Introduction
Nurses, as the main part of the health system, have a fundamental role in continuing patient care. Married female nurses, in addition to having stressful jobs with high burnout, have to fulfill roles such as marital relationships and parenting. Therefore, this pressure, stress, and exhaustion are more evident in these nurses. To reduce these problems, there is a need to increase their resilience. In recent years, the positive psychology approach, emphasizing attention to individuals’ strengths and virtues, has been considered by researchers. Resilience refers to the ability to adapt during threats. It has a special place, especially in developmental psychology, family psychology, and mental health. This study aimed to develop a structural model to determine the relationship of resilience with cognitive flexibility and self-differentiation in Iranian married female nurses, mediated by marital intimacy and marital adjustment.

Methods
This is a descriptive-correlational study using structural equation modeling (SEM). The study population included all married female nurses working in public hospitals and medical centers in Alborz province, Iran, in 2022. A total of 400 eligible nurses were selected using a multistage cluster sampling method. The data collection tools were the Connor-Davidson Resilience Scale, Dennis and Vanderwal’s 25-item Cognitive Flexibility Inventory (CFI), Skowron and Smith’s 46-item Differentiation of Self Inventory-Revised (DSI-R), Bagarozi’s Marital Intimacy Needs Questionnaire (MINQ), and the Locke-Wallace Marital Adjustment Test (MAT). Descriptive statistics and SEM were used in SPSS v.26 and Amos v.24 for data analysis.

Results
Most of nurses were in the 20-25 age group (n=152, 38%), had a bachelor’s degree (n=265, 66.25%), with no children (n=144, 36%), up to 5 years of work experience (n=198, 49.5%), and up to 5 years of marriage length (n=166, 41.5%), and were living with their husbands (n=382, 95.5%). The mean scores of DSI-R, resilience, CFI, MINQ, MAT were 26.75±6.87, 26.98±6.74, 21.21±6.56, 23.70±6.03, and 25.23±6.40, respectively. 
The correlation matrix showed a positive and significant correlation between cognitive flexibility and resilience (r=0.792, P<0.001), between self-differentiation and resilience (r=0.729, P<0.001), between marital intimacy and resilience (r=0.732, P<0.001), and between marital adjustment and resilience (r=0.712, P<0.001). Therefore, it was possible to investigate the research model.
In assessing the fitness of the model, the root mean square error of approximation was less than 0.05, and comparative fit index, adjusted goodness-of-fit index, incremental fit index, goodness of fit index, normed fit index, relative fit index, and un-normed fit index were all greater than 0.90, indicating the appropriate fit of the model. The path coefficient between cognitive flexibility and resilience was 0.986; between self-differentiation and resilience, 0.842; between marital adjustment and resilience, 0.578; and between marital intimacy and resilience, 0.909, all of which were more than 0.5. 
In order to evaluate the mediation effect, a bootstrap test was used. The path coefficients for the direct and indirect relationship between cognitive flexibility and resilience through marital adjustment were 0.671 and 1.228; for the direct and indirect relationship between cognitive flexibility and resilience through marital intimacy, -0.980 and 1.228; for the direct and indirect relationship between self-differentiation and resilience through marital adjustment, 1.098 and -0.216; and for the direct and indirect relationship between self-differentiation and resilience through marital intimacy, 0.892 and -0.216, respectively. All path coefficients were significant.

Conclusion
Cognitive flexibility and self-differentiation are correlated with resilience in married female nurses. Marital intimacy and marital adjustment can mediate their relationships. Therefore, it can be stated that marital intimacy and marital adjustment are effective factors for increasing the resilience of flexible and self-differentiated married female nurses. 

Ethical Considerations

Compliance with ethical guidelines
Participants in the study were assured that their information would be kept confidential. The informed consent form was signed by all participants. This research has ethical approval from the Ethics Committee of Alborz University of Medical Sciences (Code: IR.ABZUMS.REC.1401.297).

Funding
This article was extracted from the PhD dissertation of Mohsen Kamalinia at the Department of Psychology, Faculty of Humanities, Islamic Azad University, Saveh Branch. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for profit sectors.

Authors' contributions
Conceptualization: Kianoush Zahrakar and Mohsen Kamalinia; Methodology and sampling: Mohsen Kamalinia and Mehdi Arbazadeh; Data analysis, writing, editing & review: All authors.

Conflict of interest
The authors declare no conflict of interest.

Acknowledgments
The authors would like to thank all nurses who participated in this research for their cooperation.



