Duc 2015-pediatrics international

1. Original Article
Developmental risk factors in Vietnamese preschool-age children:
Cross-sectional survey
Nguyen Huu Chau Duc
Department of International Health and Medicine, Graduate School of Tokyo Medical and Dental University, Tokyo, Japan and
Department of Pediatrics, Hue University of Medicine and Pharmacy, Vietnam
Abstract Background: Early childhood development (ECD) strongly influences children’s basic learning, school success, economic
participation, social citizenry and health. Although some risk factors related to childhood development are documented,
further exploration is necessary considering various sociodemographic, nutritional, and psychosocial factors. This study
investigated factors affecting ECD in Vietnamese preschoolers.
Methods: We used data from the representative, cross-sectional round of the Vietnam Multiple Indicator Clusters Survey
2011. Early Childhood Development Index questionnaires were administered to mothers of all children aged 36–59 months
in the household (n = 1459). Descriptive statistics and multivariate logistic regression were used in the analysis.
Results: In Vietnam, 17.2% of children did not reach their full developmental potential within the first 5years. Children who
had been breast-fed (AOR, 2.78; 95%CI: 1.28–6.02), attended preschool (AOR, 1.75; 95%CI: 1.28–2.39), were of major
ethnicity (AOR, 2.41; 95%CI: 1.55–3.74), had a mother with secondary or higher education (AOR, 1.69; 95%CI: 1.19–2.38)
and had relatives who engaged with them in four or more activities that promote learning (AOR, 1.55; 95%CI: 1.13–2.14) were
more likely to have a normal developmental trajectory. Furthermore, children who experienced physical punishment and
stunting were 0.69-fold (95%CI: 0.51–0.95) and 0.71-fold (95%CI: 0.51–0.98) less likely to be on track for ECD, respectively.
Conclusions: The risk factors associated with delayed ECD were low level of maternal education; family ethnicity; lack of
preschool attendance; relatives who did not engage with them in learning; physical punishment; not being breast-fed; and
stunting.
Key words early childhood development, literacy–numeracy, physical capacity, social–emotion, Vietnam.
Early childhood development (ECD) is considered to be one of the
most important phases in a person’s life and a determinant of
health, wellbeing, learning and behavior across the life span.
ECD has a strong impact on one’s basic learning, school success,
economic participation, social citizenship and health later in life.
As a result, healthy ECD – in physical, social–emotional, and
language–cognitive aspects – is fundamental not only to success
and happiness during a person’s childhood, but also throughout
one’s life course.
It is estimated that >200 million children in developing coun-
tries do not reach their full potential in the first 5 years. Children
living in these developing countries are exposed to multiple risk
factors including poverty, malnutrition, poor health, and non-
stimulating home environments, which negatively affect their
physical, social–emotional, and language–cognitive development.1
Some sociodemographic and nutritional factors related to ECD
such as household wealth, maternal education, place of residence,
gender, stunting, as well as psychosocial factors such as early child-
hood education programs have been studied.2–11
Several studies
found a link between socioeconomic status and children’s cogni-
tion3
and school attainment.4
A study from Madagascar showed
that preschool-age children from the wealthiest families or whose
mothers had secondary education performed better across a wide
range of cognitive and language tests.5
Wealth quintile was related
to IQ at 8 years in Philippines,6
and cognitive scores at 9 years in
Indonesia.7
Poverty was found to have multiple adverse effects
on children. It is associated with poor maternal education, increased
maternal stress and depression8–10
and inadequate stimulation at
home.11
All these factors are detrimental to child development. Pre-
vious studies have also shown that children living in conditions of
poverty suffer from delayed growth and increased risk of growth
faltering.12,13
Other factors, however, such as ethnicity and physi-
cal punishment also need to be studied.
Moreover, despite the compelling evidence for poor child de-
velopment in low- and middle-income countries, there is a paucity
of research on this topic in Vietnam. Furthermore, the existing stud-
ies are hindered by some methodological limitations. For example,
a cross-sectional study from Vietnam found associations between
chronic malnutrition, as evidenced by stunting, and poor cognitive
function among 3055 children aged 9years,14
but that study sample
was limited to three districts of northern Vietnam. Another study
covered only one district of northern Vietnam.15
Based on these considerations and using nationally representa-
tive population-based data from Vietnam, we therefore examined
Correspondence: Nguyen Huu Chau Duc, MD, Department of Interna-
tional Health and Medicine, Graduate School of Tokyo Medical and
Dental University, Tokyo, Japan. Email: nguyenhuuchauduc@gmail.com
Received 24 September 2014; revised 9 January 2015; accepted 15
June 2015.
© 2015 Japan Pediatric Society
Pediatrics International (2016) 58, 14–21 doi: 10.1111/ped.12748

2. whether, in addition to known risk factors, other unknown risk
factors such as ethnicity and physical punishment are associated
with ECD (literacy–numeracy, physical capacity, social–emotion,
and learning) among children aged 36–59months. The present
findings may help to fine-tune suitable national strategies, ensuring
continued improvement in child development programming in
Vietnam, and in South-east Asia in general.
