Long-term trend of future Cancer onset: A model-based prediction of Cancer incidence and onset age by region and gender

OBJECTIVES

This study provided estimates of cancer incidence rate and onset age by Socio-demographic Index (SDI) regions and gender from 2020 to 2040, aiming to clarify the long-term patterns of future cancer onset.

METHOD

Based on the incidence data from the Global Burden of Diseases (GBD) 2019 study, we constructed the Bayesian age-period-cohort model to calculate the age-standardized incidence rates (ASIR) of cancers from 2020 to 2040. Using the average annual percentage change (AAPC) to quantify the trends of ASIR and the onset age. In addition, the incidences in 2019 were fixed to distinguish the age onset changes caused by demographic and incidence from 2020 to 2040.

RESULTS

Globally, two-thirds of cancers have escalating trends of incidence rate, and the proportion of cancer weighted average onset age above 60 years old will grow from 62% to 76% between 2020 and 2040. In five SDI regions, the proportion of weighted average onset age above 60 years old will rise above 10% in the next 20 years and increase sequentially with the rise of the SDI level. Preclude sex-specific cancers, the onset age is younger in men than in women in 2040. Rule out the influence of changing demographics, half of cancer's morbidity has a youth-oriented tendency globally, which is concentrated in hormone-related and digestive tract cancer.

CONCLUSION

From 2020 to 2040, the incidence and onset age changes demonstrate marked geographic and gender variations in the cancer spectrum. Cancer incidence and onset age are predicted to continuously increase worldwide in the future.

Cardiovascular disease burden attributable to non-optimal temperature: analysis of the 1990-2019 global burden of disease

AIMS

Extreme temperatures are increasingly experienced as a result of climate change. Both high and low temperatures, impacted by climate change, have been linked with cardiovascular disease (CVD). Global estimates on non-optimal temperature-related CVD are not known. The authors investigated global trends of temperature-related CVD burden over the last three decades.

METHODS AND RESULTS

The authors utilized the 1990-2019 global burden of disease methodology to investigate non-optimal temperature, low temperature- and high temperature-related CVD deaths, and disability-adjusted life years (DALYs) globally. Non-optimal temperatures were defined as above (high temperature) or below (low temperature) the location-specific theoretical minimum-risk exposure level or the temperature associated with the lowest mortality rates. Analyses were later stratified by sociodemographic index (SDI) and world regions. In 2019, non-optimal temperature contributed to 1 194 196 (95% uncertainty interval [UI]: 963 816-1 425 090) CVD deaths and 21 799 370 (95% UI: 17 395 761-25 947 499) DALYs. Low temperature contributed to 1 104 200 (95% UI: 897 783-1 326 965) CVD deaths and 19 768 986 (95% UI: 16 039 594-23 925 945) DALYs. High temperature contributed to 93 095 (95% UI: 10 827-158 386) CVD deaths and 2 098 989 (95% UI: 146 158-3 625 564) DALYs. Between 1990 and 2019, CVD deaths related to non-optimal temperature increased by 45% (95% UI: 32-63%), low temperature by 36% (95% UI: 25-48%), and high temperature by 600% (95% UI: -1879-2027%). Non-optimal temperature- and high temperature-related CVD deaths increased more in countries with low income than countries with high income.

CONCLUSION

Non-optimal temperatures are significantly associated with global CVD deaths and DALYs, underscoring the significant impact of temperature on public health.

Global, regional, and national burden of ischaemic heart disease and its trends, 1990-2019

OBJECTIVES

Ischemic heart disease (IHD) has high morbidity, disability, and mortality rates and is a major contributor to the global disease burden. This study aimed to obtain a more detailed description of the burden of IHD through secondary analysis of data from the Global Burden of Disease (GBD) 2019.

STUDY DESIGN

This is an epidemiological study.

METHODS

Data for this study were obtained from the GBD 2019 database. Annual average percentage change (AAPC) was calculated to assess trends in IHD prevalence, morbidity, mortality, and disability-adjusted life years (DALYs). Regional and national burden of IHD was assessed by stratifying by sex, age, and socio-demographic index (SDI).

