Disparities in Cardiovascular Research Output and Disease Outcomes among High-, Middle- and Low-Income Countries - An Analysis of Global Cardiovascular Publications over the Last Decade (2008-2017)

Abstract

Background: Cardiovascular disease (CVD) is the leading cause of death and disability worldwide. Health research is crucial to managing disease burden. Previous work has highlighted marked discrepancies in research output and disease burden between high-income countries (HICs) and low- and lower-middle-income countries (LI-LMICs) and there is little data to understand whether this gap has bridged in recent years. We conducted a global, country level bibliometric analysis of CVD publications with respect to trends in disease burden and county development indicators.

Methods: A search filter with a precision and recall of 0.92 and 0.91 respectively was developed to extract cardiovascular publications from the Web of Science (WOS) for the years 2008-2017. Data for disease burden and country development indicators were extracted from the Global Burden of Disease and the World Bank database respectively.

Results: Our search revealed 847,708 CVD publications for the period 2008-17, with a 43.4% increase over the decade. HICs contributed 81.1% of the global CVD research output and accounted for 8.1% and 8.5% of global CVD DALY losses deaths respectively. LI-LMICs contributed 2.8% of the total output and accounted for 59.5% and 57.1% global CVD DALY losses and death rates.

Conclusions: A glaring disparity in research output and disease burden persists. While LI-LMICs contribute to the majority of DALYs and mortality from CVD globally, their contribution to research output remains the lowest. These data call on national health budgets and international funding support to allocate funds to strengthen research capacity and translational research to impact CVD burden in LI-LMICs.

Keywords: Bibliometrics; Cardiovascular disease burden; Low middle income countries; global cardiovascular health; low income countries.

Figure 1

Absolute counts of cardiovascular publications (2008–2017).

Figure 2

Population, cardiovascular DALY, deaths and publications in World Bank income groups as percentages of global figures.

Figure 3

(i) Ranking of top 10 countries based on contribution to the 10-year cardiovascular research output of each income group. The width of the bar represents magnitude of contribution. Numbers for each country are its CV publications integer counts as a percentage of total CV publication integer counts of its income group. (ii) Percentage increase in integer counts of cardiovascular publications in top 10 countries based on contribution to total research output of each income group from 2008 to 2017.

Figure 4

Hover over heat-map showing publication rates per 100,000 population based on integer counts (attached).

Figure 5

Logarithmic cardiovascular publication integer counts against Human Development index for the year 2013. Each bubble represents a country (n = 181). Size of the bubble represents the country population and color represents World Bank income group.

Figure 6

Trends in integer counts of cardiovascular publications and age-standardized DALY rates of cardiovascular disease in World Bank income groups (2008–2017). Shadowed portion represents forecasted values.

Figure 7

Logarithmic cardiovascular publication integer counts against age-standardized cardiovascular disease DALY rates per 100,000 population of for the year 2013. Each bubble represents a country (n = 181). Size of the bubble represents the country population and color represents World Bank income group.

Figure 8

Trends in integer counts of cardiovascular publications and age-standardized death rates of cardiovascular disease in World Bank income groups (2008–2017). Shadowed portion represents forecasted values.

Figure 9

Logarithmic cardiovascular publication integer counts against age-standardized cardiovascular disease death rates per 100,000 population of for the year 2013. Each bubble represents a country (n = 181). Size of the bubble represents the country population and color represents World Bank income group.