Re: Re: Does periodontal treatment cannot really prevent adverse pregnancy outcomes? A reappraisal and an alternative point of view
I have read Dr. Polyzos's answers to my previous comments with great
attention, but to my surprise he did not understand the purpose of my
rapid response. The explanations were clear and scientifically based and
are available to those who want to make a meticulous evaluation of
literature. As previous mentioned by my rapid response it was defined as
"an alternative point of view" and "a reappraisal".
It might be defined as an alternative point of view in such a way to
suggest that patients could be (and not should be) grouped according to
the methods used to determine periodontal disease (but it does not exclude
the possibility of supplementary analyses according to the risk of bias),
as well as that two other studies could be (and not should be) included in
the review. Just to be more clear, and according to the Cochrane Handbook
for Systematic Reviews of Interventions (1), "the classification of a
study as RCT or CCT is based solely on what the author has written, not on
the reader's interpretation, even when the sequence of randomization was
not adequately generated described". I suggest BMJ readers to have a look
at Box 6.3.a: Cochrane definitions and criteria for randomized controlled
trials (RCTs) and controlled clinical trials (CCTs); and Table 8.5.c:
Criteria for judging risk of bias in the 'Risk of bias' assessment tool.
With respect to the "reappraisal aspect", Dr. Polyzos has his point
of view, regarding the plausibility of mixing different diseases in the
same statistical model based on the inflammatory similarity of them (maybe
because of his obstetrician point of view ); however, it just simplifies
and does not take into consideration etiopathogenesis and specific aspects
related to the prognosis of such diseases. Furthermore, I did not suggest
him to exclude the data from Lopez et al. (2) from the review. Instead of
that, I suggest him just not to include it into meta-analyses. Once again,
I'm sorry that he could not understand my comments. Besides, the points
previously raised by my rapid response should be taken into consideration
as they were carefully based on an adequate source of literature (see
original response). Dr. Polyzos may not agree, but part of the data
extracted remains not adequate to answer the focused question raised by
his review. For instance, how could patients that did not receive
periodontal treatment be accounted as treated?
In addition, Dr. Polyzos energetically finished his comments stating
that "special attention should be also taken by those reading the
systematic reviews. Prior criticising an article one should very carefully
examine this article, rather than present critical but distorted opinions
due the misunderstanding of the article. Drawing conclusions which may,
the end, be unjustifiable and totally misleading, simply hampers medical
research". For sure, I agree with him, and at no time did I intend to "simply hamper medical research". On the other hand, it
becomes clear that he just doesn't want to consider eventual biases found
in his review. It is easy to say that my opinions were "distorted" or even
"misleading", but I still consider that special attention should be also
taken by those writing systematic reviews since an adequate appraisal of
the current literature and of the quality of systematic review is
mandated.
In summary, of the previous mentioned issues, two demands a special
attention of the readers: Periodontal diagnosis and data extraction. Thus,
I strongly suggest BMJ readers to take a careful look at the individual
RCTs (previously cited in my first response) to evaluate whether there are
inconsistencies concerning data extraction.
References
1) Higgins JPT, Green S. Cochrane handbook for systematic reviews of
interventions version 5.0.1 [updated September 2008] The Cochrane
Collaboration. Available at http://www.cochranehandbook.org (accessed 15
November 2008).
2) Lopez NJ, Da Silva I, Ipinza J, Gutierrez J. Periodontal therapy
reduces the rate of preterm low birth weight in women with
pregnancyassociated gingivitis. J Periodontol 2005;76(suppl 11):2144-2153.
Competing interests:
No competing interests
18 January 2011
Leandro Chambrone
DDS, MSc, PhD student in Periodontology
Division of Periodontics, School of Dentistry, University of Sao Paulo, Brazil
Rapid Response:
Re: Re: Does periodontal treatment cannot really prevent adverse pregnancy outcomes? A reappraisal and an alternative point of view
I have read Dr. Polyzos's answers to my previous comments with great
attention, but to my surprise he did not understand the purpose of my
rapid response. The explanations were clear and scientifically based and
are available to those who want to make a meticulous evaluation of
literature. As previous mentioned by my rapid response it was defined as
"an alternative point of view" and "a reappraisal".
It might be defined as an alternative point of view in such a way to
suggest that patients could be (and not should be) grouped according to
the methods used to determine periodontal disease (but it does not exclude
the possibility of supplementary analyses according to the risk of bias),
as well as that two other studies could be (and not should be) included in
the review. Just to be more clear, and according to the Cochrane Handbook
for Systematic Reviews of Interventions (1), "the classification of a
study as RCT or CCT is based solely on what the author has written, not on
the reader's interpretation, even when the sequence of randomization was
not adequately generated described". I suggest BMJ readers to have a look
at Box 6.3.a: Cochrane definitions and criteria for randomized controlled
trials (RCTs) and controlled clinical trials (CCTs); and Table 8.5.c:
Criteria for judging risk of bias in the 'Risk of bias' assessment tool.
With respect to the "reappraisal aspect", Dr. Polyzos has his point
of view, regarding the plausibility of mixing different diseases in the
same statistical model based on the inflammatory similarity of them (maybe
because of his obstetrician point of view ); however, it just simplifies
and does not take into consideration etiopathogenesis and specific aspects
related to the prognosis of such diseases. Furthermore, I did not suggest
him to exclude the data from Lopez et al. (2) from the review. Instead of
that, I suggest him just not to include it into meta-analyses. Once again,
I'm sorry that he could not understand my comments. Besides, the points
previously raised by my rapid response should be taken into consideration
as they were carefully based on an adequate source of literature (see
original response). Dr. Polyzos may not agree, but part of the data
extracted remains not adequate to answer the focused question raised by
his review. For instance, how could patients that did not receive
periodontal treatment be accounted as treated?
In addition, Dr. Polyzos energetically finished his comments stating
that "special attention should be also taken by those reading the
systematic reviews. Prior criticising an article one should very carefully
examine this article, rather than present critical but distorted opinions
due the misunderstanding of the article. Drawing conclusions which may,
the end, be unjustifiable and totally misleading, simply hampers medical
research". For sure, I agree with him, and at no time did I intend to "simply hamper medical research". On the other hand, it
becomes clear that he just doesn't want to consider eventual biases found
in his review. It is easy to say that my opinions were "distorted" or even
"misleading", but I still consider that special attention should be also
taken by those writing systematic reviews since an adequate appraisal of
the current literature and of the quality of systematic review is
mandated.
In summary, of the previous mentioned issues, two demands a special
attention of the readers: Periodontal diagnosis and data extraction. Thus,
I strongly suggest BMJ readers to take a careful look at the individual
RCTs (previously cited in my first response) to evaluate whether there are
inconsistencies concerning data extraction.
References
1) Higgins JPT, Green S. Cochrane handbook for systematic reviews of
interventions version 5.0.1 [updated September 2008] The Cochrane
Collaboration. Available at http://www.cochranehandbook.org (accessed 15
November 2008).
2) Lopez NJ, Da Silva I, Ipinza J, Gutierrez J. Periodontal therapy
reduces the rate of preterm low birth weight in women with
pregnancyassociated gingivitis. J Periodontol 2005;76(suppl 11):2144-2153.
Competing interests: No competing interests