BACKGROUND: Initiatives aiming to assess the impact of rare diseases on population health might be hampered due to the complexity of disability-adjusted life years (DALYs) estimation. This study aimed to give insight into the epidemiological data sources and methodological approaches used in studies that estimated DALYs for chronic non-communicable rare diseases (CNCRD), and compare its results.
METHODS: A literature strategy was developed for peer-review search in Embase and Medline, and also performed on grey literature databases and population health and/or rare disease-focused websites. We included studies that determined the burden of CNCRD listed on the Orphanet\'s and/or the Genetic and Rare Diseases information center (GARD) websites. We excluded communicable and occupational diseases, rare cancers, and cost-effectiveness/benefit studies. Two researchers independently screened the identified records and extracted data from the final included studies. We used the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER) statement to assess the quality of reporting of the included studies. The data synthesis depicted the studies\' characteristics, their distribution by geographic coverage and the group of disease(s) they focused on, the methods and data input sources used and estimated DALY per case.
RESULTS: In total, 533 titles were screened, and 18 studies were included. These studies covered 19 different CNCRDs, of which most fell in the disease category \"Diseases of the nervous system\". Diverse methodological approaches and data input sources were observed among burden of CNCRD studies. A wide range of DALY per case was observed across the different studies and diseases included.
CONCLUSIONS: A low number of burden of CNCRD studies was observed and most estimates resulted from multi-country studies, underlining the importance of international cooperation to further CNCRD research. This study revealed a lack of epidemiological data and harmonization of methods which hampers comparisons across burden of CNCRD studies.

OBJECTIVE: Climate change is a major global issue with significant consequences, including effects on air quality and human well-being. This review investigated the projection of non-communicable diseases (NCDs) attributable to air pollution under different climate change scenarios.
METHODS: This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 flow checklist. A population-exposure-outcome framework was established. Population referred to the general global population of all ages, the exposure of interest was air pollution and its projection, and the outcome was the occurrence of NCDs attributable to air pollution and burden of disease (BoD) based on the health indices of mortality, morbidity, disability-adjusted life years, years of life lost and years lived with disability.
METHODS: The Web of Science, Ovid MEDLINE and EBSCOhost databases were searched for articles published from 2005 to 2023.
METHODS: The eligible articles were evaluated using the modified scale of a checklist for assessing the quality of ecological studies.
METHODS: Two reviewers searched, screened and selected the included studies independently using standardised methods. The risk of bias was assessed using the modified scale of a checklist for ecological studies. The results were summarised based on the projection of the BoD of NCDs attributable to air pollution.
RESULTS: This review included 11 studies from various countries. Most studies specifically investigated various air pollutants, specifically particulate matter <2.5 µm (PM2.5), nitrogen oxides and ozone. The studies used coupled-air quality and climate modelling approaches, and mainly projected health effects using the concentration-response function model. The NCDs attributable to air pollution included cardiovascular disease (CVD), respiratory disease, stroke, ischaemic heart disease, coronary heart disease and lower respiratory infections. Notably, the BoD of NCDs attributable to air pollution was projected to decrease in a scenario that promotes reduced air pollution, carbon emissions and land use and sustainable socioeconomics. Contrastingly, the BoD of NCDs was projected to increase in a scenario involving increasing population numbers, social deprivation and an ageing population.
CONCLUSIONS: The included studies widely reported increased premature mortality, CVD and respiratory disease attributable to PM2.5. Future NCD projection studies should consider emission and population changes in projecting the BoD of NCDs attributable to air pollution in the climate change era.
UNASSIGNED: CRD42023435288.