RESULTS

From 1990 to 2019, the global prevalence of IHD, morbidity cases, deaths, and DALYs increased, but the age-standardized rates of IHD burden decreased. Morbidity, mortality, and DALY rates for IHD in both sexes increased with age. The prevalence, incidence, mortality, and DALY rates were higher in men than women in all age groups. In particular, the male-to-female ratios for mortality and DALY rates peaked among 35-39 year olds, while the male-to-female ratios for prevalence and morbidity peaked among 55-59 year olds. Age-standardized prevalence, incidence, and DALY rates were higher in low- and middle-income regions than in other SDI regions.

CONCLUSION

Although age-standardized prevalence, morbidity, mortality, and age-standardized DALY rates due to IHD decreased globally from 1990 to 2019, age-standardized prevalence and morbidity of IHD increased in Low SDI, Low-middle SDI, and Middle SDI regions.

Prevalence, incidence, deaths, and disability-adjusted life-years of drug use disorders for 204 countries and territories during the past 30 years

Drug use disorders are increasingly recognized as the main cause of public health issues worldwide. The current analysis aims to provide the most comprehensive, updated estimates of the burden from drug use disorders at global, regional, and national levels during the past three decades. Prevalence, incidence, deaths, and disability-adjusted life-years (DALYs) were estimated from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 by age and sex for drug use disorder as well as its four main categories (opioid use disorders, cocaine use disorders, amphetamine use disorders, and cannabis use disorders) in 204 countries and territories between 1990 and 2019. DisMod-MR 2.1, and Bayesian meta-regression were used to analyze prevalence and incidence, while the Cause of Death Ensemble model (CODEm) was used to estimate death of diseases. Globally, the burden of drug use disorders, as measured by the average annual percentage change (AAPC) of deaths and DALYs, continues to increase. The patterns by regions of DALYs due to drug use disorders varied significantly, and it is mainly in developed countries and concentrated among young people and males. Programs for drug use disorders management should be improved, particularly in opioid use disorders. Governments will face increasing demand for treatment and support services, and effective prevention as well as control strategies are required to reduce the burden from these causes.

Trends in urban air pollution over the last two decades: A global perspective

Ground-level ozone (O₃), fine particles (PM_2.5), and nitrogen dioxide (NO₂) are the most harmful urban air pollutants regarding human health effects. Here, we aimed at assessing trends in concurrent exposure of global urban population to O₃, PM_2.5, and NO₂ between 2000 and 2019. PM_2.5, NO₂, and O₃ mean concentrations and summertime mean of the daily maximum 8-h values (O₃ MDA8) were analyzed (Mann-Kendall test) using data from a global reanalysis, covering 13,160 urban areas, and a ground-based monitoring network (Tropospheric Ozone Assessment Report), collating surface O₃ observations at nearly 10,000 stations worldwide. At global scale, PM_2.5 exposures declined slightly from 2000 to 2019 (on average, - 0.2 % year^-1), with 65 % of cities showing rising levels. Improvements were observed in the Eastern US, Europe, Southeast China, and Japan, while the Middle East, sub-Saharan Africa, and South Asia experienced increases. The annual NO₂ mean concentrations increased globally at 71 % of cities (on average, +0.4 % year^-1), with improvements in North America and Europe, and increases in exposures in sub-Saharan Africa, Middle East, and South Asia regions, in line with socioeconomic development. Global exposure of urban population to O₃ increased (on average, +0.8 % year^-1 at 89 % of stations), due to lower O₃ titration by NO. The summertime O₃ MDA8 rose at 74 % of cities worldwide (on average, +0.6 % year^-1), while a decline was observed in North America, Northern Europe, and Southeast China, due to the reduction in precursor emissions. The highest O₃ MDA8 increases (>3 % year^-1) occurred in Equatorial Africa, South Korea, and India. To reach air quality standards and mitigate outdoor air pollution effects, actions are urgently needed at all governance levels. More air quality monitors should be installed in cities, particularly in Africa, for improving risk and exposure assessments, concurrently with implementation of effective emission control policies that will consider regional socioeconomic imbalances.

