations are expressed as hazard ratios and their 95% confidence intervals (CI) for an interquartile range (IQR) increase in residential surrounding greenness. RESULTS: We observed a 7% (95%CI 0.89-0.97) and 6% (95%CI 0.90-0.98) risk reduction of suicide mortality for an IQR increase in residential surrounding greenness for buffers of 300 m and 1,000 m, respectively. Furthermore, this association was independent of exposure to NO2. After stratification, the inverse association was only apparent among women, and residents of Belgian origin, and that it was stronger among residents aged 36 or older, those with high level of education, and residents of most deprived neighbourhoods. CONCLUSION: Our results suggest that urban green spaces may protect against suicide mortality, but this beneficial effect may not be equally distributed across all strata of the population.

Employment trajectories and mental health-related disability in Belgium.

OBJECTIVES: An individual's quality of employment over time has been highlighted as a potential determinant of mental health. With mental ill-health greatly contributing to work incapacities and disabilities in Belgium, the present study aims to explore whether mental health, as indicated by registered mental health-related disability, is structured along the lines of employment quality, whereby employment quality is assessed over time as part of individuals' labour market trajectories. METHODS: Using administrative data from the Belgian Crossroads Bank for Social Security over 16 quarters between 2006 and 2009, transitions between waged jobs of varying quality (based on dimensions of income, working time, employment stability and multiple jobholding), self-employment, and unemployment are considered among individuals in the labour force aged 30-40 at baseline (n = 41,065 women and 45,667 men). With Multichannel Sequence Analysis and clustering, we constructed ideal types of employment trajectories. Fitting Cox regressions, we then evaluated individuals' hazard of experiencing a disability from a mental disorder between 2010 and 2016. RESULTS: Our analysis highlights various gender-specific trajectories. Among both genders, individuals exposed to near-constant unemployment over the initial 4 years showed the highest hazard of subsequent mental health-related disability compared to a group characterised by stable full-time employment, single jobholding, and above-median income. Trajectories involving a higher probability of subsidised and non-standard employment and (potential) spells of unemployment and lower relative income were also strong predictors of cause-specific disabilities. Health selection and confounding might, however, be contributing factors. CONCLUSIONS: Our study shows a gradient of mental disorders resulting in a disability along trajectory types. Our findings highlight the predictive power of labour market trajectories and their employment quality for subsequent mental disorder-related disability. Future research should examine the mechanisms, including selection effects in this association.

Exploring fertility preferences among women aged 15-24 in the Democratic Republic of Congo.

The DRC has one of the highest fertility rates globally, yet research on fertility preferences in the country remains limited. This study aims to identify the factors contributing to the persistence of high fertility preferences among young and adolescent women (15-24) in the DRC. Using data from the 2013-2014 DHS, the study examines fertility preferences by transition stage. Multinomial logistic regression analysis is used to identify the characteristics associated with mid- (4-5 children) and pre-transitional (6+ children) as opposed to post-transitional (0-3 children) preferences. Results reveal that 43% of the women prefer 6+ children. The relative risk of fertility preference varies significantly based on characteristics such as age, literacy, place and province of residence, religion, employment status, wealth, acceptance of domestic violence, and knowledge of modern family planning methods. The findings provide evidence for both the diffusion and socio-economic theory of fertility decline.

Long-term exposure to residential greenness and neurodegenerative disease mortality among older adults: a 13-year follow-up cohort study.