BACKGROUND: Syphilis is a sexually transmitted infection causing significant global morbidity and mortality. To inform policymaking and economic evaluation studies for syphilis, we summarised utility and disability weights for health states associated with syphilis.
METHODS: We conducted a systematic review, searching six databases for economic evaluations and primary valuation studies related to syphilis from January 2000 to February 2022. We extracted health state utility values or disability weights, including identification of how these were derived. The study was registered in the international prospective register of systematic reviews (PROSPERO, CRD42021230035).
RESULTS: Of 3401 studies screened, 22 economic evaluations, two primary studies providing condition-specific measures, and 13 burden of disease studies were included. Fifteen economic evaluations reported outcomes as disability-adjusted life years (DALYs) and seven reported quality-adjusted life years (QALYs). Fourteen of 15 economic evaluations that used DALYS based their values on the original Global Burden of Disease (GBD) study from 1990 (published in 1996). For the seven QALY-related economic evaluations, the methodology varied between studies, with some studies using assumptions and others creating utility weights or converting them from disability weights.
CONCLUSIONS: We found a limited evidence base for the valuation of health states for syphilis, a lack of transparency for the development of existing health state utility values, and inconsistencies in the application of these values to estimate DALYs and QALYs. Further research is required to expand the evidence base so that policymakers can access accurate and well-informed economic evaluations to allocate resources to address syphilis and implement syphilis programs that are cost-effective.

People with disabilities (PWDs) are often excluded from biomedical research, but comprehensive data regarding their participation in clinical trials are not available. The objective of this study was to assess the rates of exclusion of PWDs from recent medical scientific research.
The protocol of the study was designed according to PRISMA-ScR (PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) extension for Scoping Reviews) guidelines. All completed interventional clinical trials registered on ClinicalTrials.gov between 2010 and 2020 regarding the 10 leading causes of global disability-adjusted life-years according to the Global Burden of Disease Study were analysed. An exclusion criterion from the study was considered explicit if it could be associated with one of the following seven categories: disability, physical impairment, cognitive impairment, behavioural or psychiatric disorders, language and communication impairment, sensory impairment. Comorbidities not more clearly defined and researcher discretion regarding exclusion of study participants were considered to be \'implicit exclusion criteria\'. We assessed the appropriateness of explicit exclusion criteria in relation to the primary objectives of the trials and labelled them as \'absolute\', \'relative\' or \'questionable\'.
The total number of trials analysed was 2710; 170 were paediatric trials (6.3%), 2374 were adult trials (87.6%) and 166 were trials including subjects of all ages (6.1%). Explicit exclusion criteria were found in 958 trials (35.3%). The disability category most frequently excluded was behavioural or psychiatric disorders, present in 588 trials (61.4%). In only 3% and 1% of the trials, the exclusion criteria were considered either \'absolute\' or \'questionable\', while in 96% the exclusion criteria were judged as \'relative\'. Implicit exclusion criteria were present in 1205 trials (44.5%).
This study highlights the high rate of exclusion of PWDs from biomedical research and the widespread use of ill-defined exclusion criteria in clinical trials. It underscores the importance of more inclusive study designs so that PWDs can become active participants in research.

The emergence of COVID-19 has resulted in health, socio-economic, and political crises. The overall health impact of this disease can be measured by disability-adjusted life years (DALYs) which is the sum of the life years lost due to disability (YLDs) and the years life lost due to premature death (YLLs). The overarching objective of this systematic review was to identify the health burdens of COVID-19 and summarise the literature that can aid health regulators to make evidence-based decisions on COVID-19 mitigation strategies.
This systematic review was conducted using the PRISMA 2020 guidelines. DALYs-based primary studies were collected from databases, manual searches, and included studies\' references. The primary studies published in English language, conducted since the emergence of COVID-19, and using DALYs or its subsets (years life lost due to disability and/or years life lost due to premature death) as health impact metrics, were the inclusion criteria. The combined disability and mortality health impact of COVID-19 was measured in DALYs. The risk of bias due to literature selection, identification, and reporting processes was assessed using the Joanna Bridges Institute critical appraisal tool for cross-sectional studies, and the certainty of evidence was assessed using the GRADE Pro tool.
Of the 1459 identified studies, twelve of them were eligible for inclusion in the review. The years life lost due to COVID-19 related mortality was dominant over the years life lost due to COVID-19 related disability (disability times from the onset of COVID-19 to recovery, from diseases occurrence to mortality, and the long-term consequences of COVID-19) in all included studies. The long-term consequence disability time and the pre-death disability time were not assessed by most of the reviewed articles.
The impact of COVID-19 on both the length and quality of life has been substantial and has been causing considerable health crises worldwide. The health burden of COVID-19 was greater than other infectious diseases. Further studies focussing on issues examining increasing preparedness for future pandemics, public sensitization, and multi-sectorial integration are recommended.