Severe acute respiratory syndrome coronavirus 2 infection altered the factors associated with headache: evidence from a multicenter community-based case–control study

INTRODUCTION

Headache is one of the significant global public health concerns. Furthermore, it is a standard feature of patients with acute and postacute COVID-19.

OBJECTIVES

This study aimed to estimate and compare the prevalence of headaches among postacute COVID and non-COVID individuals and identify and contrast the risk factors between both groups.

METHODS

This was a multicenter case-control study. Individuals who had recovered from acute SARS-CoV-2 infection were considered "case", and those who never tested positive for COVID-19 were considered "control." Headaches were measured using the musculoskeletal subscale of the subjective health complaints scale. Multiple logistic regression analysis was used to identify the predictors of headaches.

RESULTS

A total of 878 individuals (439 cases) aged 38.30 ± 12.77 years (mean ± standard deviation) participated in this study. The prevalence of headaches was 26.2% among COVID-19 survivors; however, only 10.7% of unaffected participants reported headaches at the same time. Regression analyses suggested that the recovery duration from acute COVID-19 ≤ 90 days (adjusted odds ratio [AOR] = 2.03, CI = 1.13-3.65) was the only predictor of headache among postacute COVID-19 survivors. However, the female gender (AOR = 3.09, 95% CI = 1.51-6.32), members of a joint family (AOR = 1.99, 95% CI = 1.02-3.90), and city dwellers (AOR = 2.43, 95% CI = 0.94-6.25) were the predictor of headache among non-COVID participants.

CONCLUSION

This study found a higher prevalence of headaches among COVID-19 survivors. In addition, predictors of headache among cases and controls were unmatched, indicating heterogenous impact of COVID-19 on human health. The health care providers should be informed of the study's results when discussing better practices to mitigate the burden of headaches.

Global Burden of Rheumatic Heart Disease and its Association with Socioeconomic Development Status, 1990-2019

AIMS

Rheumatic heart disease (RHD) remains an important health issue, yet global attention to RHD is diminishing. The aim of this study was to investigate the global burden of RHD and its relationship with socioeconomic development status.

METHODS AND RESULTS

Data were obtained from Global Burden of Disease (GBD) 2019 database. Incidence, prevalence, disability-adjusted life years (DALYs), and deaths numbers and rates for RHD were extracted and stratified by sex, level of socio-demographic index (SDI), country, and territory. In addition, the burden of RHD was compared across age groups. From 1990-2019, the age-standardized incidence and prevalence rates of RHD increased by 14.4% (11.2%-17.0%) and 13.8% (11.0%-16.0%), respectively. Incidence and prevalence rates showed an increasing trend in low SDI and low-middle SDI locations, while high-middle SDI and high SDI locations showed a decreasing trend. The age-standardized DALYs and deaths rates of RHD decreased by 53.1% (46.4-60.0) and 56.9% (49.8%-64.7%), and this downward trend more prominent in high-middle SDI and middle SDI locations. In addition, the age of incidence and prevalence rate were concentrated between 5-24 years and 15-49 years, predominantly in poor regions, and RHD appeared to be more common in women than in men.

CONCLUSION

The burden of RHD is negatively correlated with socioeconomic development status. In particular, the burden of RHD among children, adolescents, and women of childbearing age in poorer regions requires more attention. Policymakers should use the 2019 GBD data to guide cost-effective interventions and resource allocation for RHD.