BACKGROUND: Living in greener areas is associated with slower cognitive decline and reduced dementia risk among older adults, but the evidence with neurodegenerative disease mortality is scarce. We studied the association between residential surrounding greenness and neurodegenerative disease mortality in older adults. METHODS: We used data from the 2001 Belgian census linked to mortality register data during 2001-2014. We included individuals aged 60 years or older and residing in the five largest Belgian urban areas at baseline (2001). Exposure to residential surrounding greenness was assessed using the 2006 Normalized Difference Vegetation Index (NDVI) within 500-m from residence. We considered all neurodegenerative diseases and four specific outcomes: Alzheimer's disease, vascular dementia, unspecified dementia, and Parkinson's disease. We fitted Cox proportional hazard models to obtain hazard ratios (HR) and 95% confidence intervals (CI) of the associations between one interquartile range (IQR) increment in surrounding greenness and neurodegenerative disease mortality outcomes, adjusted for census-based covariates. Furthermore, we evaluated the potential role of 2010 air pollution (PM2.5 and NO2) concentrations, and we explored effect modification by sociodemographic characteristics. RESULTS: From 1,134,502 individuals included at baseline, 6.1% died from neurodegenerative diseases during follow-up. After full adjustment, one IQR (0.22) increment of surrounding greenness was associated with a 4-5% reduction in premature mortality from all neurodegenerative diseases, Alzheimer's disease, vascular and unspecified dementia [e.g., for Alzheimer's disease mortality: HR 0.95 (95%CI: 0.93, 0.98)]. No association was found with Parkinson's disease mortality. Main associations remained for all neurodegenerative disease mortality when accounting for air pollution, but not for the majority of specific mortality outcomes. Associations were strongest in the lower educated and residents from most deprived neighbourhoods. CONCLUSIONS: Living near greener spaces may reduce the risk of neurodegenerative disease mortality among older adults, potentially independent from air pollution. Socioeconomically disadvantaged groups may experience the greatest beneficial effect.

Are we really all in this together? The social patterning of mortality during the first wave of the COVID-19 pandemic in Belgium.

BACKGROUND: Belgium was one of the countries that was struck hard by COVID-19. Initially, the belief was that we were 'all in it together'. Emerging evidence showed however that deprived socioeconomic groups suffered disproportionally. Yet, few studies are available for Belgium. The main question addressed in this paper is whether excess mortality during the first COVID-19 wave followed a social gradient and whether the classic mortality gradient was reproduced. METHODS: We used nationwide individually linked data from the Belgian National Register and the Census 2011. Age-standardized all-cause mortality rates were calculated during the first COVID-19 wave in weeks 11-20 in 2020 and compared with the rates during weeks 11-20 in 2015-2019 to calculate absolute and relative excess mortality by socioeconomic and -demographic characteristics. For both periods, relative inequalities in total mortality between socioeconomic and -demographic groups were calculated using Poisson regression. Analyses were stratified by age, gender and care home residence. RESULTS: Excess mortality during the first COVID-19 wave was high in collective households, with care homes hit extremely hard by the pandemic. The social patterning of excess mortality was rather inconsistent and deviated from the usual gradient, mainly through higher mortality excesses among higher socioeconomic groups classes in specific age-sex groups. Overall, the first COVID-19 wave did not change the social patterning of mortality, however. Differences in relative inequalities between both periods were generally small and insignificant, except by household living arrangement. CONCLUSION: The social patterning during the first COVID-19 wave was exceptional as excess mortality did not follow the classic lines of higher mortality in lower classes and patterns were not always consistent. Relative mortality inequalities did not change substantially during the first COVID-19 wave compared to the reference period.

Socioeconomic position, population density and site-specific cancer mortality: A multilevel analysis of Belgian adults, 2001-2011.

Our study explores the association between individual and neighborhood socioeconomic position (SEP) and all-cancer and site-specific cancer mortality. Data on all Belgian residents are retrieved from a population-based dataset constructed from the 2001 census linked to register data on emigration and mortality for 2001-2011. The study population contains all men and women aged 40 years or older during follow-up. Individual SEP is measured using education, employment status and housing conditions. Neighborhood SEP is measured by a deprivation index (in quintiles). Directly age-standardized mortality rates and multilevel Poisson models are used to estimate the association between individual SEP and neighborhood deprivation and mortality from all-cancer and cancer of the lung, colon and rectum, pancreas, prostate and female breast. The potential confounding role of population density is assessed using multilevel models as well. Our findings show an increase in mortality from all-cancer and site-specific cancer by decreasing level of individual SEP for both men and women. In addition, individuals living in highly deprived neighborhoods experience significantly higher mortality from all-cancer, lung cancer, pancreatic cancer and female colorectal cancer after controlling for individual SEP. Male colorectal and prostate cancer and female breast cancer are not associated with neighborhood deprivation. Population density acts as a confounder for female lung cancer only. Our study indicates that deprivation at both the individual and neighborhood level is associated with all-cancer mortality and mortality from several cancer sites. More research into the role of life-style related and clinical factors is necessary to gain more insight into causal pathway.

