Association between the burden of behavioural risk factors and the number of primary studies included in Cochrane Systematic reviews

Article type
Authors
Madera Anaya MV1, Frassetto C2, Siebert M3, Megranahan K4, Roberts D5, Plugge E6
1University of Cartagena
2Catholic University of Sacred Heart
3Université de Rennes
4University of London
5University of Oxford
6Cochrane UK
Abstract
Background: Alcohol & drug use (A&D) and dietary risk are two increasingly important risk factors. It has been reported that there is a weak correlation between Cochrane Systematic Reviews (CSRs) of risk factors and their global risk burden. Likewise, only 19% of the corresponding authors in the CSRs are from low- and middle-income countries (LMICs) even though more than 83% of the global population live in these areas of the world.

Objectives: To examine whether there is an association between the burden of a risk factor in countries of specific income bands as defined by the World Bank, and the number of primary studies included in CSRs conducted in those countries.

Methods: We extracted data from primary studies included in CSRs assessing two risk factors (A&D and dietary risk) as outcomes. For each, we obtained data on its overall burden in disability-adjusted life years (DALYs) by World Bank Income Levels and calculated the correlation between DALYs and the number of primary studies and also their participants.

Results: We included 1601 studies from 96 CSRs. Only 18.3% of the global burden for A&D is in high income-countries (HICs) but they produced 90.5 % of primary studies and 99.5% participants. Only 14.2% of the dietary risk burden is in HICs but they produced 80.5% of primary studies and 98.1% participants.

Conclusions: This study demonstrates the significant imbalance of research heavily weighted towards HICs. More initiatives and collaborations are required to address this inequality and promote studies in LMICs for future global health research to address the disparity.

Patient or healthcare consumer involvement: This study did not involve healthcare consumers.