EAL

BF: Artificial Nipple and Duration of Breastfeeding (2008)

Citation:

Howard CR, Howard FM, Lanphear B, Eberly S, deBlieck EA, Oakes D, Lawrence RA. Randomized clinical trial of pacifier use and bottle-feeding or cupfeeding and their effect on breastfeeding. Pediatrics. 2003, 111: 511-518.

PubMed ID: 12612229

Study Design:

Randomized Controlled Trial

Class:

A - Click here for explanation of classification scheme.

Quality Rating:

POSITIVE: See Quality Criteria Checklist below.

Research Purpose:

To evaluate the effects of pacifier use and in-hospital cup-feeding and bottle-feeding on breastfeeding.

Inclusion Criteria:

Women who intended to breastfeed their infants for at least four weeks
Uncomplicated, singleton pregnancies
Undecided or wanted their infants to use a pacifier.

Exclusion Criteria:

Admission to neonatal intensive care unit on delivery
Mother decided not to breastfeed
Mother declined participation after delivery
Not meeting inclusion criteria.

Description of Study Protocol:

Recruitment

Initial prenatal contacts made and again when admitted to hospital for delivery.

Design

Randomized clinical trial.

Blinding used

Investigators, research assistants, and nurses conducting postpartum interviews blind to group assignment.

Intervention

Upon mothers' admission to the hospital, unborn infants were randomly assigned to: 1) Cup or bottle supplemental feeding (in-hospital) group; and 2) Early (two to five days) or late (more than four weeks) pacifier (as mode of comfort) introduction group for a total of four intervention groups:

Cup/early pacifier
Cup/late pacifier
Bottle/early pacifier
Bottle/late pacifier.

Statistical Analysis

ANOVA
Chi-square analyses
Kruskal-Wallis tests
Kaplan-Meir, intention-to-treat analyses
Wilcoxon test
Cox proportional hazards model
Adjusted logistical regression.

Data Collection Summary:

Timing of Measurements

After delivery, infants' feeding records were labeled with appropriate supplemental method (cup or bottle). Nurses documented reason for supplemental feeding (volume of feeding not recorded for entire sample, only for 100 supplemented infants in each group). Feedings were administered by the nurse assigned to care for the mother-infant pair while in hospital.

Before discharge, mothers were interviewed by a research assistant about demographics, plans for infant care, feeding experiences, etc. Families were instructed about alternative methods of infant soothing, pacifier use in respective intervention group (early or late introduction). Pacifiers were provided to families in early group upon discharge; for the late group, pacifiers were mailed during fourth week postpartum.

Mothers were interviewed via telephone at two, five, 10, 16, 24, 38 and 52 weeks by a nurse. Prenatal and perinatal health data and demographics were obtained from infant birth certificates and mother and infant medical charts.

Dependent Variables

Cessation of overall, full and exclusive breastfeeding
Breastfeeding-associated maternal and infant problems
Effects of intervention in subgroups of women (primiparas, low education, C-section delivery).

Independent Variables

Assignment to one of four intervention groups (supplemental feeding/pacifier introduction): Cup/early pacifier, cup/late pacifier; bottle/early pacifier; bottle/late pacifier.

Control Variables

Timing of measurements
Length of intervention
Instructions provided to mothers
Nursing care in hospital
Encouragement of breastfeeding.

Description of Actual Data Sample:

Initial N: 700 mother-infant pairs

Attrition (final N): 686 mother-infant pairs: 169 in bottle/early pacifier, 167 in bottle/late pacifier, 185 in cup/early pacifier, 179 in cup/late pacifier

Age: 29.0±5.3 years

Ethnicity: 87% white

Other relevant demographics: 14.3±2.1 years education; 39% primiparous

Anthropometrics: Mother's anthopometrics not reported; infant birth weight 3,550±462g

Location: University of Rochester School of Medicine, Rochester, NY.

Summary of Results:

6% (N=481 of 700) infants participated in supplemental feeding intervention:33% for medical reasons, 51% maternal request, 16% no documentation of supplementation reason. Mothers of infants who received supplemental feedings in the hospital were more likely to be primiparous (41% vs. 35%), receive federal assitance (17% vs. 9%), to be breastfeeding for the first time (49% vs. 39%) and to deliver by C-section (20% vs. 6%). Among supplemented infants, compliance to feeding assignement was 89% in bottle and 93% in cup groups.

