Thanks to Jette Clausen (JC) and Eva Rydahl (ER) for their
considerations on our study on stillbirths.
JC and ER suggest our interpretation being "overly optimistic" due to
our observational design. But again, observational studies have identified
a long list of causes of diseases, be it lung cancer among smokers, venous
thrombosis among users of hormonal contraception, greenhouse gas emissions
as a cause of global...
Thanks to Jette Clausen (JC) and Eva Rydahl (ER) for their
considerations on our study on stillbirths.
JC and ER suggest our interpretation being "overly optimistic" due to
our observational design. But again, observational studies have identified
a long list of causes of diseases, be it lung cancer among smokers, venous
thrombosis among users of hormonal contraception, greenhouse gas emissions
as a cause of global warming, etc. Not only do we identify and quantify
causes by observations, we also act according to the knowledge they bring.
By combining different observational strategies we may actually achieve
evidence of causation, amounting almost to certainty.
So a well confounder controlled study may actually bring new
knowledge, which should - of course - be confirmed by other independent
studies, but which in the end may bring progress in our clinical practice.
So much in general on interpreting observational studies.
And no, we have examined a long list of fetal and neonatal outcomes.
Our first publication, however, focused on stillbirths. We have submitted
the next paper assessing the frequency of asphyxia, cerebral palsy,
neonatal deaths, Apgar score, referral to neonatal intensive care units,
shoulder dystocia, and peripheral nerve injuries with the more proactive
induction practice, and look forward to continue the discussion with these
new data.
The stochastic year-to-year variations in stillbirth rates don't
change the convincing and substantial declining trend in stillbirth rates
by time, a decline which was steeper after 2009 than before 2009.
And no, we did not restrict the study window to the period 2009 to
2012 but to the 13-year period 2000-2012, and we acknowledged that several
factors in addition to the more proactive induction contributed to the
fall in stillbirths. About preeclampsia and intrauterine growth
restriction, please see our reply to Carbillon, Hosseraye & Mekinian.
We have as JC and ER also noticed a still very low stillbirth rate in
2013, actually the next lowest ever measured. Isn't that reassuring?
Thanks to Lionel Carbillon, Claire de la Hosseraye & Arsene
Mekinian for their interest in and comments to our paper on stillbirth
reduction in Denmark with a more proactive induction practice.
No doubt, that the improved ultrasound monitoring of pregnancies at
term is expected to have decreased the stillbirth rates all over the
industrialised world. It is also true, that the stillbirth rates may be
higher...
Thanks to Lionel Carbillon, Claire de la Hosseraye & Arsene
Mekinian for their interest in and comments to our paper on stillbirth
reduction in Denmark with a more proactive induction practice.
No doubt, that the improved ultrasound monitoring of pregnancies at
term is expected to have decreased the stillbirth rates all over the
industrialised world. It is also true, that the stillbirth rates may be
higher in women with preeclampsia and intrauterine growth restriction.
The number of deaths after 37 weeks associated with IUGR was around 6
per year without any consistent trend during the study period. The
adjusted hazard ratio of stillbirth among women with IUGR was 1.85 (1.4-
2.5). And the mean gestational age at delivery among women with IUGR was
stable during the study period (39 weeks +/- 1 day). Thus, IUGR had a
relatively little share of the total number of fetal deaths from 37 weeks,
and did not play any confounding role on the influence of inductions.
The number of women with preeclampsia (or more correctly with a
diagnosis of preeclampsia) increased through the study period, but
stillbirths in women with preeclampsia were slightly decreasing from 6 to
4 deaths per year. The HR of stillbirths among women with preeclampsia was
not significantly elevated. The average gestational age at delivery among
women with preeclampsia was (surprisingly) stable through the study
period; 39 + 1-2. The confounding influence from preeclampsia on the
influence of induction was not significant.
