BF: Artificial Nipple and Duration of Breastfeeding (2008)
Dulon M, Kersting M, Schach S. Duration of breastfeeding and associated factors in Western and Eastern Germany. Acta Paediatr 2001; 90: 931-935.
PubMed ID: 11529545To examine the differences in breastfeeding behaviors and infant nutrition between former Western and Eastern Germany.
Between March and May 1997, women delivering in specific two-week period assigned to each hospital.
Infant birth weight <2,500g; Gestational age <37 weeks; admission to neonatal care unit; non-German-speaking; no telephone; late submission of written consent.
Recruitment
177 out of 345 randomly selected hospitals participated in study.
Design
Prospective longitudinal study
Statistical Analysis
Chi-square or Fisher's exact test (comparisons between groups); Odds Ratio (OR) and confidence intervals (CI) to estimate Relative Risk; Multiple Logistic Regression; P<0.05 significant.
Timing of Measurements
- Basic telephone interview 14±2 days post-partum (demographics, breastfeeding practices)
- Mailed questionnaires at two, four, six, nine and 12 months post-partum (infant feeding practices)
- Telephone interview to those who had stopped breastfeeding since the last questionnaire (reasons for stopping).
Dependent Variables
- Long (≥ four months) vs. short-term (< four months) breastfeeding
- Reasons for giving up breastfeeding (15 items, five-point Likert scale)
Independent Variables
Breastfeeding status assessed by WHO recommendations, combined into:
- Breastfeeding only(exclusive or predominant, i.e. plus liquids)
- Mixed (plus formula or weaning food)
- Non-breastfeeding (no breastfeeding).
Control Variables
Factors significant in the univariate analysis were included in the multivariate model together with the exposure variable, location of maternal upbringing.
Initial N
3,294 eligible women
Attrition (final N)
1,717 women completed initial; telephone interview; data in report from 1,593 mothers (80.3% Western and 19.7% Eastern Germany)
Age
89.9% and 66.7% of West and Eastern German women, respectively <25 years of age
Ethnicity
Eastern20% and Western 80% German descent
Other relevant demographics
33.9 and 23.3% Western and Eastern women, respectively >10 years education
Location
Research Institute of Child Nutrition, Dortmund, Germany
Factors associated with short-term breastfeeding, after adjusting for confounders (not significantly different between Western and Eastern women):
Variables | OR | 95% CI | Statistical Significance of Group Difference |
Supplementary feeding during first three days |
2.92 1.80 |
1.65-5.24 1.38-2.35 |
P=0.003 P=0.001 |
Breastfeeding problems during first 14 days | 2.41 | 1.88-3.10 | P=0.001 |
Pacifier used during first 14 days | 1.41 | 1.06-1.89 | P=0.020 |
Also associated with shorted breastfeeding duration: Maternal age ≤ 25 years; single parent; low maternal education; partner's negative attitude towards breastfeeding.
Not the geographical location, (East vs. West) but the different distribution of risk factors (social, cultural) was associated with short-term breastfeeding.
Anthropometrics not reported (factors affect breastfeeding duration or success: Maternal (pre-pregnancy) weight/BMI, gestational weight gain, post-partum weight retention).
Quality Criteria Checklist: Primary Research
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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) | N/A | |
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) | N/A | |
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? | 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.) | Yes | |
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? | N/A | |
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? | 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? | 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? | N/A | |
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? | No | |
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? | 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 | |