Methods
Data sources and sampling
We used data from the representative, cross-sectional round of the
Vietnam Multiple Cluster Survey (MICS 2011) conducted during
2010–2011. MICS 2011 was conducted by the General Statistics
Office in Vietnam and used a method designed by the United
Nations Children’s Fund (UNICEF).The surveys included three
sets of questionnaires: a household questionnaire; a questionnaire
administered only to women of reproductive age (15–49 years)
living in the household; and a questionnaire regarding children
under 5 years living in the household, administered to the women
or caregivers. The questionnaires were drafted in English and then
translated into Vietnamese, the national language of Vietnam. The
translations were reviewed by experts and volunteers, and a pilot
study was conducted as a validation exercise.
Among the women aged 15–49years who were deemed eligible
to complete the women’s questionnaires on maternal and child
health behaviors and outcomes, 11663 of 12115 completed the
questionnaire, yielding a response rate of 96.3%.
The questionnaire for children was administered to all mothers
or caregivers who cared for a child under 5years living with them.
Only information on children aged 36–59 months was used for the
analysis, with a final sample size of 1459. Detailed descriptions of
the study design and the methods used for data collection are acces-
sible online in household survey reports.16
Measurement
The 2011 MICS used a 10-item module to measure Early Child-
hood Development Index (ECDI). A validation study of the recom-
mended items was conducted in order to ensure reliability and
feasibility of the scale. Moreover, the reliability of those items
(both test–retest and inter-rater reliability) was also checked before
implementation of the module.17
Each of the 10 items was used to
determine whether children were developmentally on track in one
of the four domains: literacy–numeracy, physical capacity,
social–emotion, and learning. To measure literacy–numeracy, the
survey asked whether the child could achieve at least two of these
tasks: name at least 10 letters of the alphabet; read at least four
simple, common words; know the name and recognize the symbols
of all numbers from 1 to 10. To measure physical capacity, the
caregivers were asked whether the child was able to pick up a small
object such as a stick or a rock from the ground with two fingers;
and whether the caregivers did not indicate that the child was some-
times too sick to play. Social–emotion was measured according to
whether at least two positive responses to the following questions
were recorded: if the child gets along well with other children; if
the child does not kick, bite, or hit other children; or if the child
does not get distracted easily. In addition, learning domain was
measured according to whether the child could follow simple direc-
tions on how to do something correctly; or, when given something
to do, was able to do it independently. The ECDI is calculated as
the percentage of children who are developmentally on track in at
least three of these four domains. Detailed descriptions of the
methods are accessible online in household survey reports.16
We included several theoretically pertinent sociodemographic
factors as independent variables. Household wealth status was
determined based on a wealth score calculated by principal compo-
nent analysis of an asset and household wealth index. Each house-
hold was then weighted by the number of household members, and
the household population was divided into five groups of equal
size, from the poorest quintile to the richest quintile, based on the
wealth scores of the households in which the household members
were living. In the present study, we considered two groups of
wealth status: poorest (first quintile) versus second–fifth quintile.
There are two reasons for this grouping: (i) the first quintile
(poorest) identifies households that both have the lowest absolute
level of wealth and, by virtue of their location in the ranking of
households on wealth, are also relatively the poorest (comparing
the first quintile [poorest] to other quintiles allows us to clearly
see the effect of both poverty and ECD); and (ii) the poorest has
very limited income, especially in rural Vietnam: 20% of house-
holds belonging to the first quintile possess only 5.7% of total
income compared with the other quintiles.18
Maternal education was defined in terms of the formal education
system of Vietnam: no education (0years), primary (1–5 years),
secondary (6–9 years), and higher (≥10years). Vietnam is an ethni-
cally diverse country, with 54 different ethnic groups. People who
belong to an ethnic minority tend to be marginalized and discrimi-
nated against. This background affects their social status prospects
and opportunities and is often associated with poor mental and phys-
ical health.19
Therefore, a distinction was made between women
according to ethnicity: belonging to the majority (Kinh group), or
to a minority (non-Kinh group). Place of residence was categorized
as rural or urban. Parity was categorized as one, two, three, or more.
Psychosocial factors including early learning, support for
learning, and exposure to violence were used. Data on disciplinary
practices were collected in MICS using a modified version of the
short form of the Parent to Child Conflict Tactics Scale or
CTSPC.20
The questionnaire was addressed to the mother of one
randomly selected child 36–59 months of age in each household.
The physical or corporal punishment practices covered in the ques-
tionnaire included shaking, slapping or hitting the child on various
body parts (with or without an implement). A binary variable was
created to assess attitudes towards physical punishment based on
whether the mothers responded to the necessity of using physical
punishment to raise the child with yes versus no. Information on
a number of activities that support early learning included the
involvement of the child’s relatives in the following activities:
reading books or looking at picture books, telling stories, singing
songs, taking the child outside the home, playing with the child
and spending time with the child to help naming, counting, or draw-
ing things. Preschool attendance in an organized learning or child
education program was created as a binary variable (yes vs no).