Our point was and still is that the more intensive surveillance of
women with IUGR or preeclampsia did not differ from our neighbour
countries. While the stillbirth rates have been rather stable in these
countries, our stillbirth rates were substantially reduced. Therefore, we
don't think that these two conditions or the handling of them, can explain
the substantial reduction in stillbirths in Denmark, especially not the
decrease after 40 weeks, at which time the majority of women with these
two conditions have delivered.
Earlier induction in women having passed 40 weeks is certainly not the
only contributing factor for the decrease in stillbirths in Denmark. We
already had a low rate 10 years ago, but have experienced a further
substantial reduction with the new induction practice, a reduction not
seen in other countries. Thus, we still think that the more proactive
induction practice has the main responsibility for this recent decrease.
This is a fascinating study into infections during onset and progress
of RA.
I have recently been investigating potential roles for herpes
viruses, especially cytomegalovirus (CMV), in a series of infectious-like
outbreaks seen within the UK over many years. These outbreaks lead to
increased deaths and hospital admission for a range of medical conditions
which include allergy[1-9]. There are several areas of pot...
This is a fascinating study into infections during onset and progress
of RA.
I have recently been investigating potential roles for herpes
viruses, especially cytomegalovirus (CMV), in a series of infectious-like
outbreaks seen within the UK over many years. These outbreaks lead to
increased deaths and hospital admission for a range of medical conditions
which include allergy[1-9]. There are several areas of potential cross-
over with this study.
Firstly, a review of the role of CMV in autoimmune diseases has
suggested that this immune modulating virus may act to exacerbate symptoms
[10].
CMV has also been circumstantially implicated in a range of
respiratory symptoms which appear to be associated with the outbreaks seen
in the UK [11] and noted in this study.
Hence would it be possible for the authors to re-evaluate their data
to see if the infectious episodes cluster in time around 2002, 2007 and
2012 (not included in the study which is however presumably on-going) - or
at least roughly five years apart? My own studies indicate that the 2012
outbreak can be seen in over 9 European countries (unpublished) and Russia
is unlikely to be an exception.
High fever of uncertain origin (as reported in the study) is one
potential red flag for an active CMV infection.
The study may well be too small, but could the authors also look and
see if there is a disproportionate incidence of appendicitis, since the
outbreaks in the UK also appear to be in some way linked to surges in the
incidence of appendicitis [12].
References
1. Jones R (2013) Could cytomegalovirus be causing widespread
outbreaks of chronic poor health. In Hypotheses in Clinical Medicine, pp
37-79, Eds M. Shoja, et al. New York: Nova Science Publishers Inc.
Available from: http://www.hcaf.biz/2013/CMV_Read.pdf
2. Jones R (2013) Recurring outbreaks of a subtle condition leading
to hospitalization and death. Epidemiology: Open access 4(3): 137.
3. Jones R (2013) Do recurring outbreaks of a type of infectious
immune impairment trigger cyclic changes in the gender ratio at birth?
Biomedicine International 4(1): 26-39.
4. Jones R (2013) A recurring series of infectious-like events
leading to excess deaths, emergency department attendances and medical
admissions in Scotland. Biomedicine International 4(2): 72-86.
5. Jones R, Goldeck D (2014) Unexpected and unexplained increase in
death due to neurological disorders in 2012 in England and Wales: Is
cytomegalovirus implicated? Medical Hypotheses 83(1): 25-31.
6. Jones R (2014) Unexpected single-year-of-age changes in the
elderly mortality rate in 2012 in England and Wales. British Journal of
Medicine and Medical Research 4(16): 3196-3207.
7. Jones R (2014) Infectious-like Spread of an Agent Leading to
Increased Medical Admissions and Deaths in Wigan (England), during 2011
and 2012. British Journal of Medicine and Medical Research 4(28): 4723-
4741.
8. Jones R (2014) Trends in admission for allergy. British Journal of
Healthcare Management 20(7): 350-351.
