The Effect of Breastfeeding on  Children’s Cognition

Alghamdi

Comparative Analysis

Research Question what are the effects of breastfeeding on children’s cognition?

This analysis is intended to summarize the two studies of interest and attempt to answer the research question.

Study one: Breastfeeding and child cognitive outcomes

Study two: The effect of breastfeeding on child development at 5 years: A cohort study

Article #1 Summary Conducted by: Jiang, M., Foster, E., & Gibson-

Davis

Purpose: To investigate the the effects of breastfeeding duration and initiation on children’s cognition (perception).

This study took into account previous studies, and it intended to discover the deficiencies that other studies have on the same topic area.

This study focused on confounding variables that can intervene with results.

Article # 1

Summary(Methodology)

Design

The method used is correlational study since it studied the relationship between breastfeeding and cognition. There were 3,271 participants selected from The Child Development Supplement(CDS).

Materials

Tests

1-Woodcock Johnson Psycho-Educational Battery-Revised(WJ-R), which examines cognitive abilities in different areas, such as present progress position and proficiency in math and literacy(Reading).

2-Wechsler Intelligence Scale for Children-Revised (WISC-R) tests, which examines children’s capability to deal with information in memory( working memory).

Article # 1

Summary(Methodology)

Materials(Continue)

The Child Development Supplement(CDS)

is a part of The Panel Study of Income Dynamics (PSID). The participants and their families where selected from CDS. Also, CDS provides information concerning children and their families, such as cognitive abilities, children’s families and neighborhood conditions (Health).

1997 CDS interviews

Previous literature

CDS Data

Article # 1 (Methodology)

Data collection procedures Variables1-Cognition data were collected from tests mentioned. 2-Breastfeeding initiation and period are the independent variables and were collected from 1997 CDS interviews. Breastfeeding can be divided into four groups: not once breastfeed, less that 6 months, between 7 months and year and more than a year. 3- Confounding variables were collected from lit review, CDS and PSID. There are three groups of confounding variables:

Article # 1 (Methodology)

A-Children confounding variables

B-Mothers confounding variables, such as IQ scores taken from 1997 CDS, education and age.

C-Family confounding variables, such as income since the child birth.

Note: there are many confounding variables that had been investigated. However, there is no space to mention them here.

Article # 1 (Methodology)

Data analysis Procedures

Propensity Score Matching is ,According to Jiang et al. ( 2011) ,“ the conditional probability of assignment to treatment given a set of covariates” Calculating Propensity Score for breastfeeding initiation.

Calculating Propensity Score for breastfeeding period

Used Imbens method to investigate the relation between breastfeeding and cognition.

Using a multinomial logic model to calculate propensity of each group period of time.

Ordinary regression is used.

Article # 1 (Methodology)

This study is based on interviews. However, there were multiple incidents that data was missing

The procedures used is

Imputations(MI)

IQ measures taken from 1972 PSID interview.

Article # 1 Summary Results

Data was collected on the sample from the1997 Interviews.

Children

Ages: range from 4 months- 15 years. Average age is

Seven and half years old.

Gender: 50% females.

Ethnic Group: 40% were African American.

Order: 8% were the first child

15% were born preterm.

Article#1SummaryResults(continue)

Children who breastfed achieved high scores on the tests(WJ-R and WISC-R).

Children were white, less likely to be born preterm.

Mothers who breastfed tended to be older than mothers did not breastfeed, achieved high scores on IQ and education.

Mothers who breastfed are more likely to be married. Also, their income is higher comparing to never have breastfed.

Article#1SummaryResults

The effect of breastfeeding initiation.

Children who were breastfed achieved higher scores on tests(2002).

Children achieved higher scores on “applied problems” than those who had not been breastfed.

Article#1SummaryResults

The effect of breast feeding period

The study analysis indicated that there was not a linear correlation between children’s cognitive abilities and breastfeeding period.

Children who were breastfed for 1-6 months showed the same results as children who were breastfed more than 6 months.