This systematic literature review aimed to provide an overview of the characteristics and methods used in studies applying the disability-adjusted life years (DALY) concept for infectious diseases within European Union (EU)/European Economic Area (EEA)/European Free Trade Association (EFTA) countries and the United Kingdom. Electronic databases and grey literature were searched for articles reporting the assessment of DALY and its components. We considered studies in which researchers performed DALY calculations using primary epidemiological data input sources. We screened 3053 studies of which 2948 were excluded and 105 studies met our inclusion criteria. Of these studies, 22 were multi-country and 83 were single-country studies, of which 46 were from the Netherlands. Food- and water-borne diseases were the most frequently studied infectious diseases. Between 2015 and 2022, the number of burden of infectious disease studies was 1.6 times higher compared to that published between 2000 and 2014. Almost all studies (97%) estimated DALYs based on the incidence- and pathogen-based approach and without social weighting functions; however, there was less methodological consensus with regards to the disability weights and life tables that were applied. The number of burden of infectious disease studies undertaken across Europe has increased over time. Development and use of guidelines will promote performing burden of infectious disease studies and facilitate comparability of the results.

BACKGROUND: Recommendations and guidance from scientific bodies do not provide clear messages about potential health risks or benefits of coffee consumption. Numerous studies have demonstrated inverse (beneficial) effects of coffee consumption for many adverse outcomes such as cancer and cardiovascular disease; fewer studies demonstrate risks. However, the risk-benefit relationship has not yet been fully assessed using quantitative metrics preferred by policy makers (disability-adjusted life years [DALYs]).
OBJECTIVE: Conduct a quantitative analysis of the risk-benefit for coffee consumption and all-cause mortality using the Benefit-Risk Analysis for Foods (BRAFO) framework and the DALY as a quantitative metric.
METHODS: A systematic search and appraisal of meta-analyses investigating coffee consumption and all-cause mortality was conducted. Using the BRAFO framework, evidence was assessed in context of potential risks or benefits associated with the reference scenario - coffee consumption (assessed by varying the consumption level in three analyses) in adults aged 15+ versus the alternative scenario of no coffee consumption. DALYs were used to quantify risks and benefits based on risk ratios from meta-analyses with populations from the United States.
RESULTS: Meta-analyses consistently report an inverse (beneficial) relationship between coffee consumption and all-cause mortality; subsequently, even while varying consumption amounts and prevalence of coffee consumption, DALYs calculated consistently demonstrated findings in the direction of prevention of healthy years of life lost with variable magnitude. More than 3.5 million DALYs, or ∼3.35% of estimated years of healthy life lost could be prevented by consuming one cup of coffee per day, up to 4.7% of estimated years of healthy life lost could be prevented at current consumption rates ranging from 1 to 8 cups/day, and even more benefit could be seen (prevention of an estimated 6% of years of healthy life lost) if consumers all drank 3 cups of coffee per day.
CONCLUSIONS: Policy that directs consumers to avoid drinking coffee may be a detriment to the overall health of the population given the substantial potential benefits of coffee consumption on all-cause mortality for adults.