Persisting burden and challenges of rheumatic heart disease

Rheumatic heart disease (RHD) is the result of episodes of acute rheumatic fever with valvular (and other cardiac) damage caused by an abnormal immune response to group A streptococcal infections, usually during childhood and adolescence. As a result of improved living conditions and the introduction of penicillin, RHD was almost eradicated in the developed world by the 1980s. However, being a disease of poverty, its burden remains disproportionately high in the developing world, despite being a fundamentally preventable disease. Rheumatic heart disease generates relatively little attention from the medical and science communities, in contrast to other common infectious problems (such as malaria, HIV, tuberculosis), despite the major cardiovascular morbidity/mortality burden imposed by RHD. This relative neglect and paucity of funding have probably contributed to limited fundamental medical advances in this field for over 50 years. Given the importance of prevention before the onset of major valvular damage, the main challenges for RHD prevention are improving social circumstances, early diagnosis, and effective delivery of antibiotic prophylaxis. Early identification through ultrasound of silent, subclinical rheumatic valve lesions could provide an opportunity for early intervention. Simple echocardiographic diagnostic criteria and appropriately trained personnel can be valuable aids in large-scale public health efforts. In addition, a better understanding of the immunogenic determinants of the disease may provide potential routes to vaccine development and other novel therapies.

Mapping the burden of diabetes in five small countries in Europe and setting the agenda for health policy and strategic action

BACKGROUND

Diabetes is a global epidemic affecting every country. Small countries, however, face distinctive challenges related to their health system governance and their ability to implement effective health systems' reforms. The aim of this research was to perform a comparative assessment of existing diabetes management practices at the population level and explore governmental-related policy for Cyprus, Iceland, Luxembourg, Malta and Montenegro. This is the first time that such an evidence-based review study has been performed in the field of diabetes. The overall purpose was to set the agenda for health policy and inform strategic actions for small countries that can benefit from dealing with the diabetes epidemic at a country level.

METHODS

We collected data and synthesized the evidence on dealing with diabetes for each of the five small European countries according to the (1) epidemiology of diabetes and other related metabolic abnormalities, (2) burden of diabetes status and (3) diabetes registers and national plans. We collected data by contacting Ministry representatives and other bodies in each state, and by searching through publicly available information from the respective Ministry of Health website on strategies and policies.

RESULTS

Diabetes rates were highest in Cyprus and Malta. National diabetes registers are present in Cyprus and Montenegro, while national diabetes plans and diabetes-specific strategies have been established in Cyprus, Malta and Montenegro. These three countries also offer a free holistic healthcare service to their diabetes population.

CONCLUSIONS

Multistakeholder, national diabetes plans and public health strategies are important means to provide direction on diabetes management and health service provision at the population level. However, political support is not always present, as seen for Iceland. The absence of evidence-based strategies, lack of funding for conducting regular health examination surveys, omission of monitoring practices and capacity scarcity are among the greatest challenges faced by small countries to effectively measure health outcomes. Nevertheless, we identified means of how these can be overcome. For example, the creation of public interdisciplinary repositories enables easily accessible data that can be used for health policy and strategic planning. Health policy-makers, funders and practitioners can consider the use of regular health examination surveys and other tools to effectively manage diabetes at the population level.

Are Europeans moving towards dietary habits more suitable for reducing cardiovascular disease risk?

AIMS

Cardiovascular diseases are the main cause of death in Europe. Food choices represent the most important factors undermining health and well-being; they account for as much as half of all CVD deaths in Europe. The aim of this viewpoint is to evaluate food choices of the European population and their temporal trends in relation to possible effects on the cardiovascular disease risk.

DATA SYNTHESIS

The CVD death rate attributable to diet-related factors has fallen in Europe over the last 25 years; however, the pace of the reduction has slowed down in the last ten years. In parallel, in the last decade unfavorable changes in the dietary habits associated with CVD risk have occurred.

CONCLUSIONS

A mismatch exists between the available evidence on the health-promoting potential of the diet and the relatively modest and inconsistent improvements of dietary habits in the European population observed in recent years. Nutritional education alone will not be enough to improve the lifestyle of people in Europe. Policy options to be considered to reach this aim should necessarily include also initiatives for facilitating production, marketing, availability and affordability of healthy foods in each and every European country.