Children who were breastfed for 1-6 months achieved higher scores only on ”applied problems” compared to children who were never breastfed.

Example: Concerning comprehension, children who were never berstfed achieved 98.1 and children who were breastfed for 12 months achieved 96.7

Article#1Discussion Literature review showed children who were

breastfed achieved higher scores on cognitive tests than children who drank milk formula. However, higher scores on cognitive tests can result from other factors, such as the mother’s traits.

A study claimed that there is no big difference between children who were breastfed longer than children who were never breastfed. In fact, the study claimed that children who were breastfed more that six months, their outcomes did not have significant effect.

Higher cognitive abilities are best seen when children are breastfed during the first six months. After six months passed, breastfeeding is less associated with high cognitive scores.

Article#1 Discussion Limitations

1-Data collected regarding breastfeeding was mostly dependent on the memory of mothers.

2-when conducting supplemental analysis, investigators found almost identical effects.

3-Investigators were unable to eliminate mothers’ bias in recalling on breastfeeding

4-The study is considered not exclusive since its based on observational data. For instance, some studies stated that some children are still breastfed after 6 months.

Discussion

Limitation (continue)

Since it is an observational study, random assignment was not applicable in this study. In fact, the study may be affected by selection effect. Thus, regression was used. However, it is restricted on some aspects. In this case, score propensity was used.

Propensity score was used to regulate the confounding variables. The study claimed that it considered a broad range of covariates based on previous lit review.

Discussion Furthermore, some cognition results, such as

applied problems, are very strong in relation to breastfeeding. However, other results, such as WISC test, are based on sensitive analysis, which means the tests results are sensitive. When using other correction methods, the the latter results were not important.

Even though there are a lot of advantages of breastfeeding on children and their mothers alike, mothers should not be treated like they do not care about their children’s cognition development. In fact, mothers should be allowed to breastfeed whenever they want if needed.

Discussion

The study stated that public health considered the breastfeeding is less significant than other aspects that can affect children’s cognitive abilities, such as penury. As a result, in order to improve children’s cognitive development, it is more important to focus on other factors that may result in putting children in danger.

Quality Criteria

Objectivity : The study had been done by a group of researchers. So bias would be considered of no relevance. Also, the study took into account different confounding variables that may falsely attribute the relationship between the variables of main interests.

Reliability: Reliability means the results will be the same if the same instruments were used. In this case, I believe the results may vary based on the confounding variables that are of most concern to the researchers.

Validity : Had the study measured what it was supposed to measure? In fact, the research question was if there was a relationship between breastfeeding duration and initiation on children’s cognition development. After the conduction of the study, it was apparent that there was no significant effect of breastfeeding duration and initiation on children’s cognition.

Quality Criteria(continue)

Representative sampling

The sample chosen in this study was taken from a Child Development Supplement(CDS), which selected participants randomly.

Replication

Any study that cannot be replicated is of no value. In this case, the study can be replicated by using different people and examining the same variables. In this case, to replicate the results , a researcher can select another group of participants and examine the same variables: confounding variables stated in the study, breastfeeding period and initiation as independent variables and children cognition.

Theoretical perspective

The theoretical perspective of this study is cognitive developmental theory.

The cognitive theory is concerned with cognitive development in cognition with biological and social factors

Cognitive development applies to this study for the reason below:

This study is intended to measure cognitive development in children by duration and initiation of breastfeeding. In other words, how children develop cognitively.

Article #2: The effect of breastfeeding on

child development at 5 years: A cohort study

Summary

Conducted by: Pj Quinn, M O’callghan, GM William, Jim Najman, MJ Anderson and W Bor.

Hypotheses is, according to Quinn and et al.(2001), “duration of breastfeeding would have direct beneficial effects on child development at 5 years and that this effect would be independent of social and family influences.”

Design The study is correlational because it studies the relationship between breastfeeding, which is an independent variable, and another variable is cognition development.

