Concentration of Research on Physical Activity and Health by Country: A Global Analysis of Authors and Institutions Using the Gini Coefficient.

Background: Physical activity research is pivotal in shaping policies and interventions that promote health. However, disparities in research contributions across authors and institutions can impact the equity and representation of evidence-based practices.

Objective: This study aimed to assess the dispersion of authors and institutions publishing research on physical activity and health within countries.

Methods: A global bibliometric analysis was conducted, including articles on physical activity and health published between 1950 and 2019. Countries with 10 or more publications were analyzed. Data on authors' names and institutions were extracted, and the Gini coefficient, a measure of inequality, was calculated using the "Descogini" command in Stata. Gini coefficients were generated for authors in 94 countries and for institutions in 98 countries.

Results: The Gini coefficient for authors ranged from 0.03 in Cuba, Bangladesh, and Lebanon (low concentration) to 0.59 in Belgium and 0.65 in Portugal (high concentration). For institutions, the lowest coefficient was 0.08 in Guatemala, and the highest was 0.84 in Belgium and Portugal. Regions such as the Americas, Europe, and the Western Pacific exhibited higher average Gini coefficients for authors and institutions. Similarly, high-income and upper middle-income countries showed greater research concentration than low-income and lower middle-income nations.

Conclusion: To promote a more equitable and impactful global research landscape, it is crucial to invest strategically in developing and multiplying high-quality research groups across regions. Supporting emerging centers of excellence will foster innovation, capacity building, and more inclusive scientific production. Future research should further explore these factors to guide effective policies and investments.