Further thoughts regarding evidence offered in support of the 'Barker hypothesis'.
The original objection to the paper by Kwong et al. was that the use of an inappropriate (between-pup) estimate of experimental error had exaggerated the importance of the maternal nutrition effect. From the group's most recent response, it has been possible to regenerate the raw data and carry out a further detailed analysis. It is apparent that despite now using a more sophisticated statistical tool, Kwong et al. have still, in effect, used the between-pup error, thus repeating the previous, probably exaggerated, finding. It is maintained that the nutrition effect should be studied using the between-rat variation, which then provides a result that is a good deal less emphatic. Further, it is felt that there is a very important point of principle involved in this dispute, relating to the rigorous analysis of hierarchical data, particularly in small studies.
Walters
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Babraham Institute and Churchill College Cambridge, UK. dew1@cus.cam.ac.uk
Edwards
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RG
D000704:Analysis of Variance; D000818:Animals; D001755:Blastocyst / Q000378:metabolism*; D019587:Dietary Supplements; D005260:Female; D008297:Male; D044342:Malnutrition / Q000378:metabolism*; D015233:Models, Statistical; D011247:Pregnancy; D011256:Pregnancy Outcome; D051381:Rats; D012044:Regression Analysis; D012107:Research Design