Background
Since the mid-1980s when China started to implement the reform and
opening-up policy, a growing number of people have migrated from rural to urban
areas in search of better jobs and living conditions. In recent years, an increasing
number of migrant workers have made the choice to raise their children in cities,
creating a new generation of migrant children.
In China, migrant children are defined as “children under 18 who have
left their original residence and migrated to a big city for at least 6 months”
[
1]. According to the most recent
statistics, the number of migrant children in China aged between 0 and 17 years is
about 35.80 million [
2], and this number
continues to grow [
3]. Because of the
Hukou, China’s system of household
registration, most migrant children are unable to enroll in public schools or
utilize the same social welfare provided to urban children. Unregistered schools
specifically set up for migrant children, usually called migrant-exclusive schools,
are typically small and often lack qualified teachers, standard teaching materials
and adequate sanitation facilities [
4].
A minority of migrant children can attend public schools due to regional policies,
for example, if their parents migrated to a city because of a regional
labor-importing policy. However, these migrant children may be socially excluded in
their classrooms, treated unjustly by their teachers and discriminated against by
the parents of their urban classmates [
5]. As such, migrant children experience inequitable health
conditions, both physically and mentally, in the process of adapting to a new
environment, making them extremely vulnerable.
Because of these precarious circumstances, there is great concern
regarding the health condition of migrant children, but only limited data at the
population-level have been collected regarding the mental health status of migrant
children using standardized tools in China. Although the strengths and difficulties
questionnaire (SDQ) is a standardized measure of mental health in children and
adolescents, with established reliability and validity [
6,
7], studies of the mental health status of migrant children using SDQ
in China are rarely conducted. Existing studies on the subject reported mixed
results. One study conducted in Guangdong found that migrant children scored
significantly higher in every SDQ outcome compared to normative scores in China
[
8]. Another study conducted in
Hubei found that migrant children only reported significantly higher scores in
emotional symptoms, conduct problems, hyperactivity and peer problems [
9] when compared to urban children. Meanwhile,
when compared to rural left-behind children who were still living in rural areas,
migrant children reported significantly lower scores in emotional symptoms and total
difficulties [
10].
Despite these studies demonstrating the detrimental effect of migrant
status on children’s mental health, gaps remain in the existing literature; these
studies had small sample sizes, and did not include an appropriate comparison group
to verify the impact of migrant status on mental health.
Another concern regarding migrant children and adolescents’ health
conditions is self-injurious thoughts and behaviors (SITBs), which is a serious
public health concern worldwide [
11].
In children and adolescents, two particular types of SITBs are notable: suicidal
ideation, referring to thoughts of ending one’s own life, and non-suicidal
self-injury (NSSI), defined as the direct and deliberate destruction of one’s body
tissue without the intent to die [
12].
Previous international studies have already confirmed migrant status as a risk
factor for suicidal ideation [
13] and
self-injurious behaviors [
14]. In
China, it is estimated that between 14.01 and 26.03% of children and adolescents
report suicidal ideation [
15,
16]; however, studies investigating
this phenomenon seldom investigate the impact of migrant status on these behaviors
in children and adolescents [
17]. Only
one study [
18], conducted in Shanghai,
examined the prevalence of suicidal ideation in migrant adolescents, and found the
rate to be 36.80%, without a comparison to their urban counterparts.
The present study aims to investigate the mental health status of
migrant children living in eastern coastal China in comparison to their urban
counterparts, and SITBs among this sample. Based on the aforementioned review of the
literature, two major hypotheses were developed: firstly, compared to urban
children, migrant children would score significantly higher in all SDQ outcomes and
secondly, migrant children would report significantly more SITBs.
Methods
Sample
A cross-sectional survey was conducted in a migrant receiving urban
city, the Yinzhou district of Ningbo, Zhejiang Province, between May and June
2013. The region has an estimated population of 136 million, of whom 46.60% are
migrants. There are two kinds of schools available for migrant children:
migrant-exclusive schools, utilized by the majority of migrant children; and
public schools, utilized by migrant children whose parents are relatively
socio-economically advantaged. As roughly 30% of migrant children in this area
attend public schools, 5 migrants’ schools and 8 public schools were randomly
selected from the school roster of the District Education Bureau to ensure the
comparability of sample size between the two groups.
In each school, all selected students were between grades 5 and 9.