Developmental risk factors in ECD 15
© 2015 Japan Pediatric Society

3. We also included the child malnutrition variables of stunting
and wasting in the analysis. Stunting is defined using height for
age, while wasting is determined using weight for height. Children
whose height for age or weight for height are >2SD below the
median of the reference population are classified as moderately or
severely stunted or wasted.16
Statistical analysis
Descriptive statistics were used to identify socioeconomic and
demographic factors in ECD. Fully adjusted models were created
to analyze ECDI as well as its domain. All covariates were entered
simultaneously in multiple regression models. Multicolinearity in
the logistic regression analysis was investigated in this study by
examining the variance of inflation factors, which was <2.0.
Adjusted OR (AOR) was estimated to assess the strength of the
associations, and 95%CI was used for significance testing. Stata
MP version 11 (Stata, College Station, TX, USA) was used for
all analyses.
Ethics
The present study was based on secondary data analysis of existing,
publicly available survey data from which all personally identifi-
able information had been removed. Before participating in the
survey, all the participants were asked to provide informed consent
after being read a document emphasizing the voluntary nature of
this project, outlining the potential risks, and explaining that the
information gathered would be used to assess health-care needs
and to plan health services. Each participant was allowed to
withdraw from the study at any time. The confidentiality of the
entire data set was maintained at all stages of data collection.
Results
Descriptive statistics
Table 1 shows that most of children aged 36–59 months were
living in rural areas (73.5%) and belonged to the major ethnicity
(87.4%). Seventy seven percent of children were living in
2nd–5th quintile households and 73.3% of children had a mother with
secondary or higher education. The female:male ratio was 1:1.01.
Table 2 shows that 71.9% of children aged 36–59 months were
attending early childhood education programs in Vietnam. Approx-
imately three-fourths (76.8%) of children had adults (relatives) who
engaged with them in more than four activities that promote learn-
ing and school readiness during the 3days preceding the survey.
Only 16.3% of mothers believed that it was necessary to use phys-
ical punishment to raise/educate children, but 61.7% of children ex-
perienced at least one physical punishment. Spanking with bare
hand (52.1%) was the most common punishment used by mothers.
Approximately 19.1% of mothers reported that they had hit their
children with a hard object at least once on the bottom or elsewhere;
and 17.4% reported hitting them on the hand, arm or leg. Children
also experienced severe discipline such as hitting on face, head or
ears (2.8%), and beating up with an implement (0.3%; Table 2).
Table 3 lists ECDI for children aged 36–59 months in Vietnam.
The percentage of children who were developmentally on track
was 82.8%. Of note, 97.7% of children were on track in the
physical domain while only 24.1% of children were on track in the
literacy–numeracy domain. The percentage of children who were
developmentally on track for the learning and social–emotional do-
mains were 91.3% and 88.6%, respectively. Regarding the ECDI
subscales, the highest percentage of children (36.8%) knew the
names and recognized the symbols of all numbers from 1 to 10 in
the literacy–numeracy domain. In the physical and social–
emotional domains, the highest percentage was observed for the
components picking up a small object with two fingers (91.6%)
and getting along well with other children (97%). Learning domain
was measured according to whether the child could follow simple
directions on how to do something correctly (88.4%), or, when
given something to do, was able to do it independently (77.2%).
Given that some children had a positive response in two compo-
nents, one component, or none in this domain, when positive re-
sponse in at least one component was used, 91.3% of children
were developmentally on track in the learning domain.
Multivariate analysis
Table 4 lists the association of ECD with sociodemographic and psy-
chosocial factors. Children whose mothers had secondary or higher
education (high education) were 1.69-fold (95%CI: 1.19–2.38) more
likely to achieve their full potential compared with the children of
Table 1 Characteristics of children aged 36–59 months, Vietnam,
2011 (n = 1459)
Characteristic n %
Economic status
Poorest 336 23.0
Poorer 272 18.6
Middle 274 18.7
Richer 315 21.6
Richest 263 18.0
First quintile 336 23.0
2nd–5th quintiles 1123 77.0
Maternal education
No schooling 97 6.7
Primary 292 20.0
Secondary 606 41.5
Higher 464 31.8
Under secondary (low education) 389 26.7
Secondary or higher (high education) 1070 73.3
Place of residence
Urban 387 26.5
Rural 1072 73.5
Ethnicity
Minority (Non-Kinh) 184 12.6
Majority (Kinh) 1275 87.4
Age
36-47 months 764 52.4
48-59 months 695 47.6
Gender
Female 733 50.3
Male 726 49.7
Breast-feeding status
Never 35 2.4
Formerly breast-fed 1424 97.6
Nutritional status
Stunting 317 21.8
Wasting 54 3.7
16 NHC Duc
© 2015 Japan Pediatric Society

4. mothers with below secondary education. Children with high educa-
tion mothers were also 1.83-fold (95%CI: 1.15–2.91) and 2.9-fold
(95%CI: 1.28–6.58) more likely to be developmentally on track in
the learning and physical domains, respectively.
Children residing in urban areas were 1.6-fold (95%CI:
1.21–2.12) and 2.06-fold (95%CI: 1.12–3.76) more likely to
be in the normal range in literacy–numeracy and learning,
respectively, compared with rural children. Children in the
major ethnic group (Kinh) were 2.41-fold (95%CI: 1.55–3.74)
more likely to be on track according to ECDI. Kinh children
were 2.45-fold (95%CI: 1.42–4.25) and 2.66-fold (95%CI:
1.57–4.52) more likely to have better outcomes in the social–
emotion and learning domains, respectively. Furthermore, girls
were 0.42-fold (95%CI: 0.20–0.86) less likely to be develop-
mentally on track in the physical domain compared with boys.
