This cross-sectional study was conducted in two cleft lip and/or palate treatment centers in China. Both are provincial regional treatment centers affiliated with medical universities. The first is in northeastern China, and the second is in southwestern China. Data were collected between April 2019 and July 2020. The current research was approved by the Ethical Committee of China Medical University (NO. 2018-27).

Respondent inclusion criteria were as follows: (1) Fathers/Mothers of patients with CL/P under 18 years old; (2) agreement to participate in the survey; (3) the capability to understand and complete the questionnaire. The exclusion criteria were as follows: (1) the respondents had other care tasks; (2) the patients had other comorbid serious diseases. The study size was arrived at by using the following formula: n=Zα2σ2δ2 The parameters were α = 0.05, Zα = 1.96, σ = 15.39(arrived via the pre-test), and δ = 2; therefore, n = 1.96^2*15.39²/2² = 227.47. Considering that there were invalid questionnaires, the sample size was increased by 10~20%, and the final sample size was 251~273.

The whole process of the study was anonymous and voluntary for the parents. The investigators consisted of four nurses who were trained uniformly by the researcher. At the time of the patient's visit, informed consent was given to their parents. After agreeing to participate, one of the parents filled out a paper version of the questionnaire in a separate, undisturbed space in the hospital, so that the parents would not influence each other in completing the questionnaires. The investigators were responsible for providing explanations for questionnaire items without any inducement. Another trained investigator conducted quality control on the spot and then collected the questionnaires. Epidata software (version 3.1) was used for data entry and double-checking.

Demographic and clinical characteristics were collected via a general questionnaire. Demographic characteristics consisted of the ages of patients and fathers/mothers, the sex of patients, whether the patient was an only child, developmental status of patients, education level of fathers/mothers, job status of fathers/mothers, religious belief of fathers/mothers, monthly income, residence area, family structure, and medical payments. Clinical variables included patient's type of oral cleft and family history (Whether there is a cleft lip or palate in the family).

Statistical Package for Social Sciences (SPSS 22.0 for Windows) was used to conduct data analyses. Significance for all statistical tests was set at 0.05 (2-tailed). The normality and homogeneity of variances were first tested for each continuous variable. Independent sample T-tests and one-way ANOVA were used to describe distributions of resilience in categorical demographic and clinical variables among fathers and mothers. Pearson's r test was conducted to test the correlations among hope, perceived social support, optimism, parenting stress, coping and resilience. Hierarchical linear regression analyses were conducted to test the study hypotheses. The variables with P < 0.2 in one-way ANOVA/t-test were entered into step 1 of the hierarchical regression analysis as control variables in order to not overfit the regression models (53). Then, the independent variables (hope, perceived social support, optimism, parenting stress, and the coping of the parents) were also entered into step 2 of the hierarchical regression. Variables were entered in the regression analysis at P < 0.05 and removed from the model at P > 0.10. Multicollinearity diagnostic tests were carried out by the Tolerance and variance inflation factor (VIF). Data provided in the regression models included the standardization regression coefficient (β), R², adjusted R² (Adj. R²), R²-change and F value.

In the current study, 262 questionnaires were distributed. Among them, seven participants refused to attend the survey, seven questionnaires were considered invalid. The number of valid questionnaires was 248, yielding an effective response rate of 94.66%.

Among the 248 participants, 69 (27.8%) were fathers, and 179 (72.2%) were mothers. The mean age of the patients was 7.70 years (SD = 5.76, range 0.08–18). In terms of the clinical variables, among all the patients, 53 (21.4%) had cleft lip, 77 (31%) had cleft palate and 118 (47.6%) had both cleft lip with cleft palate. Only 13 (5.2%) patients had a family history of cleft lip and/or palate. The demographic and clinical characteristics and the level of resilience among fathers/mothers of patients with CL/P were described in Table 1.

Although there was no significant difference in the level of resilience between fathers and mothers of patients with CL/P, the resilience level of fathers was higher than that of mothers, which was were described in Table 2.