Evolution of socioeconomic inequalities in site-specific cancer mortality among Belgian women between 1991 and 2008 using a fundamental cause approach.

PURPOSE: According to the "fundamental cause theory", emerging knowledge on health-enhancing behaviours and technologies results in persisting and even widening health disparities, favouring the higher socioeconomic groups. This study aims to assess (trends in) socioeconomic inequalities in site-specific cancer mortality in Belgian women. METHODS: Data were derived from record linkage between the Belgian census and register data on mortality for 1991-1997 and 2001-2008 for all Belgian female inhabitants aged 50-79 years. Both absolute and relative inequalities by education and housing conditions were calculated. RESULTS: The results revealed persisting socioeconomic inequalities in total and site-specific cancer mortality. As expected, these inequalities were larger for the more preventable cancer sites. Generally, socioeconomic inequalities remained quite stable between the 1990s and the 2000s, although for some preventable cancer sites (e.g., uterus and oesophagus) a significant increase in inequality was observed. CONCLUSIONS: These persisting socioeconomic inequalities are likely due to differences in exposure to risk factors and unhealthy behaviours, and access and utilization of healthcare across the social strata. Since equality in health should be a priority for a fair public health policy, efforts to reduce inequalities in risk behaviours and access and use of health care should remain high on the agenda.

Evolution of educational inequalities in site-specific cancer mortality among Belgian men between the 1990s and 2000s using a "fundamental cause" perspective.

BACKGROUND: According to the "fundamental cause" theory, emerging knowledge on health-enhancing behaviours and technologies results in health disparities. This study aims to assess (trends in) educational inequalities in site-specific cancer mortality in Belgian men in the 1990s and the 2000s using this framework. METHODS: Data were derived from record linkage between the Belgian censuses of 1991 and 2001 and register data on mortality. The study population comprised all Belgian men aged 50-79 years during follow-up. Both absolute and relative inequality measures have been calculated. RESULTS: Despite an overall downward trend in cancer mortality, educational differences are observed for the majority of cancer sites in the 2000s. Generally, inequalities are largest for mortality from preventable cancers. Trends over time in inequalities are rather stable compared with the 1990s. CONCLUSIONS: Educational differences in site-specific cancer mortality persist in the 2000s in Belgium, mainly for cancers related to behavioural change and medical interventions. Policy efforts focussing on behavioural change and healthcare utilization remain crucial in order to tackle these increasing inequalities.

Trends in site- and sex-specific cancer mortality between 1979 and 2010 in Belgium compared with Europe using WHO data.

BACKGROUND: Cancer mortality constitutes a major health burden in Europe. Trends are different for men and women, and across Europe. This study aims to map out Belgian cancer mortality trends for the most common cancer types in both sexes between 1979 and 2010, and to link these with trends in cancer mortality and smoking prevalence across Europe. METHODS: Mortality and population data were obtained from the World Health Organization Mortality Database. Age-standardized mortality rates were calculated by direct standardization using the European Standard Population. RESULTS: Belgian mortality decreased for the most common cancer sites between 1979 and 2010, except for female lung cancer. Yet, Belgian male lung and female breast cancer rates remain high compared with the remainder of Western Europe. For some cancer sites, mortality trends are similar among the European Regions (e.g. stomach cancer), yet for others trends are divergent (e.g. colorectal cancer). CONCLUSIONS: Generally, cancer mortality shows a favorable trend in Belgium and Europe. Yet, female lung cancer mortality rates are increasing in Belgium. Furthermore, Belgium still has higher male lung and female breast cancer mortality rates compared with the European regional averages. Considering this and the current smoking prevalence, enduring tobacco control efforts should be made.