With regard to psychosocial factors, children attending in an
early childhood education program were 1.75-fold (95%CI:
1.28–2.39), 2.89-fold (95%CI: 2.02–4.15), and 2.39–fold
(95%CI: 1.58-3.62) more likely to reach their potential in over-
all development, as well as in the literacy–numeracy, and learn-
ing domains, respectively. Furthermore, children who had
relatives who engaged with them in more than four activities
that promote learning and school readiness were 1.55-fold
(95%CI: 1.13–2.14), 1.89-fold (95%CI: 1.31–2.75), and 2.01-fold
Table 3 ECDI for children aged 36–59 months in Vietnam, 2011 (n = 1459)
Early childhood development index (ECDI) n %
On track†
1208 82.8
Off track 250 17.2
Developmentally on track in ECDI domains
Literacy–numeracy‡
351 24.1
Physical§
1426 97.7
Social–emotional¶
1292 88.6
Learning††
1331 91.3
ECDI domain components
Literacy–numeracy domain
Name at least 10 letters of the alphabet 350 24.0
Read at least four simple, common words 310 21.2
Know the name and recognize the symbols of all numbers from 1 to 10 537 36.8
Physical domain
Pick up a small object with two fingers 1336 91.6
Did not indicate that the child was sometimes too sick to play 1123 77.0
Social–emotional domain
Get along well with other children 1415 97.0
Not kick, bite, or hit other children 1148 78.7
Not get distracted easily 978 67.0
Learning domain
Follow simple directions on how to do something correctly 1290 88.4
Able to do something independently 1126 77.2
†
At least three ECDI domains fulfilled; ‡
at least two literacy–numeracy components achieved; §
both of two physical components achieved;
¶
at least two social–emotion components achieved; ††
at least one learning component achieved. ECDI, early childhood development index.
Table 2 Psychosocial factors for children aged 36–59 months in Vietnam, 2011 (n = 1459)
Indicators n %
Attendance at an early childhood education program 1049 71.9
Adult engaged with them in stimulating activities in the past 3 days
Read books to or looked at picture books with the child 670 46.0
Told stories to the child 979 67.1
Sang songs to the child or with the child, including lullabies 1202 82.4
Took the child outside the home, compound, yard or enclosure 1253 85.9
Played with the child 1318 90.3
Named, counted, or drew things to or with the child 1168 80.1
Engaged in four or more activities with the child 1120 76.8
Physical punishment
Shaking 110 7.6
Hitting on the bottom with bare hand 760 52.1
Hitting child on the bottom or elsewhere on the body with hard object 278 19.1
Hitting on the hand, arm, or leg 254 17.4
Hitting on the face, head or ears 41 2.8
Beating up with an implement (repeated hitting with maximum force) 3 0.3
Experienced at least 1 physical punishment 900 61.7
Believe physical punishment is necessary to raise/educate a child 238 16.3
Developmental risk factors in ECD 17
© 2015 Japan Pediatric Society

5. Table4FactorsassociatedwithECDIamongchildrenaged36–59monthsinVietnam,2011(n=1459)
Independent
variables
EarlychilddevelopmentindexSocial–emotionaldomainLiteracy–numeracydomainLearningdomainPhysicaldomain
AOR(95%CI)AOR(95%CI)AOR(95%CI)AOR(95%CI)AOR(95%CI)
Sociodemographicfactors
Householdwealth
Poorestquintile—————
2nd–5thquintiles0.69(0.46–1.04)0.49*(0.29–0.85)0.95(0.63–1.42)1.20(0.72–2.01)0.66(0.25–1.74)
Maternaleducation
Loweducation—————
Higheducation1.69**(1.19–2.38)1.15(0.76–1.75)1.37(0.95–1.98)1.83*(1.15–2.91)2.90*(1.28–6.58)
Placeofresidence
Rural—————
Urban1.39(0.96–2.02)0.76(0.52–1.12)1.60**(1.21–2.12)2.06*(1.12–3.76)0.85(0.35–2.07)
Ethnicity
Minority—————
Majority2.41***(1.55–3.74)2.45**(1.42–4.25)1.05(0.63–1.75)2.66***(1.57–4.52)1.59(0.59–4.27)
Gender
Male—————
Female0.82(0.61–1.09)1.31(0.94–1.83)1.03(0.80–1.33)0.69(0.47–1.03)0.42*(0.20–0.86)
Parity
1or2children—————
3ormore0.85(0.62–1.16)0.81(0.57–1.17)0.96(0.72–1.28)0.95(0.62–1.46)0.93(0.44–1.97)
Nutritionalstatus
Breast-feeding
Never—————
Formerly2.78**(1.28–6.02)2.22(0.97–5.08)1.95(0.77–4.93)7.66***(3.23–18.17)4.34*(1.04–18.14)
Wasting
No—————
Yes0.89(0.43–1.81)0.73(0.33–1.62)0.83(0.40–1.69)1.09(0.39–2.99)1.32(0.21–8.38)
Stunting
No—————
Yes0.71*(0.51–0.98)1.00(0.66–1.52)0.49***(0.34–0.72)0.54**(0.36–0.82)0.27***(0.13–0.55)
Psychosocialfactors
Earlychildhoodeducationprogram
Non-attendance—————
Attendance1.75***(1.28–2.39)1.35(0.93–1.96)2.89***(2.02–4.15)2.39***(1.58–3.62)1.39(0.67–2.89)
Adultengagedwiththeminlearning
No—————
≥4activities1.55**(1.13–2.14)1.89**(1.31–2.75)2.01***(1.39–2.91)0.92(0.59–1.44)0.98(0.45–2.13)
Motherbelievesinphysicalpunishment
No—————
Yes1.11(0.76–1.63)0.75(0.49–1.14)0.48**(0.32–0.73)2.06*(1.13–3.76)1.02(0.41–2.49)
Physicalpunishment
No—————
Yes0.69*(0.51–0.95)0.62**(0.43–0.88)1.01(0.75–1.36)0.77(0.51–1.19)0.91(0.43–1.96)
*P<0.05,**P<0.01,***P<0.001,Allcovariatesadjustedinthemodel.ECDI,earlychildhooddevelopmentindex.
