Previous research has identified the challenges and needs of international students during their higher education outside their native countries [1-6]. The most challenging issue faced by international students is adaptation to the new environment, especially the new culture of the host country [7-10]. Other challenges include difficult living circumstances; different foods, climate, cultural norms, and customs [2,8,11-14]; and stressful interactions with local students and the host environments [15]. International students also face academic or educational challenges such as an unfamiliar educational system and language barriers [2,8,11,16]. These stressors can lead to a kind of stress commonly referred as acculturative stress, defined as a psychological and physical discomfort experienced by an individual in a new cultural environment [17].

A causality relationship between a high level of stress experienced by international students and deteriorating health conditions and even more serious health problems has been reported [18,19]. The combination of lack of social relations, financial support, and stress results in students’ feelings of anxiety [5], depression, physical illness, and wasted potential [20-22], leading to depression [23], negatively affecting their academic achievements [24], reducing their academic performance, and even leading them to drop out of university [22,25], especially when it becomes excessive [19]. In this regard, preventing student dropout is a challenging task in higher educational institutions [26]. Pal [27] suggested that programs should be employed in higher educational institutions to address student levels of stress and intention to drop out. Furthermore, research has indicated there is a significant positive relationship between acculturative stress, social support, and sociocultural adjustment of international students [28]. Other studies reported a positive relationship between acculturative stress and psychological adjustment [29,30]. Acculturative stress was found to have a negative relationship with positive acculturation. Acculturative stress is negatively correlated with social support. Consequently, lower levels of acculturative stress are associated with both positive cultural associations and higher levels of social support [31], and acculturation is negatively associated with acculturative stress [32]. In terms of students’ social support and their adjustment, studies on international students in the Malaysian context [32-34] and overseas [28,35] reported that social support significantly affects international students’ adjustment by lowering the level of stress. Similarly, studies have found that social support has positive impacts on sociocultural adaptation as it acts against the stress of cultural adaptation of international students [36,37].

Malaysia has attracted many international students, which has positioned it 11th in world ranking in hosting international students [38]. The increasing number of international students coming from other regions, including the Middle East [39], and the plan to increase intake to 250,000 students by 2025 (Malaysia Education Blueprint 2015-2025: Higher Education) raises the need for enhancing the quality of services and enabling higher educational institutions to meet the needs and requirements of the students, especially in health care. The number of international students has increased from 18,242 to 83,633 in the years 2001-2013, however, making this a challenge. In addition, while the government aims to make the country of Malaysia an international hub for higher education excellence by 2020, research on international postgraduates is still limited. There are only a few studies on international postgraduates that explore the challenges they face in academic and social adjustment in Malaysia [40,41]. Cross-cultural adaptation is crucial for postgraduates in order to overcome the various challenges and become able to psychologically and socioculturally adapt to the new environment [42]. Acculturative stress is caused by stressors such as language barriers, academic barriers, racial discrimination [43,44], perceived surrounding environment, attitudes toward the host country among international postgraduate students [45], cultural shock, homesickness, and perceived hatred [46]. While Rajab et al [46] found that international students’ acculturative stress is moderate, Par et al [47] reported that almost 40% of international postgraduate students joining Malaysian universities experience a high level of acculturative stress, which could affect their academic achievement in higher educational studies [48].

Although the above studies in Malaysia are useful for investigation of international students’ acculturative stress, these studies have focused on describing stress merely from student perception and self-reported reflections, and they are scant and general in comparison with those studies carried out in other host countries [49]. For instance, while research on international student acculturative stress and adaptation has reached its third phase of development in other host countries like Australia [50], in the Malaysian context, such research is still in the early phase of development [49]. In addition, studies in the Malaysian context have ignored the importance of implementation of stress coping interventions. Further empirical investigations into issues pertaining to international student requirements are needed to enable students to improve achievement and performance in higher educational institutions [51]. Based on the above issues, gaps addressed in earlier research, and the need to address stress and adjustment in international students, our study proposes an educational intervention program that can assist international postgraduates to cope with and overcome the different aspects of acculturative stress.

The literature highlights several acculturation models developed by scholars over time, one of which is the bidirectional model of acculturation widely accepted in previous research [52]. Specifically, Berry’s model of acculturation [53] places emphasis on two distinct aspects: the person’s identification with their native culture and identification with the host culture. However, early views and perspectives of acculturation can be valuable in theoretically explaining and discussing the process of acculturation. According to the first view, acculturation is seen as a term covering issues resulting from first-hand contact of individuals with people of different cultural backgrounds. This view also stresses that the consequence of acculturation is changes in the individual’s native or original cultural patterns and behaviors. Based on this view, there is a distinction between acculturation and cultural change in the sense that acculturation encompasses such cultural change as one of its aspects, and assimilation, which is at times a phase of acculturation [54].

The second view emphasizes acculturation as a cultural change initiated by the conjunction of two or more autonomous cultural systems. Thus, acculturative change can result from direct cultural transmission or it can be a result of noncultural aspects, including modification of ecological or demographic characteristics by an impinging culture, and it may be delayed. Hence, acculturation can appear in the form of an internal adaption after the individual accepts alien cultural patterns or behaviors or it can emerge in the individual as a kind of reactive adaptation of traditional modes of life [54,55]. In addition, as defined by Graves [56], psychological acculturation is a process of changes taking place in an individual who participates in a culture-oriented contacting situation directly affected or influenced by the new or external culture and by the changing culture to which they belong. According to Redfield et al [57], acculturation comprises various changes in different forms, identified by Berry [58] as biological, social, and physical changes.

Based on the model of stress developed by Lazarus and Folkman [59], Berry [60] and Berry et al [61] developed an acculturative stress model. The main idea of the framework is that acculturative stress results from situations in which a person’s experiences and appraisal become problematic due to the person’s inability to deal with them and failure to adjust to them through behavioral changes. This implies that acculturative stress is a response of the individual to life events which are grounded in the experience of acculturation [54]. However, not all acculturation changes are assumed to lead to acculturative stress because how acculturation is experienced, perceived, and interpreted by the individual can be influenced by moderating and mediating factors, including personal characteristics such as age, gender, and social support prior and during acculturation [53,62].

In their systematic review of the theoretical frameworks used in research on international students’ sociocultural adaptation to host countries between 2012 and 2017, Sarmiento et al [63] found that 82.2% of the research papers and articles provided a description of particular theoretical frameworks on students’ adaptation. Moreover, 69.3% of these articles reported treating nonspecific frameworks. What was interesting in this review paper was that the majority of the reviewed research papers focused on investigation of international students’ issues related to acculturation and adaption based on the acculturation model. Acculturation should also be approached from the perspective of cross-cultural psychology. As pointed out by Berry [64], acculturation should be investigated in its cultural contexts. In such contexts, researchers can obtain a better understanding of the cultures and individuals in contact. Therefore, such investigation seeks to link the acculturation of a given group of people to which an individual belongs and the individual’s psychological acculturation.

Berry’s [65] acculturation model describes cross-cultural adaptation as a process that involves the individual’s or group’s behavioral and psychological changes in life resulting from their contacts with others from different cultures. Whereas psychological changes are related to one’s modified attitudes, perceptions, and beliefs, behavioral changes are pertinent to their external behavior toward those typical of the host society or mainstream [65]. In a previous study, the term psychological dimension was defined as the person’s perceived acculturative stress which was attributed to their cross-cultural adaptation (eg, how they perceived unfamiliar social cultural customs) [66]. On the other hand, psychological adaptation is often associated with the person’s emotional and affective satisfaction about their integration into a new social environment, while sociocultural adaptation encompasses the process in which the person fits in a new environment and effectively interacts with it [63]. Therefore, our study is framed within the theoretical perspective of acculturation and acculturative stress developed by Berry et al [61] and Berry [53] and further expanded by Berry [65,67,68].

This study aims to develop, implement, and evaluate the effectiveness of an educational intervention in reducing acculturative stress and improving adjustment among new international postgraduates joining Malaysian public universities. Specifically, the study aims to (1) describe participants’ sociodemographic characteristics, acculturation, acculturative stressors, and social support at the baseline; (2) determine the level of acculturative stress, adjustment (psychological and sociocultural), and intention to drop out of university among new international postgraduates at the baseline; and (3) determine the effect of the educational intervention on acculturative stress, adjustment, and intention to drop out between and within the control and intervention groups at the immediate and 3-month postintervention follow-up.

In order to achieve the above research objectives, the study attempts to test the following null research hypotheses: (1) the intervention group will score significantly higher than the wait-list group on the immediate and 3-month postintervention evaluation of acculturative stress, adjustment, and intention to drop out measures (between groups) and (2) the acculturative stress, adjustment, and intention to drop out scores for the intervention group at the immediate and 3-month postintervention follow-up will be significantly higher than scores of the baseline or preintervention (within groups).

The design, conduct, and reporting of the study will adhere to the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) [69], Consolidated Standards of Reporting Trials (CONSORT) guidelines [70], and Consolidated Standards of Reporting Trials of Electronic and Mobile Health Applications and Online Telehealth (CONSORT-EHEALTH) [71].

Malaysia is the context of this study since it is the host country for many international students coming from different countries. The target participants in this study will be those new international postgraduate students joining Malaysian public universities. The study includes 20 well-known public universities that attract large numbers of new international students who will be screened according to the inclusion criteria.

This study is quantitative in nature and experimental in design. Specifically, the study employs a cluster randomized controlled trial (RCT) design. Figure 1 summarizes the study design. Selection of such an experimental design is based on its strength and effectiveness [72]. A cluster design will be employed as the randomization and intervention at the level of the university, and the primary outcome measures are related to students’ acculturative stress, while the secondary outcomes refer to their adjustment and intention to drop out of university. Public universities will be randomized to either a control (wait-list) or intervention (educational intervention) group. In order to determine the effectiveness of the intervention program, the primary and secondary trial outcomes will be assessed through surveys of new international postgraduates at 3 time points: baseline (time 1) before the intervention, immediately postintervention (time 2), and at 3-month follow-up after the intervention (time 3).

Public universities that will be eligible to participate in the study should satisfy the following criteria: acting or serving as the main campuses for international students in Malaysia and having more than 40 new international postgraduates in their first semester in Malaysia. For students, only new international postgraduates entering the selected universities in their first academic semester will be eligible to participate.

For the purpose of eligibility assessment, the researcher will approach all public universities in Malaysia and invite only those universities that are eligible through formal invitation letters issued by the researcher’s university. The letters will be directed to the high authorities of the selected universities through emails seeking their permission for the researcher to conduct his study among international postgraduates. Moreover, the researcher will obtain lists of new international postgraduates joining these universities, including necessary information about the students including contact details, faculty, nationality, and academic program.

Procedures for recruiting public universities will be based on several strategies that have been reported to be useful for maximizing research participation, including prenotifying universities of the study, providing opportunities for participation, visiting persons in charge at the universities, contacting potential participants using telephone and other contact methods, accessing research staff for further clarification on participation, and using dedicated research staff to manage the recruitment process. Specifically, an invitation letter will be directed to a university contact person (deputy vice chancellor for academic and international affairs, deputy vice chancellor for research and innovation, and dean of postgraduate studies) in each eligible university.

Once the letters are sent, the above-mentioned persons in the universities will be contacted by telephone to confirm eligibility based on inclusion criteria and assess interest in participating in the study. This will be followed by several calls until the decision on informing international postgraduates of participation in the study is made and the researcher is informed of such decision. However, such decision, in some cases, will be made through meeting among academic and research staff and consultation with the management committee of a given university. At the end of this process, a confirmation email will be sent to each university, confirming and thanking them for agreement to participate in the study. Each participating university will be given hard and electronic copies of the information and invitation letters for the selected postgraduates in that university.

Student recruitment will use a random sampling procedure to select students from the list of the new postgraduates for each selected university based on probability proportional to size method in order to reduce possible sampling bias. The respondent’s information and consent sheets will be given to the sampled students to get their agreement to participate. In order to maximize response rates, representatives of the international students will be requested to seek the selected postgraduates’ consent.

Prior to randomization, the researcher will start collecting baseline data. This will be followed by assigning the universities as the unit of randomization. Universities will be randomized in order to reduce contamination between groups [73,74]. However, to ensure allocation concealment, the allocation sequence of the universities selected at the previous stage will be assigned to a control group and an intervention group by the ratio 1 to 1. The purpose of this is to ensure that the number of universities allocated to each group will remain approximately equal (see Figure 1 flowchart) [75-77]. This will be achieved by employing a simple randomization procedure. The researcher will use a computer-generated list of random numbers. It is exclusive to the researcher who will allocate the 10 universities to the two groups. In addition, no one in the control groups will know what the experimental groups will be offered. The statistician who will perform the primary analyses will be blinded to group allocation. This study will follow a CONSORT chart [73] as shown in Figure 1 (study flowchart).

The total sample size needed will be calculated by applying the formula for two population means [78] as seen in Figure 2. Means and standard deviation used for the intervention group and control group were based on the estimation offered in a previous RCT [79]: µ1=2.58, µ2=2.07, SD1=1.08, SD2=1.08, n1=24, n2=30. Therefore, the total sample (n) will account for 71 participants. Calculation of the required sample size in this study was performed based on the guidelines in the CONSORT for cluster RCTs [73]. By considering the account intraclass correlation coefficient (ICC), it is necessary to multiply the sample size in RCTs by design effect=1+(m–1)*ICC, where m is the average cluster size [80-83]. Thus, the average class size is assumed to be 40 participating students, and an ICC of .05 could be expected. This would result in design effect N=1+(m–1)*ICC=1+(40–1)*.05=2.95. Based on the sample size required by the formula, the required minimum sample size for each group after adjusting for design effect is n=71*2.95=209, and the total sample size required is 209 participants per arm.

To factor in 20% attrition, if (n) is the sample size required as per formula and (d) is the dropout rate, adjusted sample size N new is obtained as N1=n/(1–d) [84]. Therefore, the total required per group after adjusted for dropout rate is N1=209/(1–0.2)=261; hence, a total of 522 new international postgraduate students will be needed for the sample size in both groups.

This study will use a self-administered questionnaire consisting of 8 sections measuring the sociodemographic, independent, and dependent variables (study outcomes). The questionnaires will be completed at time 1, time 2, and time 3.

Prior to distributing the questionnaires to the targets of the study, the researcher conducted a pilot study as recommended by scholars to reduce ambiguity, validate the instrument, and evaluate the educational intervention program before conducting the study [138,139]. For the validation of the intervention module and educational materials, the researcher constructed the basis of each statement, information, guideline, or strategy in the educational module from credible published scientific sources. A panel of experts then engaged in reviewing all sources and the newly developed educational intervention before providing it to the study sample. The experts read the references used in developing the module and educational materials and were asked to provide their evaluation and suggestions for enhancement. This was followed by resending the final module to the panel of experts for a second review. This resulted into the final version of the educational module and educational materials that will be used in this study.

After the educational module and materials were designed, a group of experts in psychiatry and education (3 experts from the psychiatric department, faculty of medicine, and 3 from the faculty of education) rated the content validity of the educational module and materials from the proposed educational intervention in terms of its accuracy, currency, and appropriateness of content using a 5-point scale: 1=extremely unsuitable to 5=extremely suitable. They will be also asked to identify areas of items that need to be improved, removed, or modified [140]; we will then pretest the educational module and materials among new international students in a private university to evaluate the reliability of the educational module and materials.

We will use SPSS Statistics version 25.0 (IBM Corp) to analyze the data. Statistical significance will be considered as a P value of less than .05. Analysis of the data will take into account clustering of students within universities. The study will use statistical analyses, including descriptive statistics of the respondents’ sociodemographic characteristics, chi-square test for nonparametric variables, and 2-tailed t test for continuous variables, to compare between the control and intervention groups on sociodemographic variables and primary and secondary outcome measures. Complete case analyses, intent-to-treat analyses, and completer status analyses will be conducted according to the initial allocation of universities to either intervention or control groups. In relation to the missing data, we will follow the guidelines for analyzing and reporting cluster RCTs with missing data established by Fiero et al [141] and Díaz et al [142].

The effectiveness of the intervention will be assessed using the generalized estimation equation (GEE). Specifically, the differences in the research hypothesis in terms of students’ acculturative stress, adjustment (sociocultural and phycological), and intention to drop out will be compared at 3 points—time 1 (preintervention), time 2 (immediately postintervention), and time 3 (3-month follow-up)—between and within the intervention and the control groups adjusted for covariate variables. The GEE method was chosen because of its efficiency in appropriately modeling the structure of the correlations of the pre-post repeated measures and its low degree of reliance on the assumption of normality in the distributions of data for the variables in the analysis. Furthermore, in the context of RCT research, multilevel models such as the GEE are the most appropriate model because they permit the estimation of treatment effects (ie, group differences) across multiple time points within a single statistical model [143].

However, there is no default option in the GEE analysis for eta squared to obtain the intervention effect size that can be expressed as a standardized effect size. Therefore, two popular measures, Cohen d and eta squared, will be used in this study. Cohen d = beta ÷ standard deviation, with beta representing the difference between two means for the two groups relative to their standard deviation obtained from the pooled variance to compute the effect size within group and between group [144-146]. Hence, d = (mean 1 – mean 2) / (the average standard deviation of the two groups). The eta squared indicates how much of the total variance is explained by the difference between the means. Therefore, we will convert the effect size d to eta squared with the equation η²=d²/d²⁺⁴. The reported effect size d is also interpreted by Cohen [147] as adopted by many previous studies, specifically intervention as well in terms of the practical or clinical significance of the effect, 0.2 (small effect), 0.5 (moderate effect), and 0.8 (large effect), and similarly for eta squared 0.01 (small effect), 0.06 (moderate effect), and 0.14 (large effect) [146,148-151].

This study investigates acculturative stress, adjustment, and intention to drop out among new international postgraduates joining Malaysian public universities. Specifically, the focus of the study is on the effectiveness of a proposed educational intervention in reducing new international postgraduates’ acculturative stress in the host country of Malaysia. Due to the fact that Malaysia is becoming one of the important host countries for postgraduates in the Asian region, it is important to investigate acculturative stress and adaptation of new international postgraduates to the culture and environment. The study is expected to contribute to previous studies and existing knowledge about the challenges and barriers faced by postgraduates entering higher education in Malaysia. As an experimental study, the results will inform us of the stressors that cause acculturative stress and strategies that can be used by international postgraduates to adapt to the new environment. Another contribution of this study is the implemented intervention program that can be used as a guide for further studies among new international students. These results will provide good insight into this important research topic and be of value for international postgraduates, academics, authorities, policy makers in higher education, and researchers interested in exploring issues and challenges among postgraduates in different higher educational contexts.

This trial is expected to provide valuable insight into the implementation and effectiveness of educational intervention programs in reducing new international postgraduates’ acculturative stress and improving their adjustment to the host culture. The aim of designing the initial cluster RCT is also to provide information regarding the feasibility of potential future full-scale trials in order to optimize the intervention and design approach. Process evaluation outcomes will provide contextual information about implementation decisions of international students, researchers, and higher education stakeholders.