9. Jones R (2014) Infectious-like spread of an agent leading to
increased medical hospital admission in the North East Essex area of the
East of England. Biomedicine International 5(1): in press
10. Jones R (2014) Roles for cytomegalovirus in infection,
inflammation and autoimmunity. In Infection and Autoimmunity, 2nd Edition,
Eds: N Rose, et al. Elsevier: Amsterdam. (in press)
11. Jones R (2014) A Study of an Unexplained and Large Increase in
Respiratory Deaths in England and Wales: Is the Pattern of Diagnoses
Consistent with the Potential Involvement of Cytomegalovirus? British
Journal of Medicine and Medical Research 4(33): 5179-5192.
12. Jones R (2014) An unexpected increase in adult appendicitis in
England (2000/01 to 2012/13): Could cytomegalovirus (CMV) be a risk
factor? British Journal of Medicine and Medical Research (in press)
A call for humility on the Reduction in stillbirths at term after new
birth induction paradigm
Hedegaard et al state in their recent article: Reduction in
stillbirths at term after new birth induction paradigm: results of a
national intervention, that they 'see no reason why a similar, more
proactive induction paradigm could not be implemented in other countries'
(1). Their observational study design limits dra...
A call for humility on the Reduction in stillbirths at term after new
birth induction paradigm
Hedegaard et al state in their recent article: Reduction in
stillbirths at term after new birth induction paradigm: results of a
national intervention, that they 'see no reason why a similar, more
proactive induction paradigm could not be implemented in other countries'
(1). Their observational study design limits drawing conclusions about
causality, and their overly optimistic interpretation of the data provide
good reason to proceed with caution.
Is stillbirth the best and only outcome measure?
All interventions carry risks for mother and unborn. Although the
authors mention risks associated with inductions they do not provide any
data on maternal risk and only limited data on risk to the foetus.
Hedegaard et al base their conclusion mainly on differences in
stillbirth rates and deaths the first week. The overwhelming importance to
parents is whether they can celebrate future birthdays with their healthy
child or not, not that they only reached full term with a live foetus. Neo
-, peri- or infant mortality rates provides essential information to
monitor delayed complications of induction these measures is however not
used in this article. According to the official published Danish
statistics on birth outcome there has not been any significant change from
2009-12 in the overall perinatal mortality (2,3).
What is the best way to make conclusions about causality from
observational data?
When reviewing observational data, the conclusions can radically
change based on broadening the time frame, or by excluding or including
"anomalous" data points.
We planned to add figure 1. here, however the BMJ comment system does
not allow us to upload pictures. You can access the relevant figures here:
http://figshare.com/articles/A_call_for_humility_on_the_Reduction_in_stillbirths_at_term_after_new_birth_induction_paradigm/1157865
Figure 1. contains crude data from the Medical Birth Register
(including all Danish birth from 1996-2013 from 37+0 weeks and onwards).
The red curve illustrates stillbirth rates. The authors highlight that:
'The fall [in stillbirth] was steepest from 2009-2010 to 2011-2012' and
they link the steep decrease to the change in the 2009 guidelines about
induction of labour. However, the rate of stillbirths actually increased
in 2010. The authors' selective reporting of annual data does not help
explain the trends and variations in incidences, and it paves the way for
a conclusion that is unfounded. One might even notice a slight increase in
stillbirth in 2013 which is after the study period (4).
Stillbirth is the one side of the equation on the other side is
inductions; let's now take a look at this (Figure 2).
Figure 2. Induction rates 1997-2023 in %. You can access it here:
http://figshare.com/articles/A_call_for_humility_on_the_Reduction_in_stillbirths_at_term_after_new_birth_induction_paradigm/1157865
Figure 2. shows a rather steep increase in number of inductions 1997-
2001, a stable period 2002-2007, and a steep increase 2008 -2013.
However, the stillbirth rate appears to decline continuously over time and
if we overlay the two figures, it does not mirror the change pattern in
induction rates. Hedegaard et al. utilize a narrow time frame between the
years 2009-12 to support an argument in favour of early induction.