18 NHC Duc
© 2015 Japan Pediatric Society

6. (95%CI: 1.39–-2.91) more likely to have better development in
terms of ECDI, social–emotional, and literacy–numeracy, respec-
tively. In contrast, children who experienced physical punishment
were 0.69-fold (95%CI: 0.51–0.95) and 0.62-fold (95%CI:
0.43–0.88) less likely to be developmentally on track in ECDI
and social–emotional aspects.
Regarding nutritional status, children who had been breast-fed
were 2.78-fold (95%CI: 1.28–6.02) more likely to have ECDI in
the normal range. Breast-feeding was also associated with 7.66-fold
(95%CI: 3.23–18.17) and 4.34-fold (95%CI: 1.04–18.14) improve-
ment in learning and physical development, respectively. Children
with stunting were 0.71-fold (95%CI: 0.51–0.98) less likely to
have ECDI in the normal range. Stunted children also were 0.49-
fold (95%CI: 0.34–0.72), 0.54-fold (95%CI: 0.36–0.82), and
0.27-fold (95%CI: 0.13–0.55) less likely to be developmentally
on track in the literacy–numeracy, learning, and physical domains.
Discussion
This is the first study to examine the factors associated with ECD in
Vietnam using a large, nationally representative survey. Given the
large nationally representative survey and adequate sample size,
this paper provides an unbiased analysis, and has uncovered two
major findings. First, 17.2% of Vietnamese children did not reach
their full developmental potential within the first 5 years. Second,
having a well-educated mother, having been breast-fed, attending
an early childhood education program or having relatives
engaged in their learning are positive factors associated with good
developmental progress in children aged 36–59 months. In con-
trast, stunting was found to be a negative factor for child develop-
ment. These factors were similar to those reported in other
regions.14,21–39
In addition, the present study identified that ethnic-
ity and physical punishment play a role in child development.
Despite assistance from the government of Vietnam, the minor-
ity ethnic groups (non-Kinh) still lag behind in terms of living stan-
dards. Households of these groups in Vietnam are not only poorer
but also more vulnerable to various shocks than those in the major
ethnic group. Children of ethnic minorities have less access to
education, higher dropout rates, and higher rates of
stunting,19,40
which may partly explain the lower prevalence
of on-track development. We also found that children belong-
ing to the minority ethnic groups had mothers with lower
education and had higher rates of stunting. Although some
small-scale studies were conducted in Vietnam to identify the
risk factors of childhood development, they ignored ethnicity.
In future studies, ethnicity should be included as an important
risk factor of child development in Vietnam.
The underpinning association between childhood exposure to
physical punishment and increased risk of social–emotional and
ECDI problems may be explained by the fact that physical punish-
ment is associated with a range of mental health problems in
children. These problems are: depression, unhappiness, anxiety,
feelings of hopelessness because of increasing cortisol or of the
chemical disruption of the brain’s mechanism for regulating
stress.41–46
Therefore, they may experience maladaptive wear and
tear on their physiological response systems, which are then
activated in response to mental health problems. As a result, children
are less capable of habituating to new events, or regulating their own
emotional reactions in adaptive ways. In addition, physical punish-
ment during childhood may reflect customs and habits that give pri-
ority to parental rights in Vietnamese culture. It is normally accepted
that parents and other members of the family should discipline their
children if they make mistakes or refuse adults’ orders.47
Further-
more, provision against violence and abuse in the Law on the
Protection, Care and Education of Children 1991 (amended 2004),
the Law on Marriage and Family (art.26) and the Law on Domestic
Violence Prevention and Control 2007 were not interpreted as
prohibiting all physical punishment in childrearing.48–50
These
factors might explain the widely accepted practice of physical
punishment in child rearing. This evidence indicates that physical
punishment is an important factor for clinicians as well as policy
makers, in that it has a negative impact on early child development
in Vietnam, and requires effective strategy implementation to pre-
vent and eliminate domestic violence and abuse.
