Acculturative Stress and Influential Factors among International Students in China: A Structural Dynamic Perspective

Stress represents a prominent aspect of modern life and is associated with numerous negative health consequences. International students are a key force in shaping globalization. However, these students often experience acculturative stress, influencing their health and well-being. The growing number of international students in China emerges as a new global health challenge and presents an opportunity to advance our understanding of acculturative stress. This study aims to investigate the acculturative stress of international students in China, and verify the mechanism and influential factors of acculturative stress. We analyzed survey data from 567 international students attending universities in Wuhan, China. We used a network-based analytical approach to assess the structure of the Acculturative Stress Scale for International Students and used regression analysis to assess the relationships between acculturative stress and theoretically related factors. We found that higher levels of acculturative stress were reported by students from Asia and Africa than from other regions (Europe/America/Oceania). Lower acculturative stress was reported by unmarried students than others and by students well prepared than not well prepared. We verified seven acculturative stress subconstructs: rejection, identity threat, opportunity deprivation, self-confidence, value conflict, cultural competence, and homesickness; and discovered a three-dimensional network structure of these subconstructs. Our results suggest that acculturative stress was more common among international students in China than in developed countries. Acculturative stress was also more common among international students who did not well prepared, married, and belonged to an organized religion. African and Asian students' stress was higher than that for students from other regions. Acculturative stress prevention programs should seek to improve preparedness of the international students for studying abroad and pay extra attention to the high risk subgroups.


Introduction
Stress represents a prominent aspect of modern life [1]. Both acute and chronic stressors have been associated with a number of negative health consequences, including ischemic heart disease, hypertension, cancers, diabetes, neurodegenerative diseases, depression, substance use, eating disorders, suicide, and other health problems [2]. Stress exposure may cause heart dysfunction by altering the balance between the vagal and sympathetic systems [3]. Stress can also cause protein misfolding in brain cells, activating a cascade of deleterious molecular events that disturbs normal cell functioning, leading to emotional and neurological diseases [4].
Acculturative stress -the process of confronting challenges in cross-cultural exchange settings -is a specific form of stress that represents a growing threat to the health of many populations, particularly international students, as the pace of globalization continues to accelerate [5,6]. While studying to develop them-selves, international students also serve as living bridges for exchanging knowledge, techniques, culture, and lifestyles across the globe [7]. In addition to contributing to economic globalization, these pioneers play a leading role in promoting global health. At the same time, researches indicate that due to difficulties in adapting to a new social and cultural environment (i.e., acculturative stress), stress-related physical, psychosocial, and behavioral problems are prevalent among international students [5,7].
Acculturative stress has traditionally been investigated among various mobile populations in developed countries [8,9]. Along with the rapid economic development, China's international student population has risen dramatically in the past two decades. China is now hosting approximately 328,000 students from more than 200 countries and regions across the globe [10]. While most international students studying in developed countries are from developing countries; the international student population in China includes those from both developed and developing countries [10]. The Chinese socioeconomic and cultural settings, the diverse origins and the growing number of international students in China create a window of opportunity to investigate acculturative stress in a novel region.
International students frequently jointly experience rejection, identity threat and opportunity deprivation [7,17]; researchers have shown these three constructs to be highly correlated with each other [17,18]. Together, they form assaultive socio-environmental barriers to smooth acculturation, leading to stress. Another three highly correlated components, adequate competence for crossculture communication, avoidance of value conflict, and adequate self-confidence, form a protective fortress against stress [12,16,17]. International students often report homesickness [7]; however, acculturation theory suggests that homelessness may become stressful in and of itself only after protective coping mechanisms fail [12]. Our primary goal in this study is to test the dynamic structure of the seven components of acculturative stress.
Researchers have documented several potential risk and protective factors of acculturative stress. Study findings from international student samples in developed countries suggest that lack of preparedness [19], shorter length of stay [20], lower language competency [21], greater cultural dissimilarity [7], lower educational attainment [22], and lower income [7] were important influential factors. Age [23], religion [24], and marital status [7] have been inconsistently related to acculturative stress. We do not know whether and to what extent any of these factors are also related to acculturative stress among international students in China.
In this study, we addressed the following four aims: (1) To document acculturative stress among international students in China with the published Acculturative Stress Scale for International Students (ASSIS); (2) to empirically verify the seven subconstructs derived from ASSIS; (3) to investigate potential underlying dynamics of acculturative stress by relating the seven subconstructs with a network-based analytical approach; and (4) to examine both protective and risk factors associated with acculturative stress, including the overall level and the individual subconstructs.