However one peak or decrease in the dataset of an observational study
is not sufficient to draw strong conclusions. The Cochrane handbook
recommends that studies like Hedegaard et al. which utilize a single
intervention or studies which do not clearly define a period of time
course through which the intervention was carried out should adhere to an
additional level of scrutiny. In particular, The Cochrane Collaboration
recommends at least three data points prior to and three after the
intervention, in order to strengthen conclusions from these weaker study
designs. Reviewing Hedegaard et al with this in mind, it is unclear if the
authors are utilizing one or two interventions (the guidelines or
inductions). And because the intervention itself is unclear it is
difficult to determine the time course through which the intervention was
carried out.
Does the data support induction in gestational week 41 +3 to reduce
stillbirths?
We acknowledge, as we mentioned earlier, the decrease in stillbirth
throughout the study period. We are however not convinced that 'the
striking decreases in risk of late foetal deaths is likely primarily to be
due to the earlier and increased induction rates' (our emphasis). Numerous
additional factors are still not accounted for by the authors. Others
rightfully highlighted that the study did not control for a range of
relevant factors, such as birth defects, IUGR, and socio-economic status
to name only a few. Also, the presented data shows that the stillbirth
decreased in all gestational weeks after 37 weeks. This decrease in
stillbirth in week 37+0-6 weeks is curious, especially if we are supposed
to conclude that induction accounts for the decrease in stillbirth from 37
weeks. It has not been common practice in Denmark to induce in the 37+0-6
gestational week except in rare cases, and this decrease suggests that
factors other than induction of labour, such as improved surveillance,
could significantly contribute.
This study raises many methodological questions, we have pointed to a
few of them. We believe that the conclusions drawn from this study are too
far reaching.
Will the correct intervention please step forward?
Hedegaard et al suggests that other countries should implement a
proactive induction regime including early induction of labour for low
risk women. We suggest a more humble approach that acknowledges multiple
factors interacting in this significant decrease in stillbirths beyond the
37. gestational week over the last decades. Also we have significant
concerns about unleashing a technology intensive solution, such as
induction of labour, especially on women with normal and uncomplicated
deliveries. We see no reason why this more proactive induction paradigm
should be exported to other countries as the authors do not present data
that support such a strong conclusion.
1) Hedegaard M, Lidegaard O, Skovlund CW, M?rch LS, Hedegaard M.
Reduction in stillbirths at term after new birth induction paradigm:
results of a national intervention. BMJ Open. 2014;4:e005785.
3) Statens Seruminstitut. F?dselsstatistik tal og analyser. 2012;
table 2.2. http://www.ssi.dk/~/media/Indhold/DK%20-
%20dansk/Sundhedsdata%20og%20it/NSF/Registre/Fodselsregisteret/f%C3%B8dselsstatistikken2012_vers%204.ashx.
Accessed August 26th
4) Statens Serum Institut. The online Medical Birth Registry.
http://www.ssi.dk/Sundhedsdataogit/Sundhedsvaesenet%20i%20tal/Specifikke%20omraader/Fodsler%20og%20aborter/Fodsler%20og%20komplikationer.aspx
Accessed August 26th
Thank you to the authors for considering my comments to their recent
publication.
I agree with the authors that in real life we often have to rely on
observational studies. Therefore we must allow us self to discuss the
limitations of our analysis to avoid to draw biased conclusions.
Causal inference in non-experimental studies typically requires; that
no unobserved factors confound the relationship bet...
Thank you to the authors for considering my comments to their recent
publication.
I agree with the authors that in real life we often have to rely on
observational studies. Therefore we must allow us self to discuss the
limitations of our analysis to avoid to draw biased conclusions.
Causal inference in non-experimental studies typically requires; that
no unobserved factors confound the relationship between the exposure and
the outcome. Violations of this assumption will lead to biased estimation
of causal effects.(1)
Socio-economic status is one of the most recognized confounders in
medical science and especially relevant when studying stillbirth.