The results of the correlation analysis of hope, perceived social support, optimism, parenting stress, and coping with resilience among fathers of patients with CL/P are presented in Table 3. Resilience was positively associated with hope (r = 0.533, p < 0.001), perceived social support (r = 0.325, p < 0.01), optimism (r = 0.261, p < 0.01) and coping (r = 0.462, p < 0.001) and negatively correlated with parenting stress (r = −0.312, p < 0.01).

The results of the correlation analysis of hope, perceived social support, optimism, parenting stress, and coping with resilience among mothers of patients with CL/P are presented in Table 4. Resilience was positively associated with hope (r = 0.448, p < 0.001), perceived social support (r = 0.420, p < 0.01), optimism (r = 0.226, p < 0.01) and coping (r = 0.357, p < 0.001) and negatively correlated with parenting stress (r = −0.382, p < 0.001).

Hierarchical linear regression analysis was conducted to identify the influential factors of resilience among the fathers/mothers of patients with CL/P. Variables that were significantly associated with resilience in the univariate analyses, and variables related to the psychology of parents were included in the multiple regression analysis.

Among fathers, demographic variables (the age of patients, job status, income, residence, medical payments, and type of oral cleft), hope, perceived social support, optimism, parenting stress, and coping were included in the regression analysis. The results of the analysis are shown in Table 5. Hope (β = 0.400, P < 0.01), coping (β = 0.281, P < 0.05), job status, medical payments (β = −0.240, P < 0.05) were found to be associated with resilience among the fathers of patients with CL/P, and all four variables in the model could explain 42.8% of the variance in resilience.

Among mothers, demographic variables (the age of patients, education, and medical payments), hope, perceived social support, optimism, parenting stress, and coping were included in the regression analysis. The results of the analysis are shown in Table 6. Hope (β = 0.225, P < 0.05), perceived social support (β = 0.194, P < 0.05), the age of patients (β = 0.189, P < 0.05) were found to be associated with resilience among the mothers of patients with CL/P, and all four variables in the model could explain 27.6% of the variance in resilience.

The level of resilience in the study was similar to (54) or higher (55) than previous studies of caregivers of children with chronic diseases. Besides, the resilience level of fathers was higher than that of mothers, though there was no significant difference. The finding was significant due to the lack of information available in the literature about resilience in parents of patients with CL/P. This result is explainable. On one hand, resilience emphasizes that individuals can actively respond and adapt well in the face of negative events such as threats, adversity, or pressure (56–58), in which fathers have certain advantage over mothers. As parents accept and work hard on the disease gradually, their resilience level will become higher. On the other hand, CL/P is not a life-threatening disease but a disease with a promising cure. The patient's condition will improve as the treatment progresses. Therefore, in our clinical work, we should pay more special attention to the psychological status of parents of young patients.

At the same time, we noticed that more mothers (179, 72.2%) were recruited in the study than fathers (69, 27.8%). The result came as no surprise to us, because quite many studies have shown the similarly information, both in parents of patients with CL/P (24, 59) and families having a child with chronic conditions (60). This phenomenon resulted from the fact that mothers usually took more responsibilities on child caring in families in China, in comparison with fathers. What's more, more fathers were employed than mothers in this study, similar to other research (12, 61). Besides, mothers had higher levels of parental involvement behaviors than fathers (62).

In the current study, hope, coping, job status and medical payments were found to be associated with resilience among the fathers of patients with CL/P. Hope, perceived social support and the age of patients were found to be associated with resilience among the mothers of patients with CL/P.

According to the results of logistic regression analysis, hope was the only communal variable strongly associated with resilience among both fathers and mothers of patients with CL/P, which was similar to the results in previous studies on the resilience of caregivers of children with chronic diseases (63, 64). Hope has been confirmed to be related to almost all health outcomes (65). It is part of the psychological capitals of caregivers. Hope is an important resilience factor when caregivers cope with the care pressure of patients, which can help caregivers alleviate negative psychological distress. Lloyd's research found that as an influential factor of mental resilience, a low level of hope could predict the anxiety and depression level of parents of children with intellectual disabilities (34). In addition, hope is an important influencing factor in the development of caregivers' resilience. In a longitudinal study, hopefulness was found to be capable of predicting resilience among hereditary colorectal cancer patients (66). Therefore, enhancing the level of hope may become an important strategy to increase the level of resilience among both fathers and mothers of patients with CL/P in China.