Across the 13 schools, 4217 students (1858 migrant children and 2359 urban
children) out of 4409 eligible enrolled students completed the questionnaire,
representing a response rate of 95.65%.
Procedure
Study information was sent to the head of each school and the
District Education Bureau by mail, and approvals from both parties were
obtained. Information packs (an information letter and a consent form) were
distributed to parents by school staff to gain verifiable parental consent. The
study was performed during lunch breaks and course recesses, during which
students with parental consent were assessed collectively by two well-trained
investigators. Before filling out the questionnaire, students’ verbal agreement
to participate was obtained after a simplified study introduction given by the
investigators. The questionnaire was strictly self-administrated by students
under investigators’ uniform instruction, and teachers were off-site to ensure
anonymity.
The study was approved by the Ethics Committee of Zhejiang
University (Ref no. ZGL201412-2).
Measures
Socio-demographics
Socio-demographic characteristics included: age, gender,
migrant status, family economic status, parents’ education level and
parents’ marital status. Family economic status was measured by possession
of a number of household items, such as an air conditioner, refrigerator,
washing machine, computer and private car [
19,
20].
This variable was then coded as low- (zero to two item), moderate- (three to
four items), and high-income (five items). Parents’ education level referred
to the highest education level of one parent.
The strengths and difficulties questionnaire
Child psycho-social wellbeing was measured with the
self-reported version of the strengths and difficulties questionnaire (SDQ),
which has been validated in China [
21]. The SDQ consists of five subscales: emotional
symptoms, conduct problems, hyperactivity, peer problems and prosocial
behavior; each subscale contains five items in the form of statements
requiring a response via a three-point Likert response scale: 1 (not true);
2 (somewhat true); or 3 (certainly true) [
6]. The Cronbach’s alpha for the emotional symptoms in
this study was 0.76; 0.72 for the conduct problems; 0.77 for the
hyperactivity; 0.67 for the peer problems; and 0.79 for the prosocial
behavior. Emotional symptoms and peer problems were combined to form a
single “internalizing” subscale, conduct problems and hyperactivity were
combined to form a single “externalizing” subscale, and the third subscale,
“prosocial behavior,” remained unchanged. The total difficulties score was
calculated by adding the scores of the internalizing and externalizing
subscales. Higher scores on the total difficulties, internalizing and
externalizing subscales represent higher levels of psychological problems;
while higher scores on the prosocial behavior subscale represent lower
levels of psychological problems.
Self-injurious thoughts and behaviors (SITBs)
SITBs, including non-suicidal self-injury, suicidal thoughts,
suicide attempts and death by suicide, are widely used to obtain information
regarding adolescent suicidality [
22]. In this study, the SITBs we assessed were suicidal
ideation and non-suicidal self-injury. These two items were assessed with
the following questions: “Did you have suicidal thoughts during the past
2 weeks?” and “Did you hurt yourself deliberately during the past year?” The
following statements were identified as a “yes” answer for suicidal
ideation: “During the last 2 weeks, I had thoughts of killing myself” and
“During the last 2 weeks, I had thoughts of killing myself but I wouldn’t
carry them out”. The following statements were identified as a “yes” answer
for self-injurious behaviors: “During the past year, I hurt myself
deliberately once” and “During the past year, I hurt myself deliberately
more than once”.
Data analysis
Chi square tests and t-tests were conducted to compare sample
characteristics between migrant and urban children. Multiple linear
regression and binary logistic regressions models were applied to examine
the associations between the psycho-social outcomes and migrant-urban
status. Suicidal ideation and self-injurious behavior and SDQ outcomes were
included as dependent variables and migrant-urban status was examined as an
independent variable. Analyses were adjusted for age, gender, family
economic status, parents’ education level and parents’ marital status. All
analyses were performed using SPSS 20.0 version and assumed a statistical
significance level of p < 0.05.
Results
Table
1 presents the
differences in socio-demographic characteristics and the psychological outcomes
between migrant children and urban children. There were significantly more males
among migrant children (55.90%) than urban children (49.04%). The mean age of
migrant children was 13.67 (SD = 1.52) and the mean age of urban children was 13.92
(SD = 1.30). Migrant children had a generally lower family economic status
(
χ2 = 1031.00; p < 0.001), with parents who were
less educated compared to urban children (
χ2 = 576.80; p < 0.001). Compared to urban children’s
parents (6.45%), fewer migrant children’s parents (4.29%) were divorced (
χ2 = 9.24; p < 0.01).