The global, regional, and national burden of kidney cancer and attributable risk factor analysis from 1990 to 2017

BACKGROUND

Kidney cancer's incidence and mortality vary in different regions and countries. To compare and interpret kidney cancer's burden and change trends in the globe and in different countries, we conducted this study to report the global kidney cancer burden and attributable risk factors.

METHODS

Data about kidney cancer's incidence, death, disability-adjusted life-year (DALY) were extracted from the Global Burden of Diseases 2017. Besides, social-demographic index (SDI) values were adopted to investigate the correlation between kidney cancer's burden and social development degrees.

RESULTS

In the globe, the incidence case of kidney cancer increased sharply from 207.31*103 in 1990 to 393.04*103 in 2017. High SDI countries had the highest kidney cancer's burden with a decreased trend in incidence rate. On the contrary, the incidence rate was rapidly increased in low-middle SDI countries, although their burden of kidney cancer kept relatively low. At the same time, the deaths of kidney cancer increased from 68.14*103 to 138.53*103, and the kidney cancer-related DALYs increased from 1915.49*103 in 1990 to 3284.32*103 in 2017. Then, we searched the GBD database for kidney cancer-related risk factor. The high body-mass index and smoking were the main factors contributing to kidney cancer-related mortality.

CONCLUSIONS

Generally, from 1990 to 2017, the incidence rate in developed countries had gone down from the historic peak values while the incidence rate was still on the rise in developing counties. Given the aging trend in the globe, it is necessary to appeal to the public to decrease the exposure of kidney cancer-associated risk factors.

Burden of musculoskeletal disorders in Iran during 1990-2017: estimates from the Global Burden of Disease Study 2017

Musculoskeletal diseases (MSDs) are the leading cause of disability and facing them demands updated reports on their burden for efficient policymaking. We showed Iran had the highest female-to-male ratio and highest increase in the burden of musculoskeletal diseases, in the past three decades, worldwide. We further confirmed the role of population aging as the main cause.

PURPOSE

MSDs comprise most of the top causes of years lived with disability (YLDs) worldwide and are rapidly increasing in lower- and middle-income countries. Here, we present disability and mortality due to MSDs in Iran at the national level from 1990 to 2017.

METHODS

We used Global Burden of Disease (GBD) 2017 Study data and standard methodology and presented the burden of MSDs in rates of years of life lost (YLLs), YLDs, and disability-adjusted life years (DALYs) during 1990-2017, for population aged ≥ 5 years old. We further explored attributable risk factors and decomposed the changing trend in DALYs to assess underlying causes.

RESULTS

In Iran, MSDs were responsible for 1.82 million (95%uncertainty interval [UI] 1.3-2.4) DALYs, in 2017. During the past 28 years, with 1.75% annualized percentage change (APC), Iran had the highest percentage increase in the all-ages MSD DALYs rate worldwide, while the age-standardized DALYs APC was negligible. Low back pain was the greatest contributor to DALYs and caused 4.5% of total DALYs. The female population is experiencing considerably higher burden of MSDs, with 115% and 48% higher all-ages YLLs and YLDs rates per 100,000, respectively (YLLs 28.7; YLDs 2629.1), than males (YLLs 13.2; YLDs 1766.1). However, due to wide UIs, difference was not significant. Only 17.6% of MSD YLDs are attributable to assessed risk factors.

CONCLUSION

Despite that MSDs are rising as an important cause of disability in Iran, these conditions are not sufficiently addressed in health policies. There is urgent need for cross-sectoral engagement, especially addressing the MSDs in females.

Global Health - emergence, hegemonic trends and biomedical reductionism

Background

Global Health has increasingly gained international visibility and prominence. First and foremost, the spread of cross-border infectious disease arouses a great deal of media and public interest, just as it drives research priorities of faculty and academic programmes. At the same time, Global Health has become a major area of philanthropic action. Despite the importance it has acquired over the last two decades, the complex collective term “Global Health” still lacks a uniform use today.