Ethics Statement
The survey protocol was approved by the Institutional Review Board at Wuhan University, China, and the survey data analysis was approved by the Human Investigation Committee at Wayne State University, USA.

Participants and Sampling
For this study, we recruited international students who were attending colleges and universities in Wuhan, China without Chinese citizenship. Wuhan, the provincial capital of Hubei Province, is located in central China by the Yangtze River with a total population of more than nine million and per capita GDP of $10,335 in 2011. Wuhan is also known as a university city, hosting 79 colleges and universities. Government statistics indicate that 11,932 international students from 161 countries were enrolled in colleges and universities in Wuhan in 2012. Participants were selected from the four largest comprehensive universities, which accounted for 59% of the total international student population in Wuhan.
All international students in the participating schools were eligible to be included in the study. School administrators provided access to international students' classes. Students were recruited by class, the smallest organized unit for schooling in China. Different from international students in many western countries, the majority of international students in China take classes together with only their fellow international students. Recruitment and survey administration were carried out in a classroom immediately after students completed a class and did not have another class thereafter. Before survey administration, students were fully informed about the study.
All eligible students were encouraged to participate and data were collected only among those who agreed to participate by signing the informed consent. All students we approached agreed to participate and no one withdrew from the study early.

Data Collection and Processing
Data were collected using the International Student Health and Behavior Survey (ISHBS). We developed the instrument with previously validated measures. The ISHBS covers of demographic and general information, experiences of working and daily life, cultural adaption, acculturative stress, and other variables. Most participants completed the full survey in 30-45 minutes. Pilot testing with 51 international students indicated that the survey was easily understood and well accepted. Participants were offered the opportunity to complete the questionnaire in either English or Chinese. Preliminary analyses indicated no significant differences in the data collected with the Chinese version (n = 62) and the English version (n = 505) of the questionnaires for any variables used in this study.
The survey was conducted in the spring semester in 2012. Three trained senior-year graduate students recruited participants and distributed the questionnaires. To ensure confidentiality and privacy, participants sat in a classroom with at least one empty seat between any two students. The survey was anonymous. Participants were allowed to skip any questions they did not want to answer. After they completed the survey, participants sealed their questionnaire in an envelope we provided and dropped it into a locked box.
The data manually were entered into the computer with EpiData software by the data collectors. We used a double-entry protocol to minimize data-entry errors. Among the 630 completed questionnaires, 63 were excluded because of missing data on key variables, yielding a final sample of 567 (90%) participants.

Measures
Acculturative Stress. Acculturative stress was measured with the 36-item Acculturative Stress Scale for International Students (ASSIS) [12]. Several studies have reported Cronbach's a..90 for the ASSIS [12,21]. Participants indicated their level of agreement on a 1, strongly disagree, to 5, strongly agree, scale. Cronbach's a of our data was .93. Scale scores were computed by summing up item scores; larger scores indicated higher levels of acculturative stress.
Acculturative Stress Subconstructs. To further our understanding of acculturative stress, we identified seven independent but also logically connected subconstructs among the ASSIS items. We established the subconstructs through a team effort. We first proposed a number of constructs directly related to acculturative stress through intensive literature review, brainstorming, and group discussions. With a set of tentative subconstruct names, each researcher attempted to match individual ASSIS items with the proposed constructs independently, followed by group discussions to resolve discrepancies. The tentatively matching results were then subjected to intensive psychometric evaluation to fine-tune item-subconstruct match such that (1) the number of items per subconstruct were similar, (2) the Cronbach's a coefficient was maximized, and (3) data-model fit was optimized.
Key Influential Factors. Country/place of origin was assessed using the question: ''What is your nationality?'' Participants by country were grouped into Africa, Asia, and others (Europe, Americas, and Oceania) after an assessment of the frequencies across countries. Religious beliefs (five categories: none, Buddhist/Hindu, Christian, Muslim, and others) were assessed using a checklist. Length of stay in China was assessed using the question: ''How long have you been staying in China?'' (number of years and number of months). Level of preparedness for studying in China was assessed with, ''How could you rate your preparations for coming to China to study?'' rated on a 1, not at all well prepared, to 4, very well prepared, scale. We then collapsed responses into not well prepared (from not at all well and somewhat not well) and well prepared (from somewhat well and very well). Demographic factors were age (in years), gender (male or female), marital status (unmarried or others, including married, divorced, separated and other statuses), educational attainment before coming to China (undergraduate and graduate), and current major (four categories: science, literature/business/law, medicine, and others).