Table 1The social-demographic characteristics, SDQ and SITBs of
migrant compared to urban children
Gender |
Male | 966 (55.90) | 1100 (49.04) | 18.41 | < 0.001 |
Female | 762 (44.10) | 1143 (50.96) | | |
Age, mean (SD) | 13.67 (1.52) | 13.92 (1.30) | 34.23 | < 0.001 |
Family economic status | 1031.00 | < 0.001 |
Poor | 566 (31.03) | 53 (2.26) | | |
Fair | 821 (45.01) | 711 (30.35) | | |
Wealthy | 437 (23.96) | 1579 (67.39) | | |
Parents’ education level | 576.80 | < 0.001 |
Illiteracy or primary school | 319 (17.68) | 89 (3.90) | | |
Middle school | 1100 (60.98) | 975 (42.71) | | |
High school | 329 (18.24) | 754 (33.03) | | |
College or above | 56 (3.10) | 465 (20.37) | | |
Are your parents divorced? | 9.24 | 0.003 |
Yes | 79 (4.29) | 151 (6.45) | | |
No | 1761 (95.71) | 2189 (93.55) | | |
Total difficulties, mean (SD) | 12.28 (5.19) | 11.12 (5.56) | 47.84 | < 0.001 |
Emotional symptoms, mean (SD) | 3.09 (2.00) | 3.03 (2.12) | 7.40 | 0.007 |
Conduct problems, mean (SD) | 2.43 (1.63) | 2.18 (1.60) | 4.43 | 0.035 |
Hyperactivity, mean (SD) | 3.92 (2.16) | 3.36 (2.20) | 6.17 | 0.013 |
Peer problems, mean (SD) | 2.84 (1.60) | 2.55 (1.65) | 2.73 | 0.098 |
Prosocial behavior, mean (SD) | 6.93 (2.02) | 7.39 (2.10) | 53.35 | < 0.001 |
Internalizing problems, mean (SD) | 5.93 (2.88) | 5.58 (3.06) | 65.81 | < 0.001 |
Internalizing problems (> 8) | 326 (17.55) | 418 (17.72) | 0.02 | 0.903 |
Externalizing problems, mean (SD) | 6.35 (3.30) | 5.54 (3.30) | 81.15 | < 0.001 |
Externalizing problems (> 10) | 1796 (96.66) | 2231 (94.57) | 10.54 | 0.001 |
Suicidal ideation | 1.70 | 0.200 |
Yes | 492 (26.67) | 584 (24.89) | | |
No | 1353 (73.33) | 1762 (75.11) | | |
Self-injuries behavior | 4.86 | 0.030 |
Yes | 189 (10.47) | 193 (8.45) | | |
No | 1616 (89.53) | 2091 (91.55) | | |
Migrant children had significantly higher mean scores for total
difficulties (t = 47.84, p < 0.001),
internalizing problems (t = 65.81; p < 0.001)
and externalizing problems (t = 81.15;
p < 0.001), and lower mean scores on the prosocial behavior scale (t = 53.35; p < 0.001) compared to urban children.
Migrant children reported significantly higher rates of self-injurious behaviors
(χ2 = 4.86; p < 0.05).
Table
2 shows the linear
regression analyses of SDQ outcomes and the binary logistic regression analyses of
SITBs outcomes. After controlling for gender, age, family economic status, parent’s
education level and parents’ marital status, migrant children scored higher for
total difficulties (β = 0.46; 95% CI = 0.06, 0.85; p < 0.05) and externalizing
problems (β = 0.50; 95% CI = 0.26, 0.74; p < 0.001) than did urban children.
Migrant children reported significantly higher rates of suicidal ideation
(OR = 1.23; 95% CI = 1.03, 1.46; p < 0.05) and self-injurious behaviors
(OR = 1.32; 95% CI = 1.01, 1.72; p < 0.05).