Moreover, confounding by treatment as a result of a better and a more
intensive regime of ultrasonography in early and late pregnancy is hard to
disallow.
Comparing observational data for different countries with different
induction and ultrasonography regimes for pregnant women is not a strong
argument for causal effect.
Considering both strengths and limitations in study design as well as
relevant confounding factors is not normally addressed as being puritan
but considered as timely in scientific practice.
1. Editorial. Associations are not effects. Am J Epidemiol.
1991;133:101-102.
We would like to make a minor correction to the discussion section of
our paper. The quotation from Atroshi et al, regarding false
positive/negative nerve conduction studies in CTS should read "30% false
negative and 18% false-positive"
We wish to make a notation to this article. In all instances
"American Academy of Family Practitioners" should read "American Academy
of Family Physicians."
Thanks to Rikke D. Maimburg for her comments and considerations to
our study on stillbirths.
In real life, we very often have to rely on observational studies in
the attempt to identify and quantify risk factors (causes) of diseases and
deaths. Although the possibility of residual confounding in all such
studies has to be considered, it is in our opinion too puritan to discard
all observational studies in this...
Thanks to Rikke D. Maimburg for her comments and considerations to
our study on stillbirths.
In real life, we very often have to rely on observational studies in
the attempt to identify and quantify risk factors (causes) of diseases and
deaths. Although the possibility of residual confounding in all such
studies has to be considered, it is in our opinion too puritan to discard
all observational studies in this regard. The vast majority of identified
and quantified risk factors have actually been found by observational
studies.
In the present study, we made a regression analysis, accounting for
what we considered to be the most important confounders for the observed
decline. Many risk factors exist for stillbirths, but only a fraction of
these are confounders, which in addition to being risk factors of
stillbirths also should be associated with the secular change in induction
practice.
Thus intrauterine growth restriction and preeclampsia are certainly risk
factors of stillbirth, but had no confounding influence in our study when
we tested for it, probably due the almost constant prevalence of these
conditions through the study period.
The increasing proportion of adipose delivering women, higher
maternal age, fewer post term twin deliveries and the reduced fraction of
smokers, on the other hand, were all confounders and adjusted for.
It was not possible to adjust for number of ultrasound examinations,
and it is true, that the surveillance of post term pregnancies has
improved by time. Our point was, however, that this improvement has also
been implemented in our neighbour countries, without a similar reduction
in stillbirths.
We did not only mention the many circumstances which contributed to
the decline in stillbirths, but also attempted to quantify the
contribution of each of these factors. Thus the detection and abortion of
foetuses with malformations was quantified, the contribution of the
decline in smokers was quantified, and the small influence of the slightly
increasing body mass index and age of delivering women were quantified.
The significance (influence) of twin pregnancies for stillbirths
declined by time, due to more consequent and earlier induction of twin
deliveries by time. The same applies to pregnancies in women beyond 40
years and in women with high body mass index, which have been selectively
induced even earlier in accordance with the new guidelines. Our data
confirmed that these circumstances had a profound declining influence on
stillbirth rates.
So, we still think our data support our conclusion, which never was that
earlier induction was the only contributing factor, but according to our
analysis was the most important contributing factor of all the
investigated circumstances for the dramatic decline in stillbirths.
The significance (influence) of twin pregnancies for stillbirths
declined by time, due to more consequent and earlier induction of twin
deliveries by time. The same applies to pregnancies in women beyond 40
years and in women with high body mass index, which have been selectively
induced even earlier in accordance with the new guidelines. Our data
confirmed that these circumstances had a profound declining influence on
stillbirth rates.
So, we still think our data support our conclusion, which never was
that earlier induction was the only contributing factor, but according to
our analysis was the most important contributing factor of all the
investigated circumstances for the dramatic decline in stillbirths.
I enjoyed reading the paper "Reduction in stillbirths at term after
new birth induction paradigm: results of a national intervention" by
Hedegaard et al with the encouraging message that the mortality rate for
Danish newborns has declined to a historically low number.