Objectives

The objective of this paper is to present the existing definitions of Global Health, and analyse their meaning and implications. The paper emphasises that the term “Global Health” goes beyond the territorial meaning of “global”, connects local and global, and refers to an explicitly political concept. Global Health regards health as a rights-based, universal good; it takes into account social inequalities, power asymmetries, the uneven distribution of resources and governance challenges. Thus, it represents the necessary continuance of Public Health in the face of diverse and ubiquitous global challenges. A growing number of international players, however, focus on public-private partnerships and privatisation and tend to promote biomedical reductionism through predominantly technological solutions. Moreover, the predominant Global Health concept reflects the inherited hegemony of the Global North. It takes insufficient account of the global burden of disease, which is mainly characterised by non-communicable conditions, and the underlying social determinants of health.

Conclusions

Beyond resilience and epidemiological preparedness for preventing cross-border disease threats, Global Health must focus on the social, economic and political determinants of health. Biomedical and technocratic reductionism might be justified in times of acute health crises but entails the risk of selective access to health care. Consistent health-in-all policies are required for ensuring Health for All and sustainably reducing health inequalities within and among countries. Global Health must first and foremost pursue the enforcement of the universal right to health and contribute to overcoming global hegemony.

Global Updates on Cardiovascular Disease Mortality Trends and Attribution of Traditional Risk Factors

PURPOSE OF REVIEW

The last 2-3 decades have witnessed a decline in age-standardized cardiovascular mortality rates in high-income regions, whereas this has only slightly decreased or even increased in most of the low- and middle-income countries. A systematic comparison of global CVD mortality by regions attributable to various modifiable risk factors such as diabetes, obesity, hypertension, poor diet, and physical inactivity is not available.

RECENT FINDINGS

We present a summary of time trends and heterogeneity in the distribution of global CVD mortality and the attribution of risk factors between 1990 and 2017 using the Global Burden of Disease (GBD) 2017 study. Globally, an estimated ~ 17.8 million (233.1 per 100,000) people died of CVD in 2017. The rate of CVD death was decreased in high-income countries (1990: 271.8 (95% UI (uncertainty interval), 270.9-273.5); 2017: 128.5 (95% UI, 126.4-130.7) per 100,000)) whereas it remained the same in lower- and middle-income countries (1990: 368.2 (95% UI, 335.6-383.3); 2017: 316.9 (95% UI, 307.0-325.5) per 100,000). Among the various traditional risk factors, high systolic blood pressure, unhealthy diet, high fasting plasma glucose, and high low-density lipoprotein levels were attributed to most of the CVD death and disability-adjusted life year lost. We also observed gender variations in tobacco and increased alcohol consumption. In addition to the traditional risk factors, poor air quality is associated with increased CVD burden in developing countries. Surveillance, country-specific guidelines, evidence-based policies, reinforcement of multisectoral health systems, and innovative solutions are urgently needed in resource-challenged settings to curb CVD risk factors and overall burden.

Burden of gastrointestinal and liver diseases in India, 1990-2016

There is no comprehensive report on the burden of gastrointestinal (GI) and liver diseases in India. In this study, we estimated the age-standardized prevalence, mortality, and disability adjusted life years (DALY) rates of GI and liver diseases in India from 1990 to 2016 using data from the Global Burden of Disease (GBD) Study, which systematically reviews literature and reports for international disease burden trends. Despite a decrease in the overall burden from GI infectious disorders since 1990, they still accounted for the majority of DALYs in 2016. Among noncommunicable disorders (NCDs), there were increases in the prevalence and mortality rates for pancreatitis, liver cancer, paralytic ileus and intestinal obstruction, gallbladder and biliary tract cancer, vascular intestinal disorders, colorectal cancer, and inflammatory bowel disease. Prevalence and mortality rates decreased for peptic ulcer disease, hernias, appendicitis, and stomach and esophageal cancer. For gastritis and duodenitis, cirrhosis and other chronic liver diseases, and gallbladder and biliary tract diseases, there was an increase in prevalence but a decrease in mortality while the opposite was true for pancreatic cancer (decreased prevalence, increased mortality). Indian gastroenterologists and hepatologists must continue to attend to the large majority of patients with infectious diseases while also managing the increasing number of GI and liver diseases, noncommunicable nonmalignant and malignant.