Participants3880 children (1842 females and 2038 males). Materials Questioners Peabody Pictures Vocabulary Test Revised(PPVT-R)

is Standardized test to measure oral intelligence. Rand health survey -Follow up surveys

Methodology

Data collection techniques

When the babies were age 6 months, questioners were given to the mothers, which includes questions about the mothers’ social and psychological aspects and were inquired for how long they had breastfed according to 6 group periods.

Confounding variables

Mothers’ relationships with their children. For instance, if they had talked and played with them. Also, if they has smoked during pregnancy.

Mothers experiencing anxiety and depression during 6 months and 5 years questionnaires and after delivery.

Methodology At 5 years

Children were asked to take the PPVTR-R test. Children with diseases concerning the neuron system were eliminated.

Confounding variables at 5 years Follow up:

Biological confounding variables were collected, such as gender of the child, age, weight at birth, surgery history ..etc.

Other confounding variables regarding children’s mothers, such as whether they are married or not, speak English, their first experiences and knowledge of pregnancy, if they had smoked…etc.

Note: there are other confounding variables that had been addressed.

Methodology

Data analysis

Analysis of Variance was used to investigate the variation in PPVT-R results in each period of breastfeeding.

Confounding variables were addressed for each child and and also PPVT-R results.

Linear regression was used if the variables in PPVTR results are (P<0.05).

Females and males data were analyzed independently.

results

Results

Children’s mothers not assessed with PPVT-R were

Probably unmarried

Diagnosis with anxiety and depression

Short period of breastfeeding

Children not assessed were

Weight at birth is less than assessed.

Mothers’ knowledge of pregnancy is considered unimportant

Results (continue)

Generally, after taking PPVT-R, children who were breastfed for more than six months had higher scores(103.6) than those were never breastfed(94.2).

Males and females were investigated independently and the results were that females had higher scores than males. Moreover, females and males who were breastfed more than six months had higher scores than children who never breastfed.

There was a tendency to increase in PPVT-R scores in accordance with increasing in period of breastfeeding.

Results

After taking cofounding variables into consideration, linear regression is used, such as birth weight, poverty and others which called is the adjusted model.

After using adjusted model for males and females, the results were:

Males’ and females’ PPVT-R scores decreased. However, children’s tests scores increased in accordance with increasing in period of breastfeeding.

Conclusion

The duration of breastfeeding is important. Mothers should breastfeed their children for 6 months and more due to the strong effect on children’s cognitive development.

Discussion This study is related to other studies regarding considering

confounding variables.

Other studies suggested that cognition development is related to other factors rather than breastfeeding such as maternal characteristics and environment that children live in.

Other studies suggested that breastfeeding has no relationship with children social behaviors later in life. Thus, these studies draw the conclusion that the relationships between breastfeeding and cognitive development has no connection with other factors such as social factors.

The relationship between breastfeeding and cognitive development is said to be due to the milk characteristics . In fact, breast milk have some elements that is related to the development of children cognitive abilities.

Quality criteria

Objectivity : The study had been done by a group of researches. So bias would be considered of no relevance. Also, study took into account different confounding variables that may falsely attribute the relationship between the variables of main interests.

Reliability: Reliability means that the results will be the same if the same instruments were used. In this case, I believe the results may vary based on the confounding variables that are of most concern to the researches.

Validity : Had the study measured what it was supposed to measure? In fact, the research hypothesis was if there was a relationship between breastfeeding duration on children cognition development. After the conduction of the study, it was apparent that there was significant effects of breastfeeding duration on children’s cognition.

Quality Criteria

Representative Sampling

In this study, the representative sample is 3880 children (1842 females and 2038 males) selected from from Queensland study of pregnancy (MUSP) project. It is considered represent the children population.

Replication

Any study that cannot be replicated is of no value. In this case, the study can be replicated by using different people and examining the same variables. In this case, to replicate the study, a researcher can select another group of participants and examine the same variables: confounding variables stated in the study, breastfeeding period as independent variables and children cognition.