Early learning facilitating cognitive development includes pre-
school education attendance and adult engagement in stimulating
activities that promote early learning and school readiness. Lack
of early learning opportunities and appropriate caregiver–child
interactions decreased the developmental potential of children.
Early learning had a beneficial effect of cognitive stimulation in
child task orientation, social behaviors, self-confidence…21–24
Also, children who attended an early childhood education program
and who had adult household members who engaged with them in
more than four activities that promote learning and school readi-
ness were more likely to reach their potential in overall develop-
ment, as well as in the social–emotional, literacy–numeracy, and
learning domains. This strongly supports the importance of early
cognitive stimulation during ECD.
The present study also found that although 82.8% of children
reached their full developmental potential, the rate of children
who were in the normal range for literacy–numeracy was low
(24.1%). Literacy and numeracy are core life skills and the acquisi-
tion of these abilities has a profound impact on individuals, fami-
lies, communities and the nation.51
Strong evidence indicates that
early learning stimulation from the family such as book reading
or story telling, has a significant positive impact on child education,
especially literacy and numeracy.25,26
Although home-based edu-
cation plays the most important role in supporting the holistic de-
velopment of children in the early years, the knowledge and skills
of parents and caregivers of early childhood care and education
are very limited.52
Additionally, learning material for children at
home also remains limited: only 19.6% of children aged <5years
lived in households where at least three children’s books were
present, and 49.3% had two or more toys to play with.16
We also
found that stimulating activities such as book reading or story
telling were limited at the household level. Furthermore, on
multivariate analysis, children who attended an early childhood ed-
ucation program and had an adult household member who engaged
with them in more than four activities that promote learning and
school readiness were twofold more likely to achieve the core
educational skills compared with their counterparts. These findings
from a national representative sample are in line with previous
Developmental risk factors in ECD 19
© 2015 Japan Pediatric Society

7. studies,27,28
and indicate that early learning-stimulating activities
are important in ECD assessment. This also confirms that develop-
ment of good literacy and numeracy skills during the early years is
critical to ECD, and essential in Vietnamese society.
Regarding nutritional status, previous studies showed that mal-
nutrition, especially stunting, had a negative influence on cognitive
development,29–33
and that breast-feeding was associated with
improved developmental outcomes.34–37
We found that stunted
children not only experience more difficulty in reaching full phys-
ical development but also have less chances to reach full potential
in overall development, in literacy–numeracy and in learning.
Formerly breast-fed children were more likely to be on track in
overall development, learning and physical domains compared
with non-breast-fed children. These findings again underline the
importance of nutrition in cognitive development.
As expected, children with educated mothers had better scores
in overall development, learning and physical domains. These
findings are in line with previous studies and indicate that maternal
education background affects child cognitive development by
means of environmental organization, parental expectations and
practices, provision of materials for cognitive stimulation, and
variety in daily stimulation for the child.5,38,39
Strengths and limitations
The main strength of the present study is that the data came from
the large and nationally representative survey performed in 2011. A
relevant subset was extracted consisting of women aged 15–49 years
who had a live birth in the 2years preceding the survey, providing a
large sample size. The survey interviewers were trained to respond
to questions about the selected topics, and the fieldwork was
monitored through visits by representatives from the Ministry of
Health and UNICEF.
Some limitations should be considered when interpreting the
present findings. First, the current analysis was cross-sectional in
nature and involved the reporting of past behaviors; therefore, a
possible recall bias existed. The recall period, however, was limited
to 2years to minimize recall bias. Second, the study was based on
self-reported outcome, which might have resulted in a response
bias. MICS, however, stated that the respondents were informed
of the importance of providing accurate responses and were also
assured of the confidentiality of their responses. Third, the present
study can be criticized for the use of an indirect measure of house-
hold wealth, but, given that reliable income and expenditure data
are difficult to obtain in developing countries, such as Vietnam,
an asset-based index is generally considered a good proxy for
household wealth status. Finally, because the selection of variables
was constrained by the pre-existing MICS data, we were unable to
include additional, potentially important variables. Although
limitations in the available data can be identified, we believe that
the present study provides important information on areas where
investment and intervention are needed, to enable the children of
Vietnam to achieve their full developmental potential.
Conclusions
Developmental risk factors that affect Vietnamese preschool-aged
children were low maternal education level; lack of attendance at
an early childhood education program; not being breast-fed;
relatives who did not engage with them in learning; and stunting.
Ethnicity and physical punishment should also be included as
contributing factors in childhood development in the context of
Vietnam. The present findings may be relevant to other settings
and also of interest to clinicians when assessing children with
different problems related to full developmental potential.
Acknowledgments
The author would like to thank all the teams that conducted the
Vietnam Multiple Indicator Cluster Survey. The author extends
his deep appreciation to his direct supervisor, Professor Keiko
Nakamura, Head, Department of International Health and Medi-
cine, Division of Public Health, Graduate School of Tokyo Medical
and Dental University, Tokyo, Japan, for her guidance and
thoughtful insights. The author is also indebted to Dr Masashi
Kizuki, Dr Kaoruko Seino, Dr Pham Nguyen Quy, Mr Hoang
Huy Dung and Ms Tran Ngoc The Tu for their advice and support.
The author declares no conflicts of interest.