Statistical analysis
Systematic psychometric assessment was used to assess the ASSIS as a whole and its seven subconstructs. We evaluated item responses, internal consistency and reliability (Cronbach's a), and one-and two-level CFA (measurement modeling). For reliability analyses, Cronbach's a$.7 was set as acceptable, .8 as good; and .9 as great. For measurement modeling analyses, data-model fitting were assessed using the following four indices (and benchmarks): GFI (..9), CFI (..9), RMSEA (,.05) and Chisquare/df (,2) [25].
A network analysis approach [26] was applied to explore the relationship among the seven acculturative stress subconstructs. In this approach, we first computed the correlation coefficients for all pairs of the seven constructs. We then used a network graph to represent the relationship for any pairs with a moderate or higher level of correlation (r$.40).
In assessing factors associated with acculturative stress and its seven subconstructs, Student t-tests (two groups) and ANOVA (multi-groups) were used first. Significant results from the bivariate analysis (p,.1) were further verified with multiple regression models to control demographic and other covariates. Type I error was set at p,.05 (two-sided). All analyses were conducted using SAS version 9.3 (SAS Institute, Cary, NC).

Sample characteristics
The 567 participants came from 94 countries and regions across the globe. Participant characteristics are presented in Table 1. Nearly 60% of participants were men, 84% of the sample came from Africa or Asia, mean age was 23 years, and median age was 22 years. Just under one-quarter of the sample had prior graduate work before studying in China, almost 90% of the sample was unmarried, and Christian and Muslim were the most commonly reported religious beliefs. Most students were studying literature, business, law, or medicine. On average, students had been in China just over one year, and approximately three-quarters indicated feeling well prepared for studying in China. Table 2 indicates that the ASSIS overall was highly reliable and CFA analysis indicated that the model fit the data well (GFI = .90, CFI = .93, RMSEA = .04, and Chi-square/df = 1.89). The seven ASSIS subconstructs were: identity threat (IT), opportunity deprivation (OD), rejection (RJ), self-confidence (SC), cultural competence (CC), value conflict (VC), and homesickness (HS). Results from EFA indicated that these seven ASSIS subconstructs each is unidimensional and results from CFA indicated that the data fit a two-level measurement model very well (CFI = .93, GFI = .91, RMSEA = .04, and Chi-square/df = 1.90).

Acculturative stress and subconstructs
Internal relationships among the seven acculturative subconstructs Figure 1 displays the results of the network analysis. The thickness of a line linking two subconstructs is proportionate to the correlation coefficient's magnitude. The seven subconstructs formed a 3D triangle structure. The correlations among the first group of subconstructs (IT, OD, and RJ) at the outside triangle were the highest (r's..70); followed by the second group of three subconstructs (VC, CC, and SC) (.60,r,.70). Correlations among the remaining subconstructs varied from .42 to .65. In addition, the correlations were high between IT and VC, and between RJ and SC.
Factors associated with acculturative stress Data in Table 3 indicate that compared to students from other countries in Europe, America and Oceania, students from Africa and Asia scored significantly higher on ASSIS. Unmarried students reported significantly lower ASSIS scores than other students. Students who were not well prepared for studying in China scored significantly higher than well-prepared students.

