technical paper
Factors Associated With Geographical Diversity of Reviewers Invited and Agreeing to Review for 21 Biomedical Journals
keywords:
diversity and inclusion
peer review
bias
Objective Geographical disparities have been observed in
the acquisition of research grants and in the submission and
publication of research articles. Peer reviewers are selected
primarily based on their expertise through publication
records. Response to peer invitation has been shown to be
related to relevance of topic to own work, reviewer
availability, journal attributes (impact factor and type of
reviewer blinding) and compensation. 1,2 However, diversity in
terms of geographical distribution in response to peer
invitations remains almost unexplored. 3
Design Retrospective cohort study of all research
manuscripts submitted to 21 BMJ Publishing Group
biomedical journals between January 1, 2018, and May 31,
2021, and subsequently sent for review. Data were collected
on geographical affiliation, income level of the country of
affiliation (according to World Bank Data 2020), journal
impact factor, and peer-review process (open vs
anonymized). The primary outcome was response (agreed vs
not agreed) to review invitation. A multivariable mixed-
effects logistic regression model with random factors on the
intercept at journal and manuscript levels was performed.
Results A total of 257,025 reviewers were invited to review
and 90,467 (35.2%) agreed. The distribution of geographical
affiliations of the invited reviewers were as follows: 10.0% in
Africa, 8.8% in Asia, 47.6% in Europe, 26.0% in North
America, 6.3% in Oceania, and 1.2% in South America.
Among invited reviewers, 217,682 (84.7%) were affiliated
with a high-income country. Figure 4 summarizes results
from multivariable analysis. Agreement was higher among
reviewers from Asia (2.13 95% CI, 2.05-2.21), Oceania (1.22
95% CI, 1.17-1.27), or South America (2.24 95% CI,
2.06-2.45) and lower among reviewers from Africa (0.43
95% CI, 0.42-0.45 compared with Europe (P < .001).
Agreement was significantly lower when the last author was
from Asia (0.85 95% CI, 0.83-0.87) or Oceania (0.91 95%
CI, 0.87-0.95) compared with Europe (P < .001). Reviewers
agreed significantly more often when the associated editor
had a North American institutional affiliation compared with
a European affiliation (1.07 95% CI, 1.02-1.12). Compared
with high-income countries, agreement was higher among
reviewers from lower middle–income countries (3.26 95%
CI, 3.06-3.48) and low-income countries (2.99 95% CI,
2.57-3.48) (P < .001). Agreement was also lower when the
last author was from an upper middle–income country (0.94
95% CI, 0.91-0.98) or low-income country (0.88 95% CI,
0.81-0.96) compared with a high-income country (P < .001).
Agreement was associated with impact factor (higher for
impact factors between 5 and 10, or >10, compared with <5:
1.73 95% CI, 1.29-2.32 and lower when peer-review process
was open compared with anonymized: 0.43 95% CI, 0.29-
0.64).
Conclusions The geographical affiliation of reviewers was
an independent factor associated with agreement to review.
To avoid bias and increase diversity, journal editors need to
invite more reviewers from upper middle–income or
lowincome countries.
References
1. Ellwanger JH, Chies JAB. We need to talk about
peerreview: experienced reviewers are not endangered
species, but they need motivation. J Clin Epidemiol.
2020;125:201-205. doi:10.1016/j.jclinepi.2020.02.001
2. Tite L, Schroter S. Why do peer reviewers decline to
review? a survey. J Epidemiol Community Health.
2007;61(1):9-12. doi:10.1136/jech.2006.049817
3. Masukume G, Grech V. The Lancet peer reviewers:
global pattern and distribution. Lancet.
2018;391(10140):2603-2604. doi:10.1016/S0140-
6736(18)31136-X
1 Department of Health and Community Medicine, University of
Geneva, Geneva, Switzerland, Khaoula.BenMessaoud@
unige.chkhaoula.benmessaoud@unige.ch; 2 Division of Clinical
Epidemiology, University Hospitals of Geneva, Geneva, Switzerland;
3 The BMJ, London, UK; 4 Article Transfer Service, BMJ Publishing
Group, London, UK
Conflict of Interest Disclosures All authors have completed the
ICMJE uniform disclosure form at https://www.icmje.org/disclosure-of-interest/
and declare support from the University
Hospitals of Geneva, Geneva Medical School, and the Swiss National
Science Foundation for the submitted work. Sara Schroter and Mark
Richards are full-time employees of BMJ Publishing Group but were
not involved in decision making on congress submissions. There were
no other relationships or activities that could appear to have
influenced the submitted work.
Funding/Support This study was supported by grant 192374 from
the Swiss National Science Foundation.
Role of the Funder/Sponsor The funder had no role in the design
and conduct of the study; collection, management, analysis, and
interpretation of the data; or preparation, review, or approval of the
abstract.