Socioeconomic disparities in lung cancer mortality in Belgian men and women (2001-2011): does it matter who you live with?

BACKGROUND: Ample studies have observed an adverse association between individual socioeconomic position (SEP) and lung cancer mortality. Moreover, the presence of a partner has shown to be a crucial determinant of health. Yet, few studies have assessed whether partner's SEP affects health in addition to individual SEP. This paper will study whether own SEP (education), partner's SEP (partner's education) and own and partner's SEP combined (housing conditions), are associated with lung cancer mortality in Belgium. METHODS: Data consist of the Belgian 2001 census linked to register data on cause-specific mortality for 2001-2011. The study population includes all married or cohabiting Belgian inhabitants aged 40-84 years. Age-standardized lung cancer mortality rates (direct standardization) and mortality rate ratios (Poisson regression) were computed for the different SEP groups. RESULTS: In men, we observed a clear inverse association between all SEP indicators (own and partner's education, and housing conditions) and lung cancer mortality. Men benefit from having a higher educated partner in terms of lower lung cancer mortality rates. These observations hold for both middle-aged and older men. For women, the picture is less uniform. In middle-aged and older women, housing conditions is inversely associated with lung cancer mortality. As for partner's education, for middle-aged women, the association is rather weak whereas for older women, there is no such association. Whereas the educational level of middle-aged women is inversely associated with lung cancer mortality, in older women this association disappears in the fully adjusted model. CONCLUSIONS: Both men and women benefit from being in a relationship with a high-educated partner. It seems that for men, the educational level of their partner is of great importance while for women the housing conditions is more substantial. Both research and policy interventions should allow for the family level as well.

Health status and mortality rates of adolescents and young adults in the Brussels-Capital Region: differences according to region of origin and migration history.

OBJECTIVE: To examine and quantify differences in both self-rated health (SRH) and mortality according to region of origin, migration history and educational level among adolescents and young adults living in the Brussels-Capital Region (BCR). DESIGN: The data consist of the census of 2001 for the BCR linked to death and emigration records for the period of 01/10/2001-01/01/2006. Belgian, Maghreb, Turkish and sub-Saharan African 15-34 year olds are included in the analyses. Odds ratios are calculated for SRH (0 = poor health, 1 = good health) using logistic regression. Age-standardised mortality rates are computed and mortality rate ratios are shown using Poisson regression. RESULTS: There are marked health differences according to region of origin. While Maghrebins and Turks (M/T) feel less healthy, sub-Saharan Africans (SSA) feel healthier than Belgians. Furthermore, there are important differences within nationality groups, with second-generation M/T having a worse health status than the first generation. While first-generation SSA feel a lot healthier than Belgians, there is no difference between second-generation SSA and Belgians. Education plays a marked role in health and mortality differences, especially in young adulthood (25-34 years). Migration history is even more important than region of origin concerning mortality differences. First-generation M/T show lower mortality risks compared to Belgians and second-generation M/T, while the latter show comparable mortality risks as Belgians after controlling for education. CONCLUSION: Important differences are observed according to both region of origin and migration history among adolescents and young adults in the BCR. These differences significantly reduce when accounting for education, suggesting that investing in education is a public-health strategy worth considering. Further research in this area may benefit from taking migration history into account.

Trapped in Place? Ethnic and Educational Heterogeneity in Residential Mobility and Integration of Young Adults in Brussels.

