Health Disparities

HD: Effectiveness of Nutrition Intervention Methods (2010)


Memmott MM, Bonuck KA. Mother's reactions to a skills-based breastfeeding promotion intervention. Matern Child Nutr. 2006 Jan; 2 (1): 40-50.

PubMed ID: 16881913
Study Design:
Randomized Controlled Trial
A - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To determine whether and how participation in a breastfeeding promotion intervention study affected mothers' infant feeding choices and if they would recommend such an intervention to others.

Inclusion Criteria:
  • Prenatal patients
  • Patient at two Bronx, New York health centers
  • Provided informed consent.
Exclusion Criteria:
  • Patients who did not agree to participate or provide informed consent
  • Non-pregnant women and men
  • Patients at non-participating health centers
  • Mothers of twins
  • Women who miscarried or terminated their pregnancy.
Description of Study Protocol:


Bi-lingual English–Spanish study staff recruited participants from the two participating health centers.


Randomized, controlled trial


A study lactation consultant met individually with Intervention group women twice prenatally, attempted postpartum hospital and home visits and was available for phone consultation up to 12 months. The initial prenatal visit focused on trust, support and education. The second visit addressed postpartum expectations and specific breastfeeding techniques. Post-natal hospital and home visits focused on breastfeeding technique, complications and pump use. If later contact was made, they tended to focus on expressing and storing milk, fatigue, nursing in public, returning to school or work and supplementing. The lactation consultants helped mothers gain support from their families, schools, workplaces and health care providers.

Control group women received the standard care provided by the health center. This included routine prenatal visits with an obstetrician/gynecologist or family physician. Control group women had no contact with the lactation consultants.

Statistical Analysis

Notes and transcripts were entered into N6 (N6, Qualitative Data Software, QSR International: Melbourne, Australia), a qualitative data management and analysis program. 


Data Collection Summary:

Timing of Measurements

Participants completed a baseline interview, which included demographics, previous breastfeeding experience, intention to breastfeed and breastfeeding knowledge. Eight post-natal follow-up interviews were scheduled for at one, two, three, four, six, eight, 10 and 12 months postpartum. After the interviewer completed the 12-month "check in" data collection with a woman, she was then asked if she would complete the exit interview. Intervention group women were asked about their experience meeting or working with the study mother-baby specialist.  They were asked if they would use or recommend these services in the future. Both intervention and control participants were asked whether being in this study influenced how they fed their baby. 

Dependent Variables

  • Post-natal feeding practices
  • Attitude towards breastfeeding and Mother-Infant Specialist.

Independent Variables

Contact with Mother-Infant Specialist (Lactation Consultant).


Description of Actual Data Sample:
  • Initial N: 382 women (N=188 intervention, N=194 control)
  • Attrition (final N):
    • 304 women (N=145 intervention, N=159 control)
    • Exit Interview Sample (N=21).
  • Age:
    • Mean age (±SD)
    • Total Sample: 25.3±6.13
    • Exit Interview: 25.6±6.01.
  • Ethnicity:
    • Total Sample: Black 142 (37%)      
      • Exit Interview: 11(52%)
    • Total Sample: Hispanic 210 (55%)
      • Exit Interview: Eight (38%)
    • Total sample: Other 30 (8%)
      • Exit Interview: Two (10%).
  • Location: Bronx, New York.


Summary of Results:

Key Findings


Comparison of total and exit interview samples
Variables Total Sample
Exit Interview
Women (N=21)
Prenatal feeding intent

Formula only: 36 (9%)

Mixed formula/breast milk: 181 (47%)

Breast milk only: 118 (31%)

NA: 47 (12%)

Formula only: 1 (5%)

Mixed formula/breast milk: six (29%)

Breast milk only: 10 (48%)

NA: Four (19%)

Post-natal feeding at two months

Formula only: 118 (41%)

Mixed formula/breast milk: 128 (44%)

breast milk only: 44 (15%)

Formula only: Seven (33%)

Mixed breast milk/formula: 10 (48%)

breast milk only: 3 (14%)

Post-natal feeding at three months

Formula only: 130 (48%)

Mixed formula/breast milk: 116 (42%)

Breast milk only: 37 (10%)

Formula only: Eight (38%)

Mixed formula/breast milk: 10 (48%)

Breast milk only: Two (10%)





Author Conclusion:

Qualitative exit interviews with participants in a randomized controlled trial of a breastfeeding promotion intervention elicited feedback on the study's impact upon infant feeding practices and participants' study experience. Intervention participants credit the lactation consultants with helping them to initiate and continue breastfeeding by providing encouragement and teaching breastfeeding skills. Control group women, compared with intervention women, were less aware that they were participating in a research study. Control group women expressed interest in receiving more education and support with regards to breastfeeding. 

Limitations of this exit interview study include a bias towards women who were able to be contacted at 12 months postpartum. Only 50% of women eligible for post-natal interview completed a 12-month follow-up indicating a low retention rate. This low retention rate was due to frequent moves and phone disconnections in this socio-economically disadvantaged sample.  This study is based on a small convenience sample and therefore may not be representative of the RCT participants or the patients at the Bronx health clinics. Also, when asked about aspects of the study that were unhelpful, the lack of criticisms about the study suggests a possible censoring of any negative reactions to the study. 

Overall, this study showed a significant increase in breastfeeding duration and intensity. The intervention group had greater continued breastfeeding through week 20 and feeding of ≥50% breast milk through week nine (45.8% vs. 33.1% for controls, P<0.030).

Funding Source:
Government: US Maternal and Child Health Bureau, the US Agency for Healthcare Policy and Research, and the US Department of Agriculture
Reviewer Comments:
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? ???
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? No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? No
  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.) No
  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? Yes
  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? N/A
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