Predictors of acculturative stress and subconstructs
Results from linear regression analysis in Table 4 shows that after controlling for covariates, country/place of origin (Africa and Asia) were positively associated with ASSIS score; being unmarried and preparedness for studying abroad were negatively associated with ASSIS scores. International students from Africa scored higher on all seven subconstructs than students from other countries. Students from Asia scored higher on rejection, value conflict, homesickness, self-confidence, and cultural competence than students from other countries. Buddhist/Hindu students scored higher than those who reported not being part of an organized religion on cultural competence, and Christian and Muslim students scored higher than others on homesickness. Unmarried students scored lower than others on value conflict and cultural competence. Lastly, preparedness was associated with all subconstructs except value conflict and homesickness.

Discussion
In this study, we analyzed survey data from a sample of 567 international students from 94 countries who were attending universities in China. We documented the acculturative stress level among these students, proposed and empirically validated seven subconstructs of acculturative stress, and characterized the underlying 3D relationship among these constructs. Finally, we investigated how demographic and personal factors related to the overall level of acculturative stress and its subconstructs.
Stress has been recognized as a universal predictor of morbidity and mortality of many diseases [2][3][4] and as a risk factor for tobacco smoking, alcohol misuse, drug use/abuse, and other risk behaviors [2]. Along with globalization and dramatic increases in the number of international students and other cross-country mobile populations, acculturative stress has emerged as a new challenge to global health. Our findings provide new data advancing our understanding of acculturative stress and supporting therapeutic and preventive measures for stress reduction. The same pattern regarding region-oforigin was also reported for international students studying in developed countries in Europe, America, and other regions [21,27]. Similar to acculturative stress observed in western countries [28], international students from African and other Asian countries in China reported higher level of acculturative stress than western countries. Since China is a typical Asian country and the cultural differences will be smaller between China and these Asian countries and larger between China and African countries. The high level of acculturative stress among the students from the other Asian countries suggest that differences in socioeconomic status rather the culture may play a larger role in acculturative stress while the increased level of acculturative stress among African students could be due to both socioeconomic status [7] and cultural factors sush as values of face and the ideology of individualism and collectivism [21]. Further research is needed to examine this issue.

Acculturative Stress Subconstructs
Two innovative findings of this study were (1) the empirical verification of the seven subconstructs of acculturative stress: rejection, opportunity deprivation, identity threat, self-confidence, cultural competence, value conflict, and homesickness and (2) the discovery of the 3D network structure of these constructs. These findings are of great significance because they illustrate the key components of and the inner dynamics of acculturative stress.  Rejection, opportunity deprivation and identity threat are three key mutually correlated components of acculturative stress. These components reflect the impact of highly correlated [17,29] and most important external stressors [12,22]. To treat and to prevent deleterious effects of acculturative stress on health, therapists and public health interventionists must first focus on these three stressors.
Inside the three external stressors is the second triangle of ASSIS subconstructs. These components reflect both intrapersonal (self-confidence and cultural competence) and interactive (value conflict) sources of stress. Lack of self-confidence and cultural competence -and frequent culture value conflict -have been recognized as stressors [6,15,30]. Homesickness is the last subconstruct; it showed relatively weaker but broad connections with the other subconstructs. These findings are also informative for stress reduction. When confronting international students' stress, in addition to the three external stressors described above, therapists should discuss value conflict and attend to selfconfidence and cultural competence. Homesickness is present, but comparatively the impact of this subconstruct is more independent. A correction of homesick may not lead to significant reductions in other components of acculturative stress.

Risk and protective factors of acculturative stress
In this study we found three factors associated with higher levels of acculturative stress: lack of preparedness for studying abroad, being married, and having a religion. Preparedness has long been recognized as a protective factor of acculturative stress [19]. Its significance cannot be overemphasized in acculturative stress prevention. Interestingly, our findings suggest that being unmarried may be a protective factor for international students. Compared to international students who are married, unmarried students may have more time to focus on successfully adjusting to the new culture and environment [7]. People with a specific religion may experience difficulties in finding partners and locations for religious activities, leading to stress [24]. These factors are also to be considered in planning for stress reduction and in therapeutic services to assist students in dealing with stress.