In addition to hope, we found that coping was another positive psychological resource for the resilience among fathers of patients with CL/P. There were rare studies on resilience of fathers. Fortunately, this result was consistent with previous findings on the psychological conditions among caregivers and mothers of patients with CL/P (67, 68). Active coping strategies are the behaviors taken by caregivers under the condition of good psychological adjustment, and the implementation of active coping strategies, in turn, will help to improve the psychological condition of themselves. Then, a virtuous circle forms, and the growth of parents' psychological capital is prompted. Nadia Hasanzadeh's study on mothers of patients with CL/P confirmed this and further pointed out that positive coping strategies not only help improve the mother's psychological status but also benefit the mother's parent-child behavior (68). Therefore, active coping strategies should be valued, and we suggest that in clinical care, clinicians and nurses should help fathers of patients with CL/P develop active coping plans to adjust their psychological pressure and relieve negative emotions.

In this study, we also found that perceived social support made a positive contribution to the resilience of mothers of patients with CL/P. The positive effect of social support has been confirmed in many studies, both studies on the resilience of caregivers with chronic diseases (35, 69) and studies on psychological conditions of caregivers of patients with CL/P (12, 67, 70). Perceived social support is a part of the positive psychological capital of almost all patients and caregivers. People with higher levels of perceived social support have more resources they can use to care for the patients, which lightens the burden of care and psychological burden. The level of resilience and psychological status are naturally improved. However, it is worth noting the results of two qualitative studies (35, 36). Their findings showed that the support of family and friends was not always sufficient to promote the psychological resilience of caregivers, and the support function helped to enhance resilience only when it was considered to match the needs. Therefore, the specific role of perceived social support needs further study and discussion.

On the other hand, it is interesting to note that some of the demographic variables have been demonstrated specifically associated with the resilience of parents of patients with CL/P.

First, we found that job status and medical payments were of great significance for the resilience of the fathers. In the study, fathers with regular employee had the highest level of resilience than other status. Regular employee meant a stable income. Besides, fathers of patients with public welfare program had higher level of resilience than others. Having public welfare program could be interpreted as less financial pressure. In other words, these two variables related to the fathers' resilience suggests that the fathers bear more economic pressure in the treatment of children. This is in line with the role of fathers in most Chinese families.

Finally, it was not surprising to find that the age of patients was an important factor for the resilience of the mothers. This has been confirmed not only in the study of the resilience of caregivers of children with chronic diseases (71) but also in the study of the psychological conditions of caregivers of patients with CL/P (28). In the study, the age of patients was associated with resilience of the mothers, not the fathers, possibly for the primary caregivers for CL/P was often the mothers. The resilience of mothers increases with the age of patients. It is a good phenomenon, mainly because as the patient grows up and the treatment progresses, the mothers can take care of their children more easily. However, one problem that we cannot ignore is the patient's psychological and developmental problems. The improvement of clinical symptoms does not mean the complete end of the child's treatment. In clinical practice, we have also found that many parents of patients with CL/P pay too much attention to the improvement of their children's appearance and function while ignoring their children's performance in interpersonal communication, personality development and school achievement and attribute the patients' inadaptability in these aspects only to different personalities and characteristics. Previous studies have also found similar problems (72–74). In summary, although the burden of life care and medical care for parents is reduced as patients with CL/P grow up, we should still remind parents and provide parents with relevant professional services to promote the healthy growth of patients' psychology and society.

However, the current study results were partially inconsistent with our hypothesis in that optimism and parenting stress showed no significant relations neither with fathers nor mothers. Therefore, further research is still needed to explore the exact mechanism of the two variables.