EAL

HD: Effectiveness of Nutrition Intervention Methods (2010)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To examine the effect of a peer counseling program on breastfeeding initiation and duration in an unselected WIC population presenting to nine different health departments in rural West Tennessee.

Inclusion Criteria:

Women between six weeks and six months post-partum
Had registered ante-partum for WIC at a study clinic in West Tennessee
- Study clinics had to see at least 25 pre-natal patients during the study period
- Had to be within a 90-minute drive from the university
Present to clinic between December 1996 and March 1997.

Exclusion Criteria:

Women who had not been seen ante-partum by WIC clinic.

Description of Study Protocol:

Recruitment

All clients who met the study criteria were sent a questionnaire.

Design

Cross-sectional
32 item questionnaire sent to study participants
- 10 multiple choice items on the home and work situation, previous infant feeding experiences and delivery and hospital experience
- 20 additional items for women who attempted to breastfeed
Chart review performed to gather demographic data, delivery method and the number, timing and type of interaction with the nutritionist and the peer counselor.

Intervention

Use of a peer counselor in the WIC program for pregnant and ante-partum women
Peer counselors must have previously breastfed and have been on WIC
Peer counselors have had 56 hours of continuing education and had individual training with the program coordinator
At the time of the study there were seven peer counselors serving 11 out of 19 health departments in West Tennessee.

Peer Counseling Program

Peer counselors saw a client at least once prior to delivery and at each post-partum WIC visit if they were breastfeeding
Counselors' home phone were available to encourage post-partum contact
Peer counselors used a questionnaire at the first ante-partum visit, then sessions were based on individual need
Standardized assessment tool designed to identify breastfeeding problems was used post-partum.

Statistical Analysis

Hypothesis: Women in the peer counselor (PC) group had higher breastfeeding incidence and duration rates than women in the non-peer counselor (no-PC) group
PC group comprised of women who had access to a peer counselor and actually saw one prenatally (N=156)
No-PC group comprised of women who had no access to a peer counselor or did have access but did not see the peer counselor (N=135)
Student's T-test used for testing differences between groups for ordinal and continuous variables
Chi-square test used for categorical variables
Multiple step-wise logistic regression used to identify factors associated with breastfeeding initiation and duration at six weeks for women in the PC group
All tests were two-sided and α=0.05, pre-selection phase for multivariate analysis α=0.10.

Data Collection Summary:

Timing of Measurements

Data collection used historical data found in medical records
Questionnaire data obtained via client recall about delivery and breastfeeding.

Dependent Variables

Breastfeeding initiation: Defined as any attempt at breastfeeding
Breastfeeding duration: Defined as breastfeeding one or more times daily at six weeks.

Independent Variables

Having participated in the peer counseling program.

Control Variables

Age
Race
Marital status
Education
Parity
Working outside the home
Smoker
C-section
Medical complications, pregnancy or infant
Initial infant feeding decision
Previous experience breastfeeding
Perceived family support
Perceived provider support.

Description of Actual Data Sample:

Initial N: 293 women
Attrition (final N): 291 women (N=156 PC group, N=135 no-PC group)
Age: Mean age of 22, range from 14 to 43
Ethnicity: 66 of 291 (23%) were categorized as African American
Other relevant demographics:
- 81 of 291 (28%) women were smokers
- 151 of 291 (52%) women were single
- 234 of 291 (80%) were on Medicaid
- 115 of 291 (40%) had less than 12 years of education
- 123 of 291 (42%) were primiparitous; overall rate of breastfeeding initiation was 44%, continuation rate at six weeks was 20%
- PC vs. no-PC groups (statistically significant differences, P<0.05)
- PC group had a higher percentage of women less than 20 years old and African American
- PC group had a higher percentage of multiparous women with previous breastfeeding experience
- No-PC group had a higher percentage of infants with medical complications
Location: West Tennessee.

Summary of Results:

Key Findings

Significantly more women in the PC group initiated breastfeeding (53% vs. 33%, P<0.01)and left the hospital breastfeeding compared to the no-PC group (44% vs. 26%, P<0.01)
Significantly more women in the PC group continued to breastfeed their babies at six weeks or longer (26% vs. 13%, P<0.01)
No statistical difference of breastfeeding duration between groups when only breastfeeding initiators were compared.

Other Findings

Factors significantly associated with breastfeeding initiation among entire sample (adjusted odds ratio, 95% CI)
- Perceived family support (3.26, 2.67 to 3.98)
- Perceived provider support (2.05, 1.64 to 2.58)
- Initial infant feeding decision to breastfeed (7.08, 5.59 to 8.95)
Factors significantly associated with breastfeeding continuation at six weeks (adjusted odds ratio, 95% CI)
- Contact with a peer counselor (2.78, 1.31 to 5.91)
- Perceived provider support (2.05, 1.64 to 2.58)
- Initial infant feeding decision to breastfeed (4.45, 2.08 to 9.51).

Author Conclusion:

Demonstrates efficacy of a peer counselor program in both improving breastfeeding initiation and duration in a rural, low-income population
Most powerful influence on initiation and duration was initial infant feeding decision
Main strength of the PC program may lie in supporting women to following through with their breastfeeding decision, rather than attempting to change initial infant feeding decision of undecided or bottle.

Funding Source:

University/Hospital:

Department of Family Medicine, McMaster University, Ontario, Canada

Reviewer Comments:

No blinding used
Clients had access to peer counselors and nutritionists at clinic visit, data for visiting nutritionist was not given, unclear what effect this had on the study. For example, clients may not have seen a peer counselor and been assigned to the no-PC group but did see the nutritionist.

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?		No
	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?	No
3.	Were study groups comparable?		No
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	N/A
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	No
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	No
	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?	Yes
	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.)	No
	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?	N/A
	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?	N/A
	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?	N/A
	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.)	N/A
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	No
	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?	N/A
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	Yes
	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)?	N/A
	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?	No
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