Letter by Kerr and Lees Regarding Article, “Country Comparisons of Human Stroke Research Since 2001: A Bibliometric Study”
To the Editor:
We read with interest Asplund et al's1 bibliometric study of stroke research. They undertook an international comparison of the quantity and quality of stroke research from 2001 to 2011. They found that by far the leading producer of stroke research articles was the United States followed by Japan, the United Kingdom, and Germany.1 The methodology they describe, using the bibliometric software Bibexcel,2 is versatile and can be readily brought to bear in other situations such as comparisons between regions and cities within the same country.
In their analysis, the United Kingdom is treated as 1 unit; however, the United Kingdom is not a homogeneous entity. Long-standing differences in economic prosperity and health exist between England and the Celtic fringe of Scotland, Wales, and Northern Ireland. Even within England, similar differences exist between the prosperous southeast and the rest of the country. Moreover, over the past decade, the devolution of powers to regional governments has seen health care and higher educational policies diverge between England and the Celtic nations, particularly Scotland.
We modified Asplund et al's search terms1 to identify all stroke research articles from January 2001 until October 2011 with at least 1 author based in the United Kingdom. On these citations we used Bibexcel to calculate the sums of publication fractions and H-indices for the constituent nations of the United Kingdom. For England, Scotland, Wales, and Northern Ireland, the sums of publication fractions were 3159.4, 564.5, 77.6, and 10.6, respectively. Their H-indices were 180, 104, 29, and 15, respectively. We adjusted our sums of publication fractions for population and economic activity (as measured by gross value added) based on data from the UK Office of National Statistics.3,4 Adjusting for population, the sums of publication fractions per 100 000 population for England, Scotland, Wales, and Northern Ireland were: 6.0, 10.8, 2.6, and 0.6, respectively. The sums of publication fraction per £100 000 of gross value added were 298.3, 550.5, 174.3, and 36.0, respectively.
We also used Poisson regression to determine the average annual relative change in publication fractions for each nation.1 For England and Scotland these were 5.79% (95% CI, 4.56–7.01) and 4.94% (95% CI, 2.03–7.85), respectively. For Wales and Northern Ireland, this annual change did not reach statistical significance.
As can be seen, there is a marked disparity of stroke research between the constituent nations of the United Kingdom. Research output and quality is high in Scotland, particularly considering its small population of approximately 5.2 million2 in comparison to England's population of approximately 52.2 million2 and its markedly smaller economy with a gross value added of £102 552 in comparison to England's £1 059 120. Relative to its population and economy, Scotland produces a high volume of high-impact stroke research, similar to that of other small northern European nations as identified in Asplund et al's original article.
The methodology described can be easily used to compare stroke research output between regions and cities within a country. Such research will help identify centers of excellence within a country and, in conjunction with detailed local data on factors such as stroke incidence, acute stroke services provision, and stroke research funding, may help elucidate the factors determining the distribution of stroke research.
Daniel M. Kerr, BSc
Kennedy R. Lees, MD, FRCP
Institute of Cardiovascular and Medical Sciences
University of Glasgow
Dr Lees is Associate Director of the National Institute for Health Research Stroke Research Network (NIHR SRN) and chaired the independent data monitoring committee for the European Cooperative Acute Stroke Study (ECASS) III trial, chairs the Virtual International Stroke Trials Archive (VISTA) collaboration, and served of the Steering Committee for the Safe Implementation of Treatments in Stroke (SITS) collaboration. He has received fees and expenses from Boehringer Ingelheim for committee work and lectures.
Stroke welcomes Letters to the Editor and will publish them, if suitable, as space permits. Letters must reference a Stroke published-ahead-of-print article or an article printed within the past 3 weeks. The maximum length is 750 words including no more than 5 references and 3 authors. Please submit letters typed double-spaced. Letters may be shortened or edited. Include a completed copyright transfer agreement form (available online at http://stroke.ahajournals.org and http://submit-stroke.ahajournals.org).
- © 2012 American Heart Association, Inc.
- Asplund K,
- Eriksson M,
- Perrsson O
- Persson O
Office for National Statistics. Population Estimates for UK, England and Wales, Scotland and Northern Ireland, Mid-2010 Population Estimates. Available at: www.ons.gov.uk/ons/publications/re-reference-tables.html?edition=tcm%3A77-231847. Accessed October 23, 2011.
Office for National Statistics. Regional Economic Activity (GVA), Regional GVA. December 2010. Available at: http://www.ons.gov.uk/ons/rel/regional-accounts/regional-gross-value-added–income-approach-/december-2010/regional-gva.pdf. Accessed October 21, 2011.