The authors' conclusions seem, however, a bit too far-reaching when
they claim that earlier induction has reduced the still...
I enjoyed reading the paper "Reduction in stillbirths at term after
new birth induction paradigm: results of a national intervention" by
Hedegaard et al with the encouraging message that the mortality rate for
Danish newborns has declined to a historically low number.
The authors' conclusions seem, however, a bit too far-reaching when
they claim that earlier induction has reduced the stillbirth rate and may
be self-accountable for up to 15 % of the reduction of stillbirths. The
study by Hedegaard et al. is an observational study and a causal
relationship can therefore not be established. Moreover, the lack of
adjustment for birth defect, intra uterine growth restriction (IUGR),
medical diseases before and during pregnancy, ultrasound scans, and socio-
economic status in analysis may introduce to bias in the risk estimates
due to residual confounding.
The continuing decline in stillbirths in the study period is probably
a result of several concurrent interventions. In particular, the
comprehensive surveillance program introduced during the year 2011 may
relevant. A total of 17 of the 24 Danish maternity wards implemented
routine antenatal surveillance of pregnancies that exceeded 41 weeks of
gestation. This practice included ultrasound monitoring of foetal well-
being as well as cardiotocography and clinical examinations at each visit
after 41 weeks of gestation (the visits are normally scheduled at
gestational age 41+3 and 41+5). This surveillance program is not mentioned
by Hedegaard et al.
The present study provide clear and solid evidence that the
stillbirth rate in Denmark have declined during the study period from 2000
- 2012 but provides little data to support the authors conclusion that
earlier induction is a major explanation for the decline in stillbirths.
We read with great interest the recently published National cohort
study of Hedegaard et al (1). The authors rightly indicate in their
introduction that women with foetal growth restriction or preeclampsia are
at high risk for stillbirth, and that in these women induction before term
is often recommended; these authors also stress that since 2009, Denmark
has had a more proactive policy including early intervention in wome...
We read with great interest the recently published National cohort
study of Hedegaard et al (1). The authors rightly indicate in their
introduction that women with foetal growth restriction or preeclampsia are
at high risk for stillbirth, and that in these women induction before term
is often recommended; these authors also stress that since 2009, Denmark
has had a more proactive policy including early intervention in women with
preeclampsia. However, no data are given in the article about the rates of
preeclampsia, small for gestational age babies, or foetal growth
restriction, although, as stated by the authors, the increased quality of
screening for ultrasound foetal growth and Doppler during the last decade
may have improved the monitoring of foetuses in utero, making it easier to
detect foetal growth restricted foetuses and to induce labour to avoid
foetal death or preeclampsia. Without these data, it is difficult to agree
with Hedegaard et al that "these circumstances are probably of minor
importance for the decrease in stillbirths" from the comparison of Danish
figures with the whole proportion of deliveries after 42 weeks in Sweden,
or the whole stillbirth rate after 37 gestational weeks in Norway. Indeed,
using the ReCoDe ("relevant condition at death") classification for
stillbirth, Gardosi et al confirmed that the most common cause of foetal
death was precisely foetal growth restriction (43.0%) in West Midlands
region of the UK (2) as it is observed worldwide (3), and the incidence of
this condition is probably similar in Denmark. This significant
contribution of foetal growth restriction (and possibly associated
preeclampsia in cases of defective placentation) is all the more plausible
that in the Disproportionate Intrauterine Growth Intervention Trial At
Term (DIGITAT) study (3) comparing the effect of induction of labour with
a policy of expectant monitoring for intrauterine growth restriction near
term in the Netherlands, even in the "expectant monitoring group" labour
had to be induced in as high as 50% of the patients at gestational age 277
(269-283) days [versus 95.6% at gestational age 266 (261-271) days in the
"Induction of labour group"]. Furthermore, taking into account the
possible impact of the message delivered by Hedegaard et al's article in
daily practice, the historical design (and not true intervention design)
of this study, with the inherent limitations, should have been clearly
specified in the clinical message.
