Der and colleagues show that the relationship between breastfeeding
and intelligence (IQ) in children is strongly confounded (and almost
eliminated) by the positive relationship between maternal IQ and breast
feeding.1 The difficulty of defining ‘breast feeding’ in this study
(acknowledged by the authors) is, however, a major weakness. Neither
frequency nor duration could be measured. The term “breast feeding” alone
is not sufficient to describe the numerous types of breastfeeding
behavior.2 Information about exposure, i.e. breast feeding frequency,
duration and intervals plus other information (such as type, timing and
amount of other feedings) are essential to evaluate the outcome of
interest (IQ).
I was also disappointed by the editing of this paper. In my view, the
conclusion of the abstract “Breast feeding has little or no effect on the
intelligence of children” seriously overstates the findings by omitting
key qualifications. While at the end of the article the editors comments
in “What this study adds” are slightly nuanced, they again mislead.
How readers approach our research reports matter. There is
variability in how journal articles are read.3;4 Practitioners may read
them to advise social policies or to shape interventions with families.
Many time-pressed readers only read the title and some of them will
continue reading the abstract only if the title attracts their interest.
Only, a minority read them from the first word of the title through the
last word of the discussion. In the breast feeding and intelligence
article, those who only read the abstract might be misled into considering
that any kind of breast feeding pattern has little or no effect on
intelligence in all children because they have missed key qualifications.
You may consider this as an error of the reader, but the consequences pull
out into family practice and policy with implications for people's lives.
On the other hand, I argue that this is an error on the part of authors.
There is a concern about how the authors of this article have not
presented the finding of short duration of breast feeding in non-low birth
weight children in the abstract. Furthermore, the misleading title could
have been changed to a more reflective one such as: Effect of short
duration breast feeding on intelligence in non-low birth weight children.
I believe every effort should be made to ensure that each section
accurately reflect the real concept behind the article.
Department of Community Health and Epidemiology, Queen’s university,
Kingston, Ontario, Canada, K7L 3N6, Canada.
Reference List
1. Der G, Batty GD, Deary IJ. Effect of breast feeding on
intelligence in children: prospective study, sibling pairs analysis, and
meta-analysis. BMJ 2006;333:945.
2. Labbok, M and Krasovec, K. Toward consistency in breastfeeding
definition. Studies in Family Planning, Vol.21, No.4, Jul.- Aug., 1990
21(4), 226-230. 1990.
3. Misiewicz G. How to Read a Paper: T Greenhalgh. London: BMJ
Publishing Group, 2001, {pound}16.95, illustrated, pp 222. ISBN 0 7279
1578 9. Gut 2002;50:442.
4. Walker AJ. Refracted Knowledge: Viewing Families Through the
Prism of Social Science. Journal of Marriage and Family 2000;62:595-608.
Competing interests:
None declared
Competing interests:
No competing interests
13 December 2006
Abbas Esmaeili
Medical Doctor, Copy Editor of JRMS
Isfahan University of Medical Sciences, Isfahan, Iran.
Rapid Response:
Missing key qualifications in title and abstract!
Der and colleagues show that the relationship between breastfeeding
and intelligence (IQ) in children is strongly confounded (and almost
eliminated) by the positive relationship between maternal IQ and breast
feeding.1 The difficulty of defining ‘breast feeding’ in this study
(acknowledged by the authors) is, however, a major weakness. Neither
frequency nor duration could be measured. The term “breast feeding” alone
is not sufficient to describe the numerous types of breastfeeding
behavior.2 Information about exposure, i.e. breast feeding frequency,
duration and intervals plus other information (such as type, timing and
amount of other feedings) are essential to evaluate the outcome of
interest (IQ).
I was also disappointed by the editing of this paper. In my view, the
conclusion of the abstract “Breast feeding has little or no effect on the
intelligence of children” seriously overstates the findings by omitting
key qualifications. While at the end of the article the editors comments
in “What this study adds” are slightly nuanced, they again mislead.
How readers approach our research reports matter. There is
variability in how journal articles are read.3;4 Practitioners may read
them to advise social policies or to shape interventions with families.
Many time-pressed readers only read the title and some of them will
continue reading the abstract only if the title attracts their interest.
Only, a minority read them from the first word of the title through the
last word of the discussion. In the breast feeding and intelligence
article, those who only read the abstract might be misled into considering
that any kind of breast feeding pattern has little or no effect on
intelligence in all children because they have missed key qualifications.
You may consider this as an error of the reader, but the consequences pull
out into family practice and policy with implications for people's lives.
On the other hand, I argue that this is an error on the part of authors.
There is a concern about how the authors of this article have not
presented the finding of short duration of breast feeding in non-low birth
weight children in the abstract. Furthermore, the misleading title could
have been changed to a more reflective one such as: Effect of short
duration breast feeding on intelligence in non-low birth weight children.
I believe every effort should be made to ensure that each section
accurately reflect the real concept behind the article.
Abbas Esmaeili, MD
6ae@qlink.queensu.ca
Department of Community Health and Epidemiology, Queen’s university,
Kingston, Ontario, Canada, K7L 3N6, Canada.
Reference List
1. Der G, Batty GD, Deary IJ. Effect of breast feeding on
intelligence in children: prospective study, sibling pairs analysis, and
meta-analysis. BMJ 2006;333:945.
2. Labbok, M and Krasovec, K. Toward consistency in breastfeeding
definition. Studies in Family Planning, Vol.21, No.4, Jul.- Aug., 1990
21(4), 226-230. 1990.
3. Misiewicz G. How to Read a Paper: T Greenhalgh. London: BMJ
Publishing Group, 2001, {pound}16.95, illustrated, pp 222. ISBN 0 7279
1578 9. Gut 2002;50:442.
4. Walker AJ. Refracted Knowledge: Viewing Families Through the
Prism of Social Science. Journal of Marriage and Family 2000;62:595-608.
Competing interests:
None declared
Competing interests: No competing interests