References
1 Grantham-McGregor S, Cheung YB, Cueto S et al. Developmental
potential in the first 5 years for children in developing countries.
Lancet 2007; 369: 60–70.
2 Houweling TA, Kunst AE. Socio-economic inequalities in child-
hood mortality in low- and middle-income countries: A review of
the international evidence. Br. Med. Bull. 2010; 93: 7–26.
3 Sigman M, McDonald MA, Neumann C, Bwibo N. Prediction of
cognitive competence in Kenyan children from toddler nutrition,
family characteristics and abilities. J. Child Psychol. Psychiatry
1991; 32: 307–20.
4 Stein AD, Behrman JR, DiGirolamo A et al. Schooling, educa-
tional achievement and cognitive functioning among young
Guatemalan adults. Food Nutr. Bull. 2005; 26: S46–54.
5 Fernald LC, Weber A, Galasso E et al. Socioeconomic gradients
and child development in a very low income population: Evidence
from Madagascar. Dev. Sci. 2011; 14: 832–47.
6 Mendez MA, Adair LS. Severity and timing of stunting in the first
two years of life affect performance on cognitive test in late child-
hood. J. Nutr. 1999; 129: 1555–62.
7 Cheung YB. Growth and cognitive function of Indonesian children:
Zero-inflated proportion models. Stat. Med. 2006; 25: 3011–22.
8 Bradley R, Corwyn R. Socioeconomic status and child develop-
ment. Annu. Rev. Psychol. 2002; 53: 371–99.
9 Hamadani JD, Grantham-McGregor SM. Report of the family care
indicators project: Validating the family psychosocial indicators in
rural Bangladesh. Report to UNICEF Early Child Development
Desk. UNICEF, Dahka, 2004.
10 Baker-Henningham H, Powell C, Walker S et al. Mothers of under-
nourished Jamaican children have poorer psychosocial functioning
and this is associated with stimulation provided in the home. Eur. J.
Clin. Nutr. 2003; 57: 786–92.
11 Schady N, Paxson C. Cognitive Development Among Young Chil-
dren in Ecuador: The Roles of Health, Wealth and Parenting.
World Bank Policy Research Working Paper 3605, May, 2005.
World Bank, Washington DC, 2005.
12 Martorell R, Schroeder DG, Rivera JA et al. Patterns of linear
growth in rural Guatemalan adolescents and children. J. Nutr.
1995; 125 (4 Suppl): 1060S–67.
13 Neumann CG, Harrison GG. Onset and evolution of stunting in
infants and children. Examples from the human nutrition
20 NHC Duc
© 2015 Japan Pediatric Society

8. collaborative research support program. Kenya and Egypt studies.
Eur. J. Clin. Nutr 1994; 48 (Suppl 1): S90–102.
14 Hall A, Khanh LN, Son TH et al. An association between chronic
under-nutrition and educational test scores in Vietnamese children.
Eur. J. Clin. Nutr. 2001; 55: 801–4.
15 Watanabe K, Flores R, Fujiwara J et al. Early childhood develop-
ment interventions and cognitive development of young children
in rural Vietnam. J. Nutr. 2005; 135: 1918–25.
16 Ministry of Health, Government of Vietnam. Vietnam Multiple
Indicator Cluster Survey 2011, Final Report. Ministry of Health,
Government of Vietnam, Hanoi, 2011.
17 UNICEF. The formative years: UNICEF’s work on measuring
early childhood development. [Cited 26 November 2014.]
Available from URL: http://www.unicef.org/earlychildhood/files/
Brochure_-_The_Formative_Years.pdf
18 Vu TA. Regional Poverty Disparity in Vietnam. [Cited 18
December 2014.] Available from URL: http://www.pep-net.org/
sites/pep-net.org/files/typo3doc/pdf/files_events/anh_pap.pdf
19 Dang H-A. Vietnam: A widening poverty Gap for ethnic minori-
ties. In: Hall G, Patrinos H (eds). Indigenous Peoples, Poverty
and Development. Cambridge University Press, 2010; 304–343.
20 Straus MA, Hamby SL, Finkelhor D et al. Identification of child
maltreatment with the parent-child conflict tactics scales: Develop-
ment and psychometric data for a national sample of American
parents. Child Abuse Negl. 1998; 22: 249–70.
21 Walker SP, Wachs TD, Gradner JM et al. Child development: Risk
factors for adverse outcomes in developing countries. Lancet 2007;
369: 145–57.
22 Magwaza A, Edwards S. An evaluation of an integrated parent
effectiveness training and children’s enrichment programme for
disadvantaged families. S. Afr. J. Psychol. 1991; 21: 21–5.
23 Barbarin OA, Richter L, deWet T. Exposure to violence, coping
resources, and psychological adjustment of South African children.
Am. J. Orthopsychiatry 2001; 71: 16–25.
24 Kagitcibasi C, Sunar D, Bekman S. Long-term effects of early
intervention: Turkish low-income mothers and children. J. Appl.
Dev. Psychol. 2001; 22: 333–61.
25 Smith KE, Landry SH, Swamk PR. The role of early maternal
responsiveness in supporting school-aged cognitive development
for children who vary in birth status. Pediatrics 2006; 117: 1608–17.