Table 2Regression coefficients for SDQ outcomes and SITBs on
children group with adjustment for socio-demographic
characteristics
Group |
Urban children | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
Migrant children | − 0.09 (− 0.24, 0.07) | 0.15 (0.03, 0.27)* | 0.35 (0.19, 0.51)*** | 0.04 (− 0.08, 0.16) | − 0.05 (− 0.27, 17) | 0.50 (0.26, 0.74)*** | − 0.10 (− 0.25, 0.05) | 0.46 (0.06, 0.85)* | 1.23 (1.03, 1.46)* | 1.32 (1.01, 1.72)* |
Gender |
Male | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
Female | 0.36 (0.23, 0.49)*** | − 0.40 (− 0.49, − 0.29)*** | − 0.45 (− 0.59, − 0.32)*** | − 0.36 (− 0.46, − 0.25)*** | 0.01 (− 0.18, 0.19) | − 0.85 (− 1.00, − 0.64)*** | 0.61 (0.48, 0.74)*** | − 0.84 (− 1.17, − 0.51)*** | 1.11 (0.97, 1.30) | 1.09 (0.87, 1.36) |
Age | 0.08 (0.03, 0.12)** | 0.02 (− 0.02, 0.06) | 0.17 (0.12, 0.22)*** | 0.01 (− 0.03, 0.04) | 0.08 (0.01, 0.15)* | 0.19 (0.12, 0.27)*** | − 0.01 (− 0.05, 0.04) | 0.27 (0.15, 0.39)*** | 1.22 (1.16, 1.29)*** | 1.11 (1.02, 1.20)* |
Family economic status |
Poor | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
Fair | − 0.19 (− 0.40, 0.02) | 0.05 (− 0.11, 0.21) | − 0.04 (− 0.25, 0.18) | − 0.19 (− 0.35, − 0.03)* | − 0.38 (− 0.68, − 0.09)* | 0.02 (− 0.31, 0.34) | 0.17 (− 0.03, 0.38) | − 0.36 (− 0.89, 0.17) | 1.09 (0.87, 1.38) | 0.83 (0.59, 1.17) |
Wealthy | − 0.24 (− 0.46, − 0.02)* | − 0.30 (− 0.20, 0.14) | − 0.20 (− 0.43, 0.03) | − 0.38 (− 0.55, − 0.21)*** | − 0.62 (− 0.93, − 0.30)** | − 0.23 (− 0.58, 0.12) | 0.50 (0.29, 0.72)*** | − 0.85 (− 1.42, − 0.28)** | 1.29 (1.01, 1.65)* | 1.07 (0.74, 1.54) |
Parents’ education level |
Illiteracy/primary school | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
Middle school | − 0.43 (− 0.64, − 0.22)*** | − 0.26 (− 0.42, − 0.09)** | − 0.33 (− 0.55, − 0.11)** | − 0.27 (− 0.43, − 0.10)** | − 0.69 (− 0.99, − 0.39)*** | − 0.59 (− 0.91, − 0.26)** | 0.32 (0.11, 0.52)** | − 1.28 (− 1.82, − 0.74)*** | 0.68 (0.54, 0.85)** | 0.73 (0.53, 1.01) |
High school | − 0.45 (− 0.69, − 0.22)*** | − 0.24 (− 0.42, − 0.06)** | − 0.44 (− 0.68, − 0.19)*** | − 0.34 (− 0.52, − 0.15)*** | − 0.79 (− 1.13, − 0.45)*** | − 0.68 (− 1.05, − 0.31)*** | 0.49 (0.26, 0.72)*** | − 1.47 (− 2.07, − 0.86)*** | 0.68 (0.53, 0.88)** | 0.69 (0.47, 1.02) |
College or above | − 0.78 (− 1.06, − 0.50)*** | − 0.40 (− 0.61, − 0.18)*** | − 0.82 (− 1.11, − 0.53)*** | − 0.61 (− 0.83, − 0.39)*** | − 1.39 (− 1.79, − 0.99)*** | − 1.22 (− 1.65, − 0.77)*** | 0.77 (0.50, 1.04)*** | − 2.60 (− 3.32, − 1.88)*** | 0.74 (0.54, 1.02) | 0.90 (0.58, 1.40) |
Parental martial status |
Married | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
Divorced | 0.26 (− 0.02, 0.54) | 0.36 (0.14, 0.57)** | 0.58 (0.29, 0.88)*** | 0.15 (− 0.07, 0.37) | 0.41 (0.01, 0.82)* | 0.94 (0.50, 1.38)*** | − 0.12 (− 0.39, 0.16) | 1.35 (0.63, 2.08)*** | 1.70 (1.27, 2.28)*** | 1.32 (0.86, 2.04) |
Discussion
As China’s economy grows, migrant populations will continue to expand.