A Burden Assessment of Occupational Exposures in Iran, 1990-2010: Findings from the Global Burden of Disease Study 2010

Background

The present study describes the burden of occupational diseases in Iran based on the results of the Global Burden of Disease study conducted in 2010 (GBD 2010). This study aimed to determine the burden of occupational diseases in Iran based on the results of GBD 2010. It is a cross-sectional study.

Methods

Disability-adjusted life years (DALYs) of occupational diseases were calculated based on the prevalence rates obtained through model estimation, as well as GBD 2010 disability weights and mortality rates obtained from different data registry systems of Iran. Causal association criteria application to select risk outcome pairs, estimation of exposure to each risk factor in the population, estimation of etiological effect size, selection of a counterfactual exposure distribution, risk assessment, and identification of burden attributable to each risk factor were the main conducted statistical steps.

Results

There was an increasing trend of DALYs (710.08/100,000 people in 1990 and 833.00/100,000 people in 2005) followed by a slight decrease (833.00/100,000 in 2005-784.55/100,000 people in 2010). A total of 50.4% and 36% of total DALYs per 100,000 people were due to the adverse effects of musculoskeletal disorders and work-related injuries, respectively.

Conclusions

Musculoskeletal disorders and work-related injuries are the most important adverse consequences of work-related risks that require urgent interventions to be controlled. Male workers (15-25 years and over 60) with the highest DALYs and mortality rates need more training programs, safety regulations, and higher level of protection support. In spite the decreasing trend of occupational disease related DALYs and death rates in Iran in recent years, a long-term effort is required to maintain the currently decreasing trend.

Automatic classification of registered clinical trials towards the Global Burden of Diseases taxonomy of diseases and injuries

Background

Clinical trial registries may allow for producing a global mapping of health research. However, health conditions are not described with standardized taxonomies in registries. Previous work analyzed clinical trial registries to improve the retrieval of relevant clinical trials for patients. However, no previous work has classified clinical trials across diseases using a standardized taxonomy allowing a comparison between global health research and global burden across diseases. We developed a knowledge-based classifier of health conditions studied in registered clinical trials towards categories of diseases and injuries from the Global Burden of Diseases (GBD) 2010 study.

The classifier relies on the UMLS® knowledge source (Unified Medical Language System®) and on heuristic algorithms for parsing data. It maps trial records to a 28-class grouping of the GBD categories by automatically extracting UMLS concepts from text fields and by projecting concepts between medical terminologies. The classifier allows deriving pathways between the clinical trial record and candidate GBD categories using natural language processing and links between knowledge sources, and selects the relevant GBD classification based on rules of prioritization across the pathways found. We compared automatic and manual classifications for an external test set of 2,763 trials. We automatically classified 109,603 interventional trials registered before February 2014 at WHO ICTRP.

Results

In the external test set, the classifier identified the exact GBD categories for 78 % of the trials. It had very good performance for most of the 28 categories, especially “Neoplasms” (sensitivity 97.4 %, specificity 97.5 %). The sensitivity was moderate for trials not relevant to any GBD category (53 %) and low for trials of injuries (16 %). For the 109,603 trials registered at WHO ICTRP, the classifier did not assign any GBD category to 20.5 % of trials while the most common GBD categories were “Neoplasms” (22.8 %) and “Diabetes” (8.9 %).

Conclusions

We developed and validated a knowledge-based classifier allowing for automatically identifying the diseases studied in registered trials by using the taxonomy from the GBD 2010 study. This tool is freely available to the research community and can be used for large-scale public health studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12859-016-1247-7) contains supplementary material, which is available to authorized users.