26 Duursma E, Pan B, Raikes H. Predictors and outcomes of low-
incomes fathers’ reading with their toddlers. Early Child Res. Q.
2008; 23: 351–65.
27 Fleer M, Raban B. Literacy and Numeracy that Counts From Birth
to Five Years: A Review of the Literature. DEST Early Childhood
Learning Resources, Melbourne, 2005.
28 Wise S, Ungerer J, Sanson A. Childcare policy to promote child
wellbeing. Aust. Econ. Rev. 2002; 35: 180–87.
29 Skinner R. The crucial catch-up: Why reading recovery works
wonders. Shine 2010; 6: 14–15.
30 Rosales JF, Reznick JS, Zeisel SH. Understanding the role of nutri-
tion in the brain and behavioral development of toddlers and
preschool children: Identifying and overcoming methodological
barriers. Nutr. Neurosci. 2009; 12: 190–202.
31 Georgieff MK. Nutrition and the developing brain: Nutrient prior-
ities and measurement. Am. J. Clin. Nutr. 2007; 85: 614S–20.
32 Bhutta ZA. Micronutrient needs of malnourished children. Curr.
Opin. Clin. Nutr. Metab. Care 2008; 11: 309–14.
33 Stewart CP, Iannotti L, Dewey KG et al. Contextualising comple-
mentary feeding in a broader framework for stunting prevention.
Matern. Child Nutr. 2013; 9 (Suppl 2): 27–45.
34 Walker SP, Chang SM, Powell CA et al. Early childhood stunting
is associated with poor psychological functioning in late adoles-
cence and effects are reduced by psychosocial stimulation.
J. Nutr. 2007; 137 (11): 2462–9.
35 Drane DL, Logemann JA. A critical evaluation of the evidence
on the association between type of infant feeding and cogni-
tive development. Paediatr. Perinat. Epidemiol. 2000; 14:
349–56.
36 Sacker A, Quigley MA, Kelly Y. Breastfeeding and developmental
delay: Findings from the millennium cohort study. Pediatrics
2006; 118: 682–9.
37 Oddy WH, Kendall GE, Li J et al. The long-term effects of
breastfeeding on child and adolescent mental health: A preg-
nancy cohort study followed for 14 years. J. Pediatr. 2010;
156: 568–74.
38 Oddy WH, Robinson M, Kendall GE et al. Breastfeeding and early
child development: A prospective cohort study. Acta Paediatr.
2011; 100: 992–9.
39 Curtin M, Madden J, Staines A et al. Determinants of vulnerability
in early childhood development in Ireland: A cross-sectional
survey. BMJ Open 2013; 3: e002387.
40 Santos LM, Santos DN, Sousa Bastos AC, Assis AMO, Silva
Prado M, Barreto ML. Determinants of early cognitive develop-
ment: Hierarchical analysis of a longitudinal study. Cad. Saude
Publica 2008; 24: 427–37.
41 United Nation. Maternal and Child Nutrition in Vietnam. [Cited 20
September 2014.] Available from URL: http://www.un.org.vn/en/
feature-articles-press-centre-submenu-252/339-maternal-and-
child-nutrition-in-viet-nam.html
42 Afifi TO, Brownridge DA, Cox BJ et al. Physical punishment,
childhood abuse and psychiatric disorders. Child Abuse Negl.
2006; 30: 1093–103.
43 Turner HA, Muller PA. Long-term effects of child corporal punish-
ment on depressive symptoms in young adults: Potential
moderators and mediators. J. Fam. Issues 2004; 25: 761–82.
44 Javo C, Rønning JA, Heyerdahl S et al. Parenting correlates of
child behavior problems in a multiethnic community sample of pre-
school children in northern Norway. Eur. Child Adolesc.
Psychiatry 2004; 13: 8–18.
45 Rodriguez CM. Parental discipline and abuse potential effects on
child depression, anxiety, and attributions. J. Marriage Fam.
2003; 65: 809–17.
46 Bugental DB, Martorell GA, Barraza V. The hormonal costs of
subtle forms of infant maltreatment. Horm. Behav. 2003; 43:
237–44.
47 McGowan PO, Sasaki A, D’Alessio AC et al. Epigenetic regula-
tion of the glucocorticoid receptor in human brain associates with
childhood abuse. Nat. Neurosci. 2009; 12: 342–8.
48 Trang NHM, Duc NHC. Violent disciplinary practices towards
children among caregivers in Vietnam: A cross-sectional survey.
Eur. J. Soc. Sci. 2014; 43: 305–13.
49 National Assembly. Law No. 22/2000/QH10 on Marriage and the
Family. Vietnam Government, Hanoi, 2000.
50 National Assembly. Law No. 25/2004/QH11 on Child Protection,
Care and Education. Vietnam Government, Hanoi, 2004.
51 National Assembly. Law No. 02/2007/QH12 on Domestic Vio-
lence Prevention and Control. Vietnam Government, Hanoi, 2007.
52 Hopkins L, Green J, Strong G. Literacy and numeracy in the early
years. [Cited 20 September 2014.] Available from URL: https://
www.eduweb.vic.gov.au/edulibrary/public/teachlearn/student/
shinespotlightlitnum.pdf
Developmental risk factors in ECD 21
© 2015 Japan Pediatric Society