Spatial assimilation theory asserts that immigrants' socioeconomic progress leads to residential adaptation and integration. This association has proven robust in USA and European urban areas through much of the twentieth century, but drastic change of ethnic and class compositions yet persistent (neighbourhood) inequality in the urban landscape urge us to reconsider the dynamic interaction between stability and change. In this study, we investigate to what extent education shapes residential mobility differently for young adults with varying ethnic and social origins. Focussing on Brussels, we use multinomial logistic regressions on linked longitudinal population-based censuses from 1991 and 2001 and register data for the period 2001-2006. Analyses show that dispersal away from poor inner-city neighbourhoods appears least likely for the offspring of poor low-educated non-Western households, regardless of their own educational attainment. While our approach roughly confirms traditional arguments of socio-spatial integration, it also reveals how educational success generates opportunities to escape poor neighbourhoods for some but not for others. With this, it points at the subtle ways in which factors and mechanisms in traditional spatial assimilation theory affect residential behaviour of young adults over their life course, at the intersection of specific locales, ethnic groups, social classes and generations.

Socioeconomic Disparities in Neurodegenerative Disease Mortality: A Population-Based Study among Belgian Men and Women Aged 65 or Older.

This study investigates the association between socioeconomic position (SEP) - in terms of income and education - and mortality from neurodegenerative diseases, that is, dementia, parkinsonism, and motor neuron diseases (MNDs). We calculated age-standardized mortality rates and mortality rate ratios using log linear Poisson regression for different SEP groups, stratified by gender, age-group, and care home residency, utilizing the 2011 Belgian census linked to register data on cause-specific mortality for 2011 to 2016. Mortality was significantly higher in the lowest educational- and income groups. The largest disparities were found in dementia mortality. Income had a strong negative effect on parkinsonism mortality, education a positive effect. We found no significant association between SEP and MND. Our study provides evidence supporting the presence of socioeconomic disparities in mortality due to neurodegeneration. We found a strong negative association between SEP and NDD mortality, which varies between NDD, gender and care home residency.

Correction: Evaluating the health and health economic impact of the COVID-19 pandemic on delayed cancer care in Belgium: A Markov model study protocol.

[This corrects the article DOI: 10.1371/journal.pone.0288777.].

The impact of the COVID-19 pandemic on delayed care of cardiovascular diseases in Europe: a systematic review.

AIMS: Cardiovascular diseases (CVD) are the leading cause of death worldwide. The coronavirus disease 2019 (COVID-19) pandemic has disrupted healthcare systems, causing delays in essential medical services, and potentially impacting CVD treatment. This study aims to estimate the impact of the pandemic on delayed CVD care in Europe by providing a systematic overview of the available evidence. METHODS AND RESULTS: PubMed, Embase, and Web of Science were searched until mid-September 2022 for studies focused on the impact of delayed CVD care due to the pandemic in Europe among adult patients. Outcomes were changes in hospital admissions, mortality rates, delays in seeking medical help after symptom onset, delays in treatment initiation, and change in the number of treatment procedures. We included 132 studies, of which all were observational retrospective. Results were presented in five disease groups: ischaemic heart diseases (IHD), cerebrovascular accidents (CVA), cardiac arrests (CA), heart failures (HF), and others, including broader CVD groups. There were significant decreases in hospital admissions for IHD, CVA, HF and urgent and elective cardiac procedures, and significant increases for CA. Mortality rates were higher for IHD and CVA. CONCLUSION: The pandemic led to reduced acute CVD hospital admissions and increased mortality rates. Delays in seeking medical help were observed, while urgent and elective cardiac procedures decreased. Adequate resource allocation, clear guidelines on how to handle care during health crises, reduced delays, and healthy lifestyle promotion should be implemented. The long-term impact of pandemics on delayed CVD care, and the health-economic impact of COVID-19 should be further evaluated.

Correction: Evaluating the health and health economic impact of the COVID-19 pandemic on delayed cancer care in Belgium: A Markov model study protocol.

[This corrects the article DOI: 10.1371/journal.pone.0288777.].

Evaluating the health and health economic impact of the COVID-19 pandemic on delayed cancer care in Belgium: A Markov model study protocol.