COVID-19 is a highly contagious infectious disease that emerged in 2019. This disease is causing devastating health, socio-economic, and economic crises. More specifically COVID-19 is affecting both the quality and length of human life. The overall health impact of this disease is measured by the disability-adjusted life years which is the sum of the life years lost due to disability (the effect on the health quality) and the years life lost due to premature death (effect on the length of life). The purpose of this review is to summarise DALYs-based health impact publications and produce compiled and informative literature that can aid the health regulators to make evidence-based decisions on mitigating COVID-19.
The review will be conducted using the PRISMA 2020 guidelines. The DALYs-based original observational and cross-sectional studies will be collected for assessing the health impact of COVID-19. Both the life quality and length impacts of COVID-19 will be reviewed. The life quality impact of COVID-19 will be measured using the life years lost due to disability (pre-recovery illness, pre-death illness, and post-acute consequences), and its impact on the length of life will be measured with years of life lost due to premature death (shortening of life expectancy). The combined health impact of COVID-19 on the quality and length of life will be measured in disability-adjusted life years.
The impacts of COVID-19 on the two health outcomes (quality and length of life) will indicate the level of COVID-19 health burden. The increase or decrease of COVID-19 health impact might be due to the sample size differences of different studies and the omission of years lost due to post-acute consequences in some studies. After having a summarized systematic review health decision-makers will apply an impact-based response to COVID-19.
Systematic review registration: This protocol is pre-registered in PROSPERO with the registration number CRD42022324931.

Calculating the disease burden due to injury is complex, as it requires many methodological choices. Until now, an overview of the methodological design choices that have been made in burden of disease (BoD) studies in injury populations is not available. The aim of this systematic literature review was to identify existing injury BoD studies undertaken across Europe and to comprehensively review the methodological design choices and assumption parameters that have been made to calculate years of life lost (YLL) and years lived with disability (YLD) in these studies.
We searched EMBASE, MEDLINE, Cochrane Central, Google Scholar, and Web of Science, and the grey literature supplemented by handsearching, for BoD studies. We included injury BoD studies that quantified the BoD expressed in YLL, YLD, and disability-adjusted life years (DALY) in countries within the European Region between early-1990 and mid-2021.
We retrieved 2,914 results of which 48 performed an injury-specific BoD assessment. Single-country independent and Global Burden of Disease (GBD)-linked injury BoD studies were performed in 11 European countries. Approximately 79% of injury BoD studies reported the BoD by external cause-of-injury. Most independent studies used the incidence-based approach to calculate YLDs. About half of the injury disease burden studies applied disability weights (DWs) developed by the GBD study. Almost all independent injury studies have determined YLL using national life tables.
Considerable methodological variation across independent injury BoD assessments was observed; differences were mainly apparent in the design choices and assumption parameters towards injury YLD calculations, implementation of DWs, and the choice of life table for YLL calculations. Development and use of guidelines for performing and reporting of injury BoD studies is crucial to enhance transparency and comparability of injury BoD estimates across Europe and beyond.

BACKGROUND: Taenia solium is the most significant global foodborne parasite and the leading cause of preventable human epilepsy in low and middle-income countries in the form of neurocysticercosis.
OBJECTIVE: This scoping review aimed to examine the methodology of peer-reviewed studies that estimate the burden of T. solium using disability-adjusted life years.
METHODS: Studies must have calculated disability-adjusted life years relating to T. solium.
METHODS: The review process was managed by a single reviewer using Rayyan. Published data relating to disease models, data sources, disability-adjusted life years, sensitivity, uncertainty, missing data, and key limitations were collected.
RESULTS: 15 studies were included for review, with seven global and eight national or sub-national estimates. Studies primarily employed attributional disease models that relied on measuring the occurrence of epilepsy before applying an attributable fraction to estimate the occurrence of neurocysticercosis-associated epilepsy. This method relies heavily on the extrapolation of observational studies across populations and time periods; however, it is currently required due to the difficulties in diagnosing neurocysticercosis. Studies discussed that a lack of data was a key limitation and their results likely underestimate the true burden of T. solium. Methods to calculate disability-adjusted life years varied across studies with differences in approaches to time discounting, age weighting, years of life lost, and years of life lived with disability. Such differences limit the ability to compare estimates between studies.
CONCLUSIONS: This review illustrates the complexities associated with T. solium burden of disease studies and highlights the potential need for a burden of disease reporting framework. The burden of T. solium is likely underestimated due to the challenges in diagnosing neurocysticercosis and a lack of available data. Advancement in diagnostics, further observational studies, and new approaches to parameterising disease models are required if estimates are to improve.