 

1. Beckman CM, Stanko TL. It takes three: Relational boundary work,resilience, and commitment among navy couples. Acad Manage J. 2020; 63(2):411-39. [DOI:10.5465/amj.2017.0653] 
2. Tahir K, Khan N. Mediating role of body image between sexual functioning and marital intimacy in Pakistani women with breast cancer. Psychooncology. 2021; 30(2):260-6. [DOI:10.1002/pon.5563] [PMID] 
3. Miller K, Kelly A. Is self-compassion contagious? An examination of whether hearing a display of self-compassion impacts self-compassion in the listener. Can J Behav Sci. 2020; 52(2):159-70. [DOI:10.1037/cbs0000150] 
4. Du W, Luo M, Zhou ZA. Study on the relationship between marital socioeconomic status, marital satisfaction, and depression: Analysis based on actor-partner interdependence model (APIM). Appl Res Quali Life. 2022; 17:1477-99. [DOI:10.1007/s11482-021-09975-x] 
5. Fahimdanesh F, Noferesti A, Tavakol K. Self-compassion and forgiveness: Major predictors of marital satisfaction in young couples. Am J Fam Ther. 2020; 48(3):221-34. [DOI:10.1080/01926187.2019.1708832] 
6. Frye N, Ganong L, Jensen T, Coleman M. A dyadic analysis of emotion regulation as a moderator of associations between marital conflict and marital satisfaction among first-married and remarried couples. J Fam Issues. 2020; 41(12):2328-55. [DOI:10.1177/0192513X20935504] 
7. Abe S, Oshio A. Does marital duration moderate (Dis) similarity effects of personality on marital satisfaction? SAGE Open. 2018; 8(2):2158244018784985. [DOI:10.1177/2158244018784985] 
8. Ifeoma Odinka J, Nwoke M, Chukwuorji JC, Egbuagu K, Mefoh P, Ndukuba AC, et al. Dependent personality, mindful awareness, and marital satisfaction and their association with postpartum psychological distress in two tertiary hospitals, southeast nigeria. J Health Care Poor Underserved. 2020; 31(2):920-38. [DOI:10.1353/hpu.2020.0069] [PMID] 
9. Domaradzka E, Fajkowska M. Cognitive emotion regulation strategies in anxiety and depression understood as types of personality. Front Psychol. 2018; 9:856. [DOI:10.3389/fpsyg.2018.00856] [PMID] [PMCID] 
10. Vazquez V, Otero I, Goodlow J. Relationship stigma and black-white interracial marital satisfaction: The mediating role of religious/spiritual well-being. Ment Health Relig Cult. 2019; 22(3):305-18. [DOI:10.1080/13674676.2019.1620189] 
11. Riahi, F., Golzari, M., & Mootabi, F. The relationship between emotion regulation and marital satisfaction using the actor-partner interdependence model. Iran J Psychiatry Clin Psychol. 2020; 26(1):44-63. [DOI:10.32598/ijpcp.26.1.3038.1] 
12. Martin RC, Dahlen ER. Cognitive emotion regulation in the prediction of depression, anxiety, stress, and anger. Pers Individ. 2005; 39(7):1249-60. [DOI:10.1016/j.paid.2005.06.004] 
13. Peixoto-Freitas J, Rodríguez-González M, Crabtree SA, Martins MV. Differentiation of self, couple adjustment and family life cycle: A cross-sectional study. Am J Fam Ther. 2020; 48(4):299-316. [DOI:10.1080/01926187.2020.1736689] 
14. Noori J, Nejat H, Nameni E, Fariborzi E. Comparison of the effectiveness of the treatment of a monotheistic integrated and the objective relationship on self-differentiation and marital intimacy. Am J Fam Ther. 2020; 48(1):70-86. [DOI:10.1080/01926187.2019.1679052] 
15. Bui MV, McInnes E, Ennis G, Foster K. Protocol for a mixed methods process evaluation of the promoting resilience in nurses (PRiN) trial. Int J Ment Health Nurs. 2022; 31(3):687-96. [DOI:10.1111/inm.12989] [PMID] 
16. Işık E, Özbiler Ş, Schweer-Collins ML, Rodríguez-González M. Differentiation of self predicts life satisfaction through marital adjustment. Am J Fam Ther. 2020; 48(3):235-49. [DOI:10.1080/01926187.2020.1732248] 
17. Lampis J, Cataudella S. Adult attachment and differentiation of self-constructs: A Possible dialogue? Contemp Fam Ther. 2019; 41(3):227-35. [DOI:10.1007/s10591-019-09489-7] 
18. Masten AS, Lucke CM, Nelson KM, Stallworthy IC. Resilience in development and psychopathology: Multisystem perspectives. Annu Rev Clin Psychol. 2021; 17:521-49. [DOI:10.1146/annurev-clinpsy-081219-120307] [PMID] 
19. Bartle-Haring S, Ferriby M, Day R. Couple differentiation: Mediator or moderator of depressive symptoms and relationship satisfaction? J Marital Fam Ther. 2019; 45(4):563-77. [DOI:10.1111/jmft.12326] [PMID] 
20. Peleg O, Messerschmidt-Grandi C. Differentiation of self and trait anxiety: A cross-cultural perspective. Int J Psychol. 2019; 54(6):816-27. [DOI:10.1002/ijop.12535] [PMID] 
21. Robins N. Of Love and loathing: Marital Life, Strife, and Intimacy in the Colonial Andes, 1750-1825. Am Hist Rev. 2021; 122(1):221-2. [DOI:10.2307/j.ctt1d9nhx8]