Case-control study is appropriate but the intervention needs more justification.
This is with respect to the study investigating the reduction in SIDS due
to pacifier use. Pacifier use has been associated with vast advantages as
well as disadvantages. It is comparable to that of a double edged sword.
It is interesting that many mothers prefer to use pacifiers with their
kids instead of breast feeding. Because studies have shown that it tends
to reduce the duration of breast feeding in infants. For instance, a
prospective cohort study showed that the use of pacifier reduced the
duration of breast feeding.(1) But being a cohort study, there could be a
potential possibility for “Hawthorne effect” where in the intervention or
the attention of the researcher in itself has the potential to cause
altered favorable or detrimental behavior. So it raises a question
whether a case-control study performed by these authors is suitable for
this situation than a cohort study. Although a cause and effect
relationship is hard to bring about in a case-control study, the fact that
it does account for only past feeding habits and has no effect on their
feeding behavior is a matter of advantage.
Although the research demonstrated a reduction in incidence of SIDS after
pacifier use, it is mainly due to the ability of the pacifier to act as an
impediment to the kid rolling over to a prone position when unobserved.
And prone position has been shown to cause “less flexibility in heart rate
variability, reduced arousal and waking ability and poor ventilatory and
airway protective responses”.(2) Hence it would be practically prudent to
introduce a public health intervention whose advantages clearly outweigh
If the chief means of occurrence of SIDS is argued to be due to hypoxia,
than the immediate risk factor appears to be “prone position” of the kid,
wherein the pacifiers help to prevent the kids from going to this
vulnerable position. But other potential causes for SIDS in a kid such as
anemia and placental abruptions(3) and even anaphylaxis has also been
proposed. (4) Hence the introduction of pacifier is only helpful to remain
the kid in supine position. If the case-control study has matched for the
above confounding factors than effectiveness of the intervention could be
The impact of the use of pacifier on the health of the kid in general and
the oral health specifically is still a matter of concern. Dental decay,
occlusal changes, persistence of sucking habit into early adulthood and
change in breathing patterns have also been recognized. Hence this article
is ambiguous to a certain extent that it is providing biased information
for the public. Although the use of pacifiers could potentially reduce the
incidence of the kid going to the prone position, the disadvantages and
the after effects of the use of pacifiers have to be considered for
healthy public health intervention. Hence investigations and research into
an intervention or device at positioning the kid in the supine position
should be carried out rather than utilizing other easier but destructive
forms of intervention.
1. Vogel A, Hutchinson B, Mitchell E. The impact of pacifier use on
breastfeeding: A prospective cohort study. Journal of Paediatircs and
Child health 2000; 37:58-63.
2. Galland B, Taylor B, Bolton D. Prone versus supine sleep position:
A review of the physiological studies in SIDS research. Journal of
Paediatircs and Child health 2002;38:332-338.
3. Klonoff-Cohen SH, Srinivasan PI, Edelstein LS. Prenatal and
intrapartum events and sudden infant death syndrome. Paediatric and
4. Buckley MG, Variend S, Walls AF. Elevated serum concentrations of
b-tryptase, but not atryptase, in Sudden Infant Death Syndrome (SIDS). An
investigation of anaphylactic mechanisms. Clinical and Experimental
Competing interests: No competing interests