INTRODUCTION: Cancer causes a substantial burden to our society, both from a health and an economic perspective. To improve cancer patient outcomes and lower society expenses, early diagnosis and timely treatment are essential. The recent COVID-19 crisis has disrupted the care trajectory of cancer patients, which may affect their prognosis in a potentially negative way. The purpose of this paper is to present a flexible decision-analytic Markov model methodology allowing the evaluation of the impact of delayed cancer care caused by the COVID-19 pandemic in Belgium which can be used by researchers to respond to diverse research questions in a variety of disruptive events, contexts and settings. METHODS: A decision-analytic Markov model was developed for 4 selected cancer types (i.e. breast, colorectal, lung, and head and neck), comparing the estimated costs and quality-adjusted life year losses between the pre-COVID-19 situation and the COVID-19 pandemic in Belgium. Input parameters were derived from published studies (transition probabilities, utilities and indirect costs) and administrative databases (epidemiological data and direct medical costs). One-way and probabilistic sensitivity analyses are proposed to consider uncertainty in the input parameters and to assess the robustness of the model's results. Scenario analyses are suggested to evaluate methodological and structural assumptions. DISCUSSION: The results that such decision-analytic Markov model can provide are of interest to decision makers because they help them to effectively allocate resources to improve the health outcomes of cancer patients and to reduce the costs of care for both patients and healthcare systems. Our study provides insights into methodological aspects of conducting a health economic evaluation of cancer care and COVID-19 including insights on cancer type selection, the elaboration of a Markov model, data inputs and analysis.

Social inequalities and long-term health impact of COVID-19 in Belgium: protocol of the HELICON population data linkage.

INTRODUCTION: Data linkage systems have proven to be a powerful tool in support of combating and managing the COVID-19 pandemic. However, the interoperability and the reuse of different data sources may pose a number of technical, administrative and data security challenges. METHODS AND ANALYSIS: This protocol aims to provide a case study for linking highly sensitive individual-level information. We describe the data linkages between health surveillance records and administrative data sources necessary to investigate social health inequalities and the long-term health impact of COVID-19 in Belgium. Data at the national institute for public health, Statistics Belgium and InterMutualistic Agency are used to develop a representative case-cohort study of 1.2 million randomly selected Belgians and 4.5 million Belgians with a confirmed COVID-19 diagnosis (PCR or antigen test), of which 108 211 are COVID-19 hospitalised patients (PCR or antigen test). Yearly updates are scheduled over a period of 4 years. The data set covers inpandemic and postpandemic health information between July 2020 and January 2026, as well as sociodemographic characteristics, socioeconomic indicators, healthcare use and related costs. Two main research questions will be addressed. First, can we identify socioeconomic and sociodemographic risk factors in COVID-19 testing, infection, hospitalisations and mortality? Second, what is the medium-term and long-term health impact of COVID-19 infections and hospitalisations? More specific objectives are (2a) To compare healthcare expenditure during and after a COVID-19 infection or hospitalisation; (2b) To investigate long-term health complications or premature mortality after a COVID-19 infection or hospitalisation; and (2c) To validate the administrative COVID-19 reimbursement nomenclature. The analysis plan includes the calculation of absolute and relative risks using survival analysis methods. ETHICS AND DISSEMINATION: This study involves human participants and was approved by Ghent University hospital ethics committee: reference B.U.N. 1432020000371 and the Belgian Information Security Committee: reference Beraadslaging nr. 22/014 van 11 January 2022, available via https://www.ehealth.fgov.be/ehealthplatform/file/view/AX54CWc4Fbc33iE1rY5a?filename=22-014-n034-HELICON-project.pdf. Dissemination activities include peer-reviewed publications, a webinar series and a project website.The pseudonymised data are derived from administrative and health sources. Acquiring informed consent would require extra information on the subjects. The research team is prohibited from gaining additional knowledge on the study subjects by the Belgian Information Security Committee's interpretation of the Belgian privacy framework.