JACC VOL. 65, NO. 16, 2015
Letters
APRIL 28, 2015:1710–9
lowering the availability of serotonin in the brain
the entire spectrum of their papers or from the publi-
(3). Additionally, IFN- g is involved in cardiovascular
cation of a few highly-cited papers, such as clinical
pathology (4). An earlier study of CABG patients
practice guidelines. To address this question, we
demonstrated that greater IFN- g concentration in
quantified the variation in cardiovascular journals’
the 12 h after surgery predicted clinical cardiac
citation distributions and whether the variation was
outcomes at 12 months (5). Increased IFN-g there-
associated with the IF. Uneven citation distributions
fore provides a mechanistic link between depressive
can be studied with techniques that assess inequality.
symptoms and cardiac morbidity after CABG. These
One such measure is the Gini coefficient, which is uti-
observations are not only relevant to the mental
lized to characterize inequality in income distribu-
health of cardiac patients, but suggest that some of
tions. It has a range of 0 to 1, where a Gini coefficient of
the adverse cardiovascular effect of depression
0 represents perfect equality, meaning, in this case,
may be due to inflammatory processes. Targeting
that all papers have an equal number of citations (1).
inflammatory processes may have an impact on
We identified all journals from 2010 that primarily
depressive symptoms as well as potentially re-
published cardiovascular content (n ¼ 241) using
ducing cardiac morbidity.
SCImago (Granada, Spain), a third-party provider that categorizes journals into fields on the basis of journal
*Andrew Steptoe, DSc Lydia Poole, PhD Amy Ronaldson, MSc Tara Kidd, PhD Elizabeth Leigh, PhD Marjan Jahangiri
data obtained from the Scopus citation database. We used Scopus because it is a larger citation database than Thompson Reuters’ Web of Science, which provides the journal IF (2). We excluded journals with 70% (group C), and some plaques of the
Letters
APRIL 28, 2015:1710–9
lowering the availability of serotonin in the brain
the entire spectrum of their papers or from the publi-
(3). Additionally, IFN- g is involved in cardiovascular
cation of a few highly-cited papers, such as clinical
pathology (4). An earlier study of CABG patients
practice guidelines. To address this question, we
demonstrated that greater IFN- g concentration in
quantified the variation in cardiovascular journals’
the 12 h after surgery predicted clinical cardiac
citation distributions and whether the variation was
outcomes at 12 months (5). Increased IFN-g there-
associated with the IF. Uneven citation distributions
fore provides a mechanistic link between depressive
can be studied with techniques that assess inequality.
symptoms and cardiac morbidity after CABG. These
One such measure is the Gini coefficient, which is uti-
observations are not only relevant to the mental
lized to characterize inequality in income distribu-
health of cardiac patients, but suggest that some of
tions. It has a range of 0 to 1, where a Gini coefficient of
the adverse cardiovascular effect of depression
0 represents perfect equality, meaning, in this case,
may be due to inflammatory processes. Targeting
that all papers have an equal number of citations (1).
inflammatory processes may have an impact on
We identified all journals from 2010 that primarily
depressive symptoms as well as potentially re-
published cardiovascular content (n ¼ 241) using
ducing cardiac morbidity.
SCImago (Granada, Spain), a third-party provider that categorizes journals into fields on the basis of journal
*Andrew Steptoe, DSc Lydia Poole, PhD Amy Ronaldson, MSc Tara Kidd, PhD Elizabeth Leigh, PhD Marjan Jahangiri
data obtained from the Scopus citation database. We used Scopus because it is a larger citation database than Thompson Reuters’ Web of Science, which provides the journal IF (2). We excluded journals with 70% (group C), and some plaques of the