1.Hedegaard M, Lidegaard O, Skovlund CW, M?rch LS, Hedegaard M.
Reduction in stillbirths at term after new birth induction paradigm:
results of a national intervention. BMJ Open. 2014;4:e005785.
2.Gardosi J, Kady SM, McGeown P, Francis A, Tonks A. Classification of
stillbirth by relevant condition at death (ReCoDe): population based
cohort study. BMJ. 2005;331(7525):1113-7.
3.Lawn JE, Blencowe H, Oza S et al and Lancet Every Newborn Study Group.
Every Newborn: progress, priorities, and potential beyond survival.
Lancet. 2014;384(9938):189-205.
4.Boers KE, Vijgen SM, Bijlenga D et al. Induction versus expectant
monitoring for intrauterine growth restriction at term: randomised
equivalence trial (DIGITAT). BMJ. 2010;341:c7087.
Thanks to Jette Clausen (JC) and Eva Rydahl (ER) for their considerations on our study on stillbirths.
JC and ER suggest our interpretation being "overly optimistic" due to our observational design. But again, observational studies have identified a long list of causes of diseases, be it lung cancer among smokers, venous thrombosis among users of hormonal contraception, greenhouse gas emissions as a cause of global...
Thanks to Lionel Carbillon, Claire de la Hosseraye & Arsene Mekinian for their interest in and comments to our paper on stillbirth reduction in Denmark with a more proactive induction practice.
No doubt, that the improved ultrasound monitoring of pregnancies at term is expected to have decreased the stillbirth rates all over the industrialised world. It is also true, that the stillbirth rates may be higher...
This is a fascinating study into infections during onset and progress of RA.
I have recently been investigating potential roles for herpes viruses, especially cytomegalovirus (CMV), in a series of infectious-like outbreaks seen within the UK over many years. These outbreaks lead to increased deaths and hospital admission for a range of medical conditions which include allergy[1-9]. There are several areas of pot...
A call for humility on the Reduction in stillbirths at term after new birth induction paradigm
Hedegaard et al state in their recent article: Reduction in stillbirths at term after new birth induction paradigm: results of a national intervention, that they 'see no reason why a similar, more proactive induction paradigm could not be implemented in other countries' (1). Their observational study design limits dra...
Thank you to the authors for considering my comments to their recent publication.
I agree with the authors that in real life we often have to rely on observational studies. Therefore we must allow us self to discuss the limitations of our analysis to avoid to draw biased conclusions.
Causal inference in non-experimental studies typically requires; that no unobserved factors confound the relationship bet...
We would like to make a minor correction to the discussion section of our paper. The quotation from Atroshi et al, regarding false positive/negative nerve conduction studies in CTS should read "30% false negative and 18% false-positive"
Conflict of Interest:
None declared
We wish to make a notation to this article. In all instances "American Academy of Family Practitioners" should read "American Academy of Family Physicians."
Thank you
Conflict of Interest:
None declared
Thanks to Rikke D. Maimburg for her comments and considerations to our study on stillbirths.
In real life, we very often have to rely on observational studies in the attempt to identify and quantify risk factors (causes) of diseases and deaths. Although the possibility of residual confounding in all such studies has to be considered, it is in our opinion too puritan to discard all observational studies in this...
Dear Sirs,
I enjoyed reading the paper "Reduction in stillbirths at term after new birth induction paradigm: results of a national intervention" by Hedegaard et al with the encouraging message that the mortality rate for Danish newborns has declined to a historically low number.
The authors' conclusions seem, however, a bit too far-reaching when they claim that earlier induction has reduced the still...
We read with great interest the recently published National cohort study of Hedegaard et al (1). The authors rightly indicate in their introduction that women with foetal growth restriction or preeclampsia are at high risk for stillbirth, and that in these women induction before term is often recommended; these authors also stress that since 2009, Denmark has had a more proactive policy including early intervention in wome...
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