Theoretical perspective

The theoretical perspective of this study is cognitive development theory.

This theory emphasized cognitive development according to stages and in accordance to social and biological forces

This theory applies to the study to the reasons below:

This study concerns cognitive development in children which is strongly emphasized in Piaget theory which was shown in the study hypothesis.

Take Home Message

Study one contradicted study in regard to the effectiveness of breastfeeding period on children cognition. In fact, study one stated that there is not a linear correlation between breastfeeding and cognition whereas the second indicated that there was a correlational relationship between breastfeeding period

According to the studies, Scientifically, first study is more accurate since it took into account the multiple confounding variables. However, most previous research were in agreement with study two.

Take home MessageLimitation: In order to judge the validity of research on a single research topic, investigators should not draw conclusions based on one or two studies. There must be multiple research studies that have the same results.

Confounding variables are very tricky and can sometimes be conceivable.

Future research

Replication of the two studies

Participants can be chosen from countries other than USA.

Considering other confounding variables

References Jiang, M., Foster, E., & Gibson-Davis, C. M. (2011). Breastfeeding and the

child

cognitive outcomes: A propensity score matching approach. Maternal and

Child Health Journal, 15(8), 1296-1307. doi:10.1007/s10995-010-0677-5

 

Quinn, P. J., O'Callaghan, M. M., Williams, G. M., Najman, J. M., Andersen, M. J., &

Bor, W. W. (2001). The effect of breastfeeding on child development at 5 years: A

cohort study. Journal of Paediatrics and Child Health, 37(5), 465-469.

doi:10.1046/j.1440-1754.2001.00702.x

Rubric Total Assignment = 100 pts (=23% of course grade)

10 pts -- Your research question/ appropriate selection of articles and presentation length--total presentation should be no shorter than 20 and no longer than 40 slides

45 pts -- Summary of each study; please include for each study the following.

a. Purpose of Study--what are the study's research questions? (6 pts) b. Design --First, answer this question: is this study experimental?, quasi-experimental?, or correlational? Experimental=are there randomly assigned groups that were treated differently?, Quasi-Experimental--are there groups that naturally occurred--e.g., smokers vs. non-smokers--that were treated differently by the researcher?, Correlational--a group is described and the results show differences among the group members? Second, IF the study has a developmental focus, analyze the developmental design: cross-sectional, longitudinal, or sequential. (6 pts)c. Methods--include participants, materials/instruments, data collection techniques, and data analysis techniques. After summarizing the methods, analyze what the researchers did in terms of the criteria of 1) objectivity, 2) reliability, 3) validity, 4) representative sampling, and 5) replication. (21 pts)

Rubric

c. Methods--include participants, materials/instruments, data collection techniques, and data analysis techniques. After summarizing the methods, analyze what the researchers did in terms of the criteria of 1) objectivity, 2) reliability, 3) validity, 4) representative sampling, and 5) replication. (21 pts)d. Findings--look for information indicating significant differences--connect the findings back to the research hypotheses. The findings should be contained in the Results section of the paper (6 pts)e. Conclusions--summary of authors' interpretations from Discussion section (6 pts)

Rubric 15 pts--Theoretical Perspective--what are the researchers' (probably implicit) perspectives on human development?--defend your decisions for each study with reasons (from the purpose, design, data collection and analysis, results, and interpretation); you should 1) identify (2 pts), 2) explain (5 pts), and 3) defend (8 pts) whether the perspective of each study is organismic, cognitive-developmental, cognitive-learning, behavioral, psychodynamic, contextual, or humanistic. If possible to determine the specific theory being tested by the study, further analyze the origins of the developmental approach being used. Be sure to defend your point of view.

15 pts -- Take Home Message--having read these two studies (notice this is a comparative analysis), what do you now believe? (=conclusions, 5 pts) What other questions do you have? (=future research questions, 5 pts) What can you not know for sure? (=limitations, 5 pts)