Supplemental feedings, regardless of method, had a detrimental effect on breastfeeding duration when compared to no supplemental feeding in the hospital.

Adjusted Effects on Breastfeeding Duration, HR (95% CI)

	Bottle-supplement	P	Early pacifier	P	Received supplement	P
Duration Exclusive Breastfeeding	1.06 (0.88-1.27)	0.54	1.09 (0.94-.27)	0.26	1.49 (1.23-1.80)	<0.0001
Duration of Full Breastfeeding	1.01 (0.84-1.22)	0.88	1.04 0.89-1.21)	0.64	1.50 (1.24-1.81)	<0.0001
Duration of Overall Breastfeeding	0.92 (0.76-1.12)	0.42	1.22 1.03-1.44)	0.02	1.53 (1.24-1.89)	<0.0001

When more than three supplemental feedings were received, cup feeding significantly improved exclusive (P<0.0001) and full (P=0.0002) breastfeeding duration. Significant differences in total volume of non-breast-milk supplements consumed by cup (67±67ml) and bottle (121±167ml) infants, though group assignment did not affect type of supplement (breast milk vs. formula) offered to infants continuing to receive supplements after discharge.

Pacifier use (vs. no use) at four weeks postpartum caused a significant decrease in exclusive breastfeeding among those infants exposed to pacifiers (pacifier: OR 1.5, CI 1.0-2.0, P=0.03; bottle: OR 1.4, CI 0.9-2.1, P=0.09; supplement: OR 2.0, CI 1.3-2.9, P=0.001), but did not affect full or overall breastfeeding. Early pacifier use significantly shortened overall (not full or exclusive) breastfeeding duration when adjusted for other factors and for effect of supplemental feed and method (HR 1.22, CI 1.03-1.44, P=0.02).

The most significant predictor of all types of breastfeeding duration was receipt of supplemental feedings while in the hospital (P<0.0001). Method of feeding and pacifier introduction were not as potent predictors, although pacifier introduction became more important among primiparas (P=0.004).

Author Conclusion:

Pacifier use in the first four weeks of life lessened the likelihood of exclusive breastfeeding at one month; early pacifier introduction as compared with later introduction had a negative impact on overall breastfeeding duration.

Cupfeeding (vs. bottle-feeding) was a better way to provide supplemental feedings to breast-fed infants; cupfeeding benefited mother-infant pairs for infants delivered by C-section as well as those infants who received more than two supplemental feedings.

This study confirms the importance of recommendations made in the Baby Friendly Hospital Initiative.

Funding Source:

Government:

Bureau of maternal and child health

Reviewer Comments:

Breast-milk output was not measured. Mothers' anthropometrics, infant growth and mothers' perceived difficulty breastfeeding were not reported.

Quality Criteria Checklist: Primary Research
Relevance Questions
	1.	Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)	Yes
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	Yes
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	Yes
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	Yes

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	Yes
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
2.	Was the selection of study subjects/patients free from bias?		Yes
	2.1.	Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?	Yes
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	Yes
	2.4.	Were the subjects/patients a representative sample of the relevant population?	Yes
3.	Were study groups comparable?		Yes
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	Yes
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	Yes
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	Yes
	3.4.	If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?	N/A
	3.5.	If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)	N/A
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
4.	Was method of handling withdrawals described?		Yes
	4.1.	Were follow-up methods described and the same for all groups?	Yes
	4.2.	Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)	Yes
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	Yes
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
5.	Was blinding used to prevent introduction of bias?		Yes
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	Yes
	5.2.	Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)	Yes
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	N/A
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	N/A
	5.5.	In diagnostic study, were test results blinded to patient history and other test results?	N/A
6.	Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?		Yes
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	Yes
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	N/A
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	Yes
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	Yes
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	Yes
	6.6.	Were extra or unplanned treatments described?	N/A
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	Yes
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
7.	Were outcomes clearly defined and the measurements valid and reliable?		Yes
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	Yes
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	Yes
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	Yes
	7.5.	Was the measurement of effect at an appropriate level of precision?	Yes
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	Yes
	7.7.	Were the measurements conducted consistently across groups?	Yes
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		Yes
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	Yes
	8.2.	Were correct statistical tests used and assumptions of test not violated?	Yes
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	Yes
	8.4.	Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?	Yes
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	Yes
	8.6.	Was clinical significance as well as statistical significance reported?	Yes
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	Yes
9.	Are conclusions supported by results with biases and limitations taken into consideration?		Yes
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	Yes
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes