Immigration-specific stress and 24-hour movement behaviors among international nurses in Japan: a network and time-series network analysis using wearable device data

Abstract

Background

As a sharp increase in healthcare demand has led to a severe shortage of nurses in aging societies, international nurses become to play a crucial role in supporting healthcare systems. However, they often face immigration-specific stress that may influence their 24-hour movement behaviors, including physical activity, sedentary behavior, and sleep, as key determinants of health. Despite the importance of these behaviors, limited research has examined the complex interrelationships among 24-hour movement behaviors in this population. This study examined the interrelationships among 24-hour movement behaviors of international nurses working in Japanese healthcare organizations using wearable devices and explored the relationship between these behaviors and immigration-specific stress. The findings aim to inform interventions to promote healthier behavioral patterns and enhance patient safety within healthcare organizations.

Methods

A total of 43 international nurses working in Japanese healthcare organizations participated in this study. They wore a Fitbit Charge 5 device for 4 weeks to record their daily 24-hour movement behaviors. Upon completion of the tracking period, participants completed a questionnaire assessing immigration-specific stress. We employed network analysis to investigate the relationship between immigration-specific stress and 24-hour movement behaviors, and temporal network analysis to explore the internal interactions within 24-hour movement behaviors.

Results

International nurses exhibited insufficient sleep duration. Network analysis revealed that the ‘Not at home’ feeling (lack of sense of belonging), ‘Occupation’ disadvantages (occupational development inequities) and ‘Novelty’-related challenges (unfamiliarity with workplace norms and tasks) negatively related to sleep duration. ‘Novelty’-related challenges were also negatively related to moderate-to-vigorous physical activity (MVPA). Temporal network analysis further indicated that increased MVPA was beneficial in improving subsequent sleep duration.

Conclusion

This study highlighted that sleep duration in international nurses may be improved by enhancing their sense of belonging, eliminating occupational development inequities, and coping with novelty-related challenges. Specific measures include developing more inclusive immigration policies, career development opportunities and continuing education to support international nurses. Additionally, physical activity programs, along with support for novelty-related challenges, can promote appropriate levels of MVPA and further improve sleep duration.

Trial registration

Not applicable.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12912-025-03707-4.

Introduction

The recruitment of international nurses and accompanying challenges

In recent years, Japan has faced a severe shortage of nurses due to an aging population and a sharp increase in healthcare demand, with international nurses becoming the workforce to fill this gap [1, 2]. Based on 2024 statistics, there are 2,677 healthcare workers holding medical visas, of which 1,727 (65%) are Chinese, making them an essential part of Japanese healthcare organizations [3]. Although the recruitment of international nurses has alleviated nursing shortages to some extent, as immigrants, they continue to face unique challenges during their occupational integration, including loneliness, language barriers, limited career advancement, and workplace discrimination [4]. In 1998, Aroian et al. [5] proposed the Demands of Immigration model, identifying six immigration-specific stress sources in the immigrant adaptation process. This model has also been applied to international nurses, revealing that immigration-specific stress had negative impacts on international nurses’ job satisfaction, working performance, and safety attitudes [6–8].

In addition, although the findings are not for international nurses, studies show that compared with native residents, immigrants are generally more prone to poor sleep health and have a higher risk of sleep disorders [9–12]. Moreover, immigrants tend to engage in lower levels of physical activity (PA) and exhibit prolonged sedentary behavior (SB), both of which are strongly correlated with an increased incidence of mental and physical health issues [13]. These studies indicate that the unique stressors faced by immigrants in the host country not only directly impact their sleep and PA but may also place their mental health at long-term risk [14]. For international nurses, negative health consequences are also associated with the demanding nature of nursing work [15]. Therefore, understanding the PA, SB, and sleep duration of international nurses may provide valuable insights into their overall health status and inform strategies to address the adverse effects of immigration-specific stress and challenging work environments.

The importance of 24-hour movement behaviors

PA, including light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA), along with SB and sleep duration, collectively constitute the 24-hour movement behaviors and are not isolated; rather, they are interconnected in ways that jointly influence health outcomes [16, 17]. LPA involves light-intensity movements (e.g., slow walking, household chores), while MVPA includes more vigorous activities (e.g., jogging, stair climbing) that significantly raise heart rate and respiration [18]. MVPA is associated with multiple health indicators and may be related to the risk of multimorbidity [19]. Increasing one behavior (e.g., sleep duration) often necessitates a reduction in the duration of others (e.g., PA or SB) and vice versa [20].

Therefore, identifying the activity-sleep patterns in individuals not only helps to gain a more comprehensive understanding of their 24-hour movement behaviors but also provides a scientific basis for developing effective health interventions [21]. In recent years, research on 24-hour movement behaviors has gained increasing attention in the global public health field [21]. This trend is driven by the accelerated pace of modern life and increasing societal pressures, physical inactivity, prolonged sedentary time, and declining sleep quality [22–24]. By promoting positive behavioral patterns, the risk of chronic diseases can be effectively reduced, leading to improved overall health outcomes in the population [25].

The importance of 24-hour movement behaviors for nurses

Nursing is known for its high intensity and responsibilities. Because of frequent shift work, high job stress, and persistent psychological burdens, nurses often struggle to effectively manage their 24-hour movement behaviors [26]. For instance, excessive occupational stress prevents nurses from obtaining adequate rest leading to increased fatigue, impaired judgment, and decreased work performance [27–29], which significantly increases the risk of medical errors and threatens patient safety [30]. Furthermore, the nature of nursing work, which involves long hours of sitting, contributes to SB [31]. SB not only increases the risk of obesity, diabetes, and cardiovascular diseases but also may further deteriorate nurses’ physical condition, ultimately decreasing work efficiency [32, 33]. Nearly half of healthcare workers are at high risk for chronic diseases [34]. Investigating nurses’ 24-hour movement behaviors enables a more comprehensive understanding of how PA, SB, and sleep interact with one another, thereby providing more effective health management strategies, in turn to mitigate the negative health and occupational consequences [15].

Objectives and novelty of analytic approach

Based on the aforementioned background, this study aimed to investigate the 24-hour movement behaviors of international nurses in Japan and the relationship between PA, SB, sleep, and immigration-specific stress.

When assessing PA and SB levels, many studies rely on self-reported questionnaires rather than objective measurement tools such as wearable devices [35]. While questionnaires are convenient for large-scale data collection, the results are susceptible to subjective biases and recall errors [36]. In contrast, wearable devices are effective tools for objectively measuring sleep and PA data [37], with an accuracy rate as high as 96% [38]. Therefore, this study introduced the use of Fitbit wearable devices to objectively record international nurses’ PA, SB, and sleep duration, providing reliable data support for the comprehensive and accurate assessment of their 24-hour movement behaviors [39].

The relationship between PA, SB, sleep, and immigration-specific stress is multidimensional and complex. The dynamic interconnections among these factors make it challenging for traditional methods such as linear regression and correlation-based analyses to effectively reveal the underlying mechanisms, and to identify clear intervention directions [40]. To overcome this challenge, this study employed network analysis to examine granular relationships. Network analysis constructs nodes (representing variables) and edges (representing statistical relationships between variables), allowing for flexible exploration of the complex associations between them [41].

Additionally, considering the dynamic nature of PA, SB, and sleep duration, for which the movement behaviors of the previous day may influence the outcomes of the next day, this study further integrated temporal network analysis. Temporal network methods analyze changes in nodes and links over time, providing a systematic assessment of the dynamic characteristics of 24-hour movement behaviors [42]. This approach offers a new perspective on the temporal dependency of movement behaviors, and provides a scientific basis for optimizing intervention strategies.

As the first study to investigate the 24-hour movement behaviors of international nurses, this study assessed the actual status and combined effects of PA, SB, sleep duration, and immigration-specific stress, filling a research gap in the field. These findings provide evidence for healthcare organizations and policymakers to optimize occupational health management for international nurses, further contributing to nursing quality and patient safety.

Methods

Participants and recruitment

This study was conducted between May and September 2024. The participants initiated the experiment at their convenience after completing the necessary setup and calibration. Participants were recruited through social media platforms such as WeChat and X (Twitter), and through communities of international nurses working in Japanese healthcare organizations. Recruitment was further expanded using snowball sampling. To be eligible, participants had to meet the following inclusion criteria: (1) born and received basic nursing education outside Japan, (2) Registered Nurse in Japan, for which should have passed level N1 (the highest level) of the Japanese Language Proficiency Test and the Japanese National Nursing Examination, (3) currently employed in Japanese healthcare organizations, (4) no physical or mental disabilities, (5) willing to wear a wearable device, and (6) able and willing to provide written informed consent.

Measurement

24-hour movement behaviors

All study participants were provided with a Fitbit Charge 5 (Fitbit Inc., San Francisco, California, USA) and a pre-configured anonymous Fitbit account. The Fitbit Charge 5 is equipped with 3-axis accelerometer and photoplethysmography sensors that work together to monitor users’ movement and physiological patterns [43]. Daily PA levels are estimated using proprietary algorithms that combine accelerometer and photoplethysmography sensors data to calculate total daily active minutes, including both LPA, MVPA and SB [44]. Sleep duration is derived from periods of sustained inactivity, in combination with heart rate patterns and circadian rhythm cues detected by the photoplethysmography sensors and accelerometer [45].

On the day before data collection, the participant logged into the account, test-wore the device to ensure proper function, and received detailed verbal and written instructions on how to use the Fitbit Charge 5. Participants were instructed to wear it on their non-dominant wrists 24 h per day throughout the 4-week experiment period, only excepting charging, showering, or water-based activities. Although the Fitbit Charge 5 is water-resistant, we instructed participants to remove the device during showering or water-based activities to prevent damage or data loss. A fully charged Fitbit Charge 5 can last up to 7 days, and it typically takes about 1 to 2 h to reach a full charge [46].

In case of any technical issues or device malfunction during the experiment period, participants were instructed to immediately contact the researchers. If necessary, a replacement device was provided. In such cases, data collection was restarted from the beginning of the measurement period.

Participants were instructed to synchronize their data daily using the Fitbit app. The researchers monitored data compliance three times a day throughout the experiment period. At the end of the study period, the researchers downloaded the complete dataset from the Fitbit cloud platform. As a result of this rigorous monitoring protocol, participants wore the Fitbit Charge 5 for an average of 22.8 h per day. Assuming the un-wearing time mainly spent on charging, showering, or other water-based activities, all the collected data were determined valid and thus there was no missing data in the final dataset. LPA, MVPA, SB, and sleep duration were extracted for analysis.

Immigration-specific stress

The revised Japanese version of Demand of Immigration (DI) scale was adopted in this study to assess the sources of distress experienced by participants [6]. In the previous study among international nurses in Japan, the revised DI scale has been confirmed its acceptable to satisfied reliability (Cronbach’s α = 0.66–0.84) and good construct validity, as evidenced by the results of confirmatory factor analysis (comparative fit index = 0.90, Tucker-Lewis index = 0.89, root mean square error of approximation = 0.07) [6]. The scale includes 23 items under six dimensions: DI1 ‘Loss,’ DI2 ‘Not at home,’ DI3 ‘Occupation,’ DI4 ‘Novelty,’ DI5 ‘Language,’ and DI6 ‘Discrimination.’ The items are rated on a 6-point Likert scale (1 = very low, 6 = very high). The average score is calculated for each dimension, with higher scores indicating higher stress levels experienced during the reference period [6].

Participants were asked to reflect on immigration-specific stress in their personal lives and workplaces in Japan over the past 4 weeks (during the Fitbit Charge 5 monitoring period). Participants were specifically instructed to reflect on their experiences in Japan when responding to items related to ‘Loss’ and ‘Not at home.’ ‘Loss’ describes a sense of longing for familiar people, places, and belongings from their home country. ‘Not at home’ captures the feeling of being an outsider or unfamiliar with one’s surroundings. For items related to ‘Occupation,’ ‘Novelty,’ ‘Language,’ and ‘Discrimination,’ participants were asked to recall their experiences in the Japanese healthcare organizations. ‘Occupation’ concerns challenges such as reduced professional status, difficulty in securing a suitable job, and struggles in workplace adaptation. ‘Novelty’ describes unfamiliarity with workplace social norms and information gaps in various tasks. ‘Language’ pertains to difficulties in communication, including perceived inadequacies in Japanese proficiency as evaluated by colleagues or patients. ‘Discrimination’ reflects perceptions of participants experiencing unequal rights compared with native-born individuals. For the present study samples, all the six dimensions showed acceptable or satisfied reliability as Cronbach’s alphas ranging from 0.68–0.83 [47–49]. Please refer to Supplementary Material A for English translation of the questionnaire items.

Statistical analysis

To visually present the distribution of PA, SB, and sleep duration across a 24-hour period for all participants, a ternary plot was employed.

Additionally, a network analysis was performed using the qgraph and bootnet R packages to construct and evaluate the relationships between immigration-specific stress, duration of LPA, MVPA, SB, and sleep. Prior to estimating the network, we regressed out the effects of two potential confounders ‘Qualification years in Japan’ and ‘Years living in Japan.’ The residuals obtained from these linear models were subsequently used to estimate the network structure and centrality metrics. In the network, the blue and red lines represent positive and negative correlations, respectively, with the thickness and color saturation of the edges, indicating the strength of these associations [50]. To evaluate the accuracy of the edge weights, non-parametric bootstrapping was applied, with the precision of the edge weights determined using narrow 95% confidence intervals. A bootstrap difference test (1,000 bootstrap samples, α = 0.05) was conducted to assess differences in edge weights [51]. We calculated expected influence (EI) centrality to evaluate the importance of each node within the network [52]. In this metric, a node’s EI is the sum of the weights of all its incident edges, with both positive and negative values considered. Higher EI values signify greater centrality. One-step expected influence (EI1) represents the extent to which a given node influences its directly connected neighbors, while two-step expected influence (EI2) summarizes the node’ s influence that extends across up to two edges, encompassing both direct and indirect effects. In this study, EI1 was mainly applied to assess the direct influence of each node. The stability of EI was assessed using the correlation stability coefficient, which indicates the maximum proportion of cases that can be dropped from the sample while maintaining a correlation of at least 0.7 with the original centrality indices in 95% of bootstrap samples. In our study, the correlation stability coefficient for EI (0.605) and edge weights (0.512), exceeding the recommended threshold of 0.5 for acceptable stability and interpretability [51, 53], demonstrated sufficiently stable for interpretation. Centrality analysis was performed, with the results reported as standardized z-scores.

To investigate the temporal dynamics of the duration of LPA, MVPA, SB, and sleep duration over a 4-week period, a temporal network analysis was conducted using the multilevel vector autoregression model in R. Prior to model estimation, the Augmented Dickey-Fuller test was applied to assess the stationarity assumption required for temporal network analysis. All four variables of LPA, MVPA, SB, and sleep duration yielded p-values below 0.05, supporting the assumption of stationarity. The multilevel vector autoregression package was employed to construct the temporal network model [51], assuming a lag of 1 and applying linear mixed-effects regression to estimate time-based relationships among variables. This model assumed a correlated temporal structure and orthogonal contemporaneous relationships. Temporal network analysis was performed to assess Granger causality, and network visualizations were generated using the qgraph package. All networks were displayed with a circular layout, in which nodes represented variables and edge thickness indicated the strength of the relationships. Blue edges represented positive associations, whereas red edges indicated negative associations [50]. To further investigate the role of each variable in the network, centrality analysis was performed, with the results reported as standardized z-scores. Node influence was assessed through centrality measures, where instrength centrality represents the total weight of all incoming connections to a node, indicating how strongly it is influenced by others, and outstrength centrality denotes the total weight of outgoing connections, reflecting the extent to which a node acts as a source of activation in the network [50].

All statistical analyses were conducted using R Version 4.1.4.

Ethical considerations

This study was conducted in accordance with the ethical standards of the Declaration of Helsinki and was approved by the Ethics Committee of the Institute of Science Tokyo (Approval No. 2023219). After confirming the eligibility of the participants, the researchers provided a detailed explanation of the objectives and procedures of the study and assessed participants’ willingness to participate. Participation was entirely voluntary, and participants were assured that all personal information and data would be treated with strict confidentiality and privacy. Written informed consent was obtained from all participants. They were informed of their right to withdraw from the study at any time without penalty. Upon obtaining their agreement, the informed consent forms were mailed to the participants for their signature and subsequently returned to the researchers.

Results

Demographic characteristics

A total of 49 international nurses meeting the inclusion criteria agreed to participate in the study. During the study period, six participants withdrew for the following reasons: two participants experienced allergic reactions while wearing the Fitbit Charge 5, two participants were disapproved for participation by hospital management, one participant withdrew because of pregnancy during the study period, and one participant lost contact. Finally, data from 43 participants were included in the final analysis. Detailed demographic characteristics are shown in Table 1. Although there was no criterion for nationality, all the participants were Chinese.

Table 1.

Demographic characteristics of participants (N = 43)

Variable	N (%)
Gender
Female	38 (88.4)
Male	5 (11.6)
Age
20–29 y	14 (32.6)
30–39 y	28 (65.1)
≥ 40 y	1 (2.3)
BMI
< 18.5	5 (11.6)
18.5–25	37 (86.1)
> 25	1 (2.3)
Education level
Vocational school/Junior college	16 (37.2)
University (bachelor’s degree)	23 (53.5)
Graduate school (master’s or doctorate degree)	4 (9.3)
Residential Condition in Japan
Living alone	23 (53.5)
Living with friends	6 (13.9)
Living with family	14 (32.6)
Marital Status
Single	27 (62.8)
Married	16 (37.2)
Qualification years in Japan
< 5 years	20 (46.5)
5–10	21 (48.8)
> 10	2 (4.7)
Years living in Japan
< 5 years	2 (4.6)
5–10	33 (76.8)
> 10	8 (18.6)

24-hour movement behaviors

Figure 1 presents the ternary plot of 24-hour movement behaviors of the participants. In this study, participants spent the majority of their time in SB, averaging 10.9 h per day (48% of their total daily time). Their average sleep duration was 6.4 h per day (28%), while they engaged in PA for 5.5 h per day (24%). The sum of these three components equaled an average of 22.8 h per day as the wearing time, excluding time mainly spent on charging, showering, or other water-based activities.

Fig. 1.

Ternary plot of participants’ 24-hour movement behaviors

Network analysis of immigration-specific stress and 24-hour movement behaviors

Figure 2 shows the network model based on the cross-sectional data (network removed effects of ‘Qualification years in Japan’ and ‘Years living in Japan’). The analysis revealed that DI6 ‘Discrimination’ (EI1 = 1.22) and DI5 ‘Language’ (EI1 = 1.15) exhibited the highest EI within the network. These were followed by DI3 ‘Occupation’ (EI1 = 0.81), DI1 ‘Loss’ (EI1 = 0.49), DI4 ‘Novelty’ (EI1 = 0.46), and DI2 ‘Not at home’ (EI1 = 0.24). The remaining nodes of sleep duration (EI1 = − 1.45), SB (EI1 = − 1.16), MVPA (EI1 = − 1.02) were the nodes with the strongest negative influence. In addition, LPA (EI1 = − 0.74) demonstrated a moderate negative influence. Within the context of the connection between immigration-specific stress and 24-hour movement behaviors, stress from DI2 ‘Not at home’ feeling, DI3 ‘Occupation’ disadvantages, and DI4 ‘Novelty’-related challenges showed a negative connection with sleep duration, while DI4 ‘Novelty’ was also negatively associated with MVPA. Furthermore, DI6 ‘Discrimination’ demonstrated a positive connection with LPA. Refer to Supplementary material B (Figure S1-S5) for more detailed network analysis results.

Fig. 2.

Network analysis of immigration-specific stress and 24-hour movement behaviors

Temporal network analysis of 24-hour movement behaviors

Figure 3 illustrates the temporal network representing the dynamic relationships of 24-hour movement behaviors over time. In this network, nodes depict different time intervals (t), and the edges indicate the extent to which a given behavior predicts itself in the subsequent time interval (t + 1) or is predicted by other behaviors. The arrows represent the direction of the prediction. The results revealed a positive impact of MVPA on sleep duration, suggesting that longer MVPA durations predicted longer sleep durations the next day. Subsequently, longer sleep duration led to more LPA in the following day. Additionally, the temporal network revealed self-inhibitory effects for sleep duration and SB, suggesting that higher levels of these behaviors on a given day were associated with lower levels on the following day. The detailed results of the centrality plot, presented in Supplementary Material B (Figure S6), showed that MVPA exhibited the highest outstrength reflecting the highest source of activation in the network, while sleep duration had the highest instrength indicating mostly influenced by other behaviors.

Fig. 3.

Temporal network analysis of 24-hour movement behaviors

Discussion

This study is the first to explore the 24-hour movement behaviors of international nurses and the impact of immigration-specific stress on the 24-hour movement behaviors. Our findings revealed that immigration-specific stress, such as the ‘Not at home’ feeling and ‘Occupation’ disadvantages were negatively related to the sleep duration of international nurses. In addition, ‘Novelty’-related challenges were negatively associated with both MVPA and sleep duration. Moreover, we found that international nurses tended to experience insufficient sleep. However, increased participation in MVPA during the 24-hour movement behaviors could predict longer subsequent sleep duration.

Enhancing sleep duration in the context of 24-hour movement behaviors

This study indicated that the average sleep duration among international nurses was 6.4 h, which is shorter than the 7-hour minimum recommendation by the American Academy of Sleep Medicine and the Sleep Research Society for adults to promote optimal health [54]. This finding is consistent with reports on nurses’ short sleep durations in other countries [29]. Sleep is essential for human health and well-being and serves as a key physiological process for maintaining both physical and mental health [55, 56]. Insufficient sleep may compromise nurses’ work performance [30], posing a potential threat to patient safety [57].

From a psychological stress perspective, this study revealed a significant negative relationship between the ‘Not at home’ feeling of immigration-specific stress and sleep duration of international nurses. ‘Not at home’ refers to the feeling of being an outsider or stranger in an unfamiliar environment [5], which is commonly associated with a lack of belonging [58]. A lack of belonging can lead to feelings of loneliness [59], depression [60], and other psychosocial disorders, all of which may negatively impact mental health and physiological rhythms, leading to a reduction in sleep duration [61]. In addition, international nurses with lower levels of belonging in the host country are more likely to experience heightened stress recognition in the workplace, which may compromise patient safety [6]. These findings suggest that belongingness may not only influence the mental health and sleep duration of international nurses but also may have an impact on patient safety within healthcare organizations. Therefore, enhancing international nurses’ sense of belonging could improve their work performance and health. However, belongingness is not shaped solely by individual factors. Prior research has shown that the host country’s attitude toward the cultural adaptation of immigrants and its level of inclusiveness plays a critical role in shaping immigrants’ sense of belonging [62]. The degree of acceptance, support, and inclusivity of the host country significantly affects the psychological well-being and social integration of immigrants [63].

Our study also found that among the dimensions of immigration-specific stress, ‘Occupation’ disadvantages are connected with shorter sleep duration among international nurses. It has been reported that in addition to adapting to a high-pressure work environment, international nurses face additional challenges in their lives and work in their host countries [8]. Previous studies have shown that international nurses often encounter ‘Occupation’ disadvantages, including limited career advancement opportunities and a lack of professional recognition [64, 65]. These disadvantages have been linked not only to decreased job satisfaction and increased turnover intention, but also to compromised patient safety [8, 66]. It may also lead to increased job strain and burnout, potentially exerting a negative impact on sleep duration [67]. Therefore, eliminating the occupational disadvantages could also improve international nurses’ work performance and health.

In addition, our study found that ‘Novelty’-related challenges were negatively associated with sleep duration among international nurses. ‘Novelty’-related challenges may lead to increased physical fatigue during working hours [7], and previous research has shown that shorter sleep duration is positively associated with greater physical fatigue among nurses [68].

Enhancing PA and reducing SB in the context of 24-hour movement behaviors

The temporal network analysis indicated that MVPA could predict the subsequent sleep duration of international nurses, which in turn positively predicted LPA the following day. Given the fixed nature of 24 h in a day, increases in LPA, MVPA and sleep duration associated with reduction in SB as shown in the network model. In addition, the potential trade-off effect between LPA and MVPA was not observed in the network model that there was no direct connection between these two behaviors. This finding suggests that LPA and MVPA may operate independently, rather than competing for time within the daily activity structure.

While our study found that MVPA positively related to sleep duration of international nurses, this may be attributed to the stress-relieving effects of PA in high-demand work environments, which can help improve sleep duration. Sleep duration is an important element of sleep quality [69]. Koohsari et al. suggested that replacing SB with MVPA might help people achieve the recommended sleep requirements for optimal health [70]. Days with higher levels of PA are also generally associated with better sleep quality compared to less PA days [71]. However, our findings revealed that ‘Novelty’-related challenges was negatively associated with MVPA among international nurses. Nurses experiencing high ‘Novelty’-related challenges may perceive themselves as less capable of coping with everyday work demands, which in turn reduces their self-efficacy and subsequently diminishes their motivation to engage in MVPA [72, 73]. Therefore, improving sleep duration among international nurses may be achieved by increasing their MVPA participation, which could also be facilitated by reducing ‘Novelty’-related challenges.

Our study also found a positive correlation between ‘Discrimination’ and LPA among international nurses. Many international nurses have reported experiencing workplace discrimination [74–77]. According to the interview study after the experiment, several international nurses reported that as a kind of discrimination, they were allocated more physical workload than non-international nurses. Due to nursing work, participation in LPA (such as walking and lifting) is generally common [31, 78]. However, our study did not distinguish between work-related and non-work-related LPA. Therefore, it remains unclear whether the increased LPA observed among international nurses in the present study reflects an additional workload resulting from workplace discrimination.

In our study, SB was found to be negatively self-associated over time, which may reflect a sedentary compensation effect—where higher sedentary time on one day is followed by reduced sedentary time the next day. This pattern may be triggered by natural fluctuations in daily routines [79].

Implications for healthcare organizations and policymakers

First, enhancing the sense of belonging among international nurses in the host country may serve as crucial entry points for optimizing sleep duration. Therefore, it is recommended that healthcare organizations implement multicultural support programs, including cross-cultural adaptation training, and mental health counselling to help international nurses better integrate into their work and living environments. At the policy level, host country governments should develop more inclusive and targeted immigration policies to strengthen support for international nurses, such as providing equitable resources and assistance in housing security, family visits, and career development [6].

Second, healthcare organizations should implement equitable and transparent policies regarding career development opportunities and continuing education to mitigate occupational disadvantages faced by international nurses [80]. In addition, organizations should provide practical support systems to assist international nurses in overcoming work-related challenges. For instance, offering mentorship programs, or team-based problem-solving approaches when they encounter difficulties in fulfilling their job responsibilities. Hospital administrators and nurse managers must collaborate to improve the overall work environment, which is a fundamental prerequisite for ensuring the quality and safety of patient care [81].

Third, given that increased MVPA significantly predicted improved sleep duration among international nurses, healthcare organizations should adopt supportive measures to facilitate participation in MVPA. For instance, providing on-site fitness facilities, launching PA promotion programs, collaborating with local gyms to offer discounts, or implementing flexible work arrangements to overcome time and environmental constraints are potential strategies for implementing flexible work arrangements to overcome time and environmental constraints.

Limitations

This study has several limitations. First, the relatively small sample size and participants all obtaining Chinese nationality may limit the generalizability of the findings. Although we consider the sample size adequate for the current analyses and bootstrap procedures were applied to improve the robustness of the network estimates, the findings should be validated in future studies with larger and more varied samples.

Second, this study employed cross-sectional network analysis, which examined the relationship between immigration-specific stress and 24-hour movement behaviors, allowed for the identification of associations between variables but did not establish causal relationships. In the future studies, adopting a longitudinal study design could provide deeper insights into the dynamic relationships between immigration-specific stress and 24-hour movement behaviors.

Third, the study did not account for the departments/units in which participants worked. Since nurses’ 24-hour movement behaviors may vary depending on occupational roles and departmental demands, the lack of this information limits the ability to reveal potential variability.

Fourth, the 24-hour movement behaviors including PA and SB were measured as total daily values without distinguishing between work and non-work hours. Future studies should consider differentiating on-duty and off-duty time, accounting for departments/units, and comparing international and non-international nurses to provide a more precise understanding of activity patterns and contextual implications.

Conclusion

This study revealed that international nurses working in Japanese healthcare organizations experienced insufficient sleep and a need for greater participation in MVPA. Therefore, enhancing the sense of belonging and mitigating ‘Occupation’ disadvantages are critical for improving sleep duration among international nurses. Interventions should aim to reduce feelings of environmental unfamiliarity and offering equitable and transparent career development opportunities and continuing education policies. Additionally, since ‘Novelty’-related challenges negatively affects both MVPA and sleep duration, sustained workplace support and PA interventions may help optimize the 24-hour movement behaviors of international nurses. We hope that our findings could offer valuable insights for Japanese healthcare organizations and policymakers in developing targeted interventions that not only improve the overall health status of international nurses but also ensure nursing performance.

Supplementary Information

Below is the link to the electronic supplementary material.

Abbreviations

PA

Physical activity

SB

Sedentary behavior

LPA

Light physical activity

MVPA

Moderate-to-vigorous physical activity

DI

Demand of Immigration

EI

Expected influence

EI1

One-step expected influence

EI2

Two-step expected influence

WHO

World Health Organization

Author contributions

X.C. contributed to conceptualization, methodology, data curation, resources, formal analysis, and writing the original draft. X.G. contributed to conceptualization, methodology, validation, formal analysis, resources, review and editing, and funding acquisition. All authors reviewed and approved the final manuscript.

Funding

This work was partly supported by the Japan Society for the Promotion of Science (grant number 24K07926). We also acknowledge the Publication Activity Support of the School of Engineering, Institute of Science Tokyo, with support from the Micron Foundation.

Data availability

The datasets generated and/or analyzed during the current study are not publicly available due to privacy or ethical restrictions but are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

The study was approved by the Ethics Committee of Institute of Science Tokyo (Approval No. 2023219). All participants agreed to take part in the study and provided written informed consent prior to participation.

Consent for publication

All authors have approved the manuscript and agree with submission to BMC Nursing.

Competing interests

The authors declare no competing interests.