Migration is a carefully weighed family decision [
23]. While migrant children may benefit from staying with their
parents, their well-being may be harmed from limited access to social welfare and
other social services [
24]. This study
sought to explore the mental health status and SITBs in migrant children living in
eastern coastal China in comparison to their urban counterparts. We found that
migrant children, compared to urban children, are more likely to experience
externalizing problems (conduct problems and hyperactivity) and SITBs (suicidal
thoughts and behaviors).
Partly in line with our first hypothesis, after controlling for
socio-demographic variables, migrant children reported higher mean scores in total
difficulties and externalizing problems (conduct problems and hyperactivity)
compared to urban children but not in internalizing problems (emotional symptoms and
peer problems). Low familial socioeconomic status (SES) is one of the several
environmental adversities that has been found to increase the risk of mental health
problems in this age group [
25,
26]. Coleman [
27] has proposed that three types of capital
influence youth’s well-being: parents who are educated (human capital) are assumed
to have a better economic status (financial capital) and are more likely to be
communicative with their children (social capital). Under this framework, our
findings suggest that better family economic status and parental education levels
can mitigate against the adverse psychological experiences caused by migration with
parents, indicating that material and family support can work as important factors
supporting children’s psychological well-being. Essentially, migrant children from
lower-income families with less-educated parents are susceptible to additional risks
for psychosocial disadvantages.
Previous studies also have suggested that SES is more closely related
to the externalizing than to the internalizing domain [
28,
29]. As a possible explanation for this, some scholars suggest
that, as children age, they become more exposed to influences outside of the family,
which may reduce their internalizing problems [
30]. Migrant and urban children in our study were close in age
and lived in similar neighborhoods, which may explain why migrant children in our
study didn’t report higher mean scores of internalizing problems (emotional symptoms
and peer problems) than did their urban counterparts.
Previous studies have suggested that externalizing problems (conduct
problems [
31,
32] and hyperactivity [
33]) in youth are associated with low family
cohesion and the low intellectual/cultural orientation of the family. Families with
low levels of intellectual/cultural orientation can only offer limited opportunities
for socialization and access to community resources to their children, which may
increase children’s externalizing problems [
34]. Likewise, the strong negative influence of parental divorce
highlights the importance of family cohesion on children’s mental health
[
35]. Parental divorce will impair
the bonds between family members, which may exert negative influences on a child’s
development of children.
After adjusting for relevant variables, migrant children reported
significantly higher rates of suicidal ideation and self-injurious behaviors than
did urban children in the present study, supporting our second hypothesis. As noted,
externalizing problems are associated with SITBs in adolescents [
36,
37]. The risk of suicide is 30–50 times higher in populations
with SITBs than in the general population [
38]. Thus, migrant children with suicidal ideation or
non-suicidal self-injurious behaviors are at high risk for suicide. In recent years,
a growing number of scholars have argued that the existing measures being
implemented for youth suicide prevention do not have the same efficiency in migrant
children as they do in urban children [
39], as migrant workers are too busy to take care of their
children [
40] and migrant-exclusive
schools are usually under-provisioned. Therefore, to prevent suicide among migrant
children more effectively, greater importance should be attached to their SITBs and
appropriate follow up management should be implemented.
Several limitations in the present study were identified when
interpreting the study findings, in light of its design and methodological
characteristics. Firstly, the sample size was large, yet the study was conducted in
a single district within one eastern coastal city of China. Therefore, it is
inappropriate to extrapolate the results to the whole country. Secondly, to
understand the condition of mental health and SITBs of migrant children, more
factors should be taken into consideration, including domestic violence and parents’
history of mental illness. Adolescents who have experienced family violence were at
higher risk of developing externalising problems [
41]. Since young children may be reluctant to answer some of
these questions, we didn’t include them in the questionnaire. Thirdly, our exclusive
reliance on adolescents’ self-reporting may result in the under-reporting of mental
health problems [
6]. Consequently,
mental health problems and SITBs may be underestimated in the present study.
Authors’ contributions
JL analyzed and interpreted the data; and drafted the manuscript. FW and DW
drafted the manuscript. PC participated in the coordination of the study. LL
participated in critical review of the manuscript; and participated in the
conception and design of the study. XZ participated in critical review of the
manuscript; and participated in the conception, design and coordination of the
study. All authors read and approved the final manuscript.