Although hemodialysis can save a patient's life, it cannot continuously remove excess water and toxins from the patient's body and has certain limitations26, therefore, dietary and exercise evangelism needs to be strengthened and sodium intake restricted. Disease factors and lack of knowledge are common factors of malnutrition in hemodialysis patients 27, 28, and patients can better manage their daily behaviors only if they have the relevant knowledge, so mastering dialysis-related knowledge is the most basic and extremely important part. Routine health education used in clinical practice can also help hemodialysis patients to improve their knowledge level, while SDT-based health education, patients' knowledge level improvement is more significant, and the difference between the two groups is statistically significant (P < 0.05), which may be due to the routine care adopted by the medical staff to explain the routine mission focused on theoretical knowledge inculcation, while the patient is passive mastery of the relevant knowledge, initiative and autonomy is low, resulting in the Poor effect of health guidance29. The intervention group is more to make the patients actively participate in the learning process, fully inform the patients of the importance of mastering knowledge, mobilize the patients' enthusiasm for learning through group discussions and other modes, give the dialysis patients the right to actively choose the learning mode, and make them actively participate in the process of mastering knowledge related to the disease.
Self-management in MHD patients can help correct bad habits, as well as increase one's ability to monitor disease status, increase treatment compliance and subjective motivation, thereby reducing complications and improving quality of life. Behavior change comes from internal motivation, and a healthy lifestyle is easier to implement and maintain, so increasing patients' awareness of psychological need satisfaction and self-determined motivation plays an important role in improving self-management. The results of the study showed that the self-management score of the intervention group was higher than that of the control group, which is consistent with the results of the study by Yan Xiaoying et al30, and it is possible that as the level of patients' knowledge related to hemodialysis improves, the patients' confidence and ability to manage their own symptoms increases, which in turn improves the level of self-management. As patients' level of knowledge about hemodialysis increases, their confidence and ability to manage their symptoms increases, leading to improved self-management. In addition, this study enabled patients to face up to their illnesses and accept themselves by meeting their basic psychological needs and developing motivation for self-management31. Throughout the intervention process, patients were informed of the importance of self-management by means of videos, verbal emphasis, group and other discussions, provided with reasons to reduce controlling behaviors, and trained in the skills they lacked; existing problems were discussed and exchanged by means of listening and a self-management plan was jointly developed. Individual guided interviews, on the other hand, took a step-by-step approach, adjusting goals and corresponding plans in a timely manner according to the patient's implementation, enhancing the patient's competence, and promoting autonomous motivation through the fulfilment of needs. The patients' motivation for self-management was strengthened, helping them to move from passive acceptance of care to active self-management, and promoting the establishment of their health behaviors32, by guiding patients to master diet management knowledge and cooking skills, such as cutting ingredients before washing, green leafy vegetables immersed in water for more than 30 minutes to reduce potassium intake. The dietitian works with the patient to develop an individualized nutrition plan, using the phosphorus/protein ratio concept to adjust the diet33, limiting the intake of potassium, phosphorus and other elements ensures adequate nutrient intake.
Excessive fluid intake and poor dietary management are major influences on imbalanced weight control during the interdialytic period, and weight gain during the interdialytic period in patients with MHD leads to increased volume loading and a 2.1-fold increase in the risk of death34, 35. The better the self-management of MHD patients, the better the IDWG can control them, only when patients internalize their motivation and make choices autonomously can they develop health behaviors autonomously and adhere to them in the long term, and the autonomy process of motivation internalization needs to satisfy the three basic psychological needs of autonomy, competence, and belonging for patients to be able to change or maintain their health behaviors. In this study, patients were instructed on how to estimate the water content of food and how to manage fluids by using graduated water cups, which increased their interest and confidence in diet and fluid management. The results showed that IDWG in the intervention group was lower than that control group and baseline, which was basically similar to that reported by Wang Z. et al36. It is suggested that health education based on SDT reduces IDWG of MHD patients by improving self-management ability.
Anxiety and depression are the most common mood disorders in MHD patients, which can lead to complications such as fatigue and sleep disorders, affecting their quality of life and treatment results37. Due to the similarity of symptoms between mood disorders and uremia, early diagnosis is often not possible38, and timely prevention is needed to reduce the disease burden of patients39. The results of this study showed that after three months of intervention, the anxiety and depression scores of the intervention group were lower than control group and baseline, and the differences were statistically significant. This may be related to the following reasons, firstly, in the process of communicating with patients, so that patients feel that they are cared for and accepted by others this study provides support for patients from multiple dimensions such as family members and patients' friends, which meets the relational needs of patients; secondly, in routine care, patients seldom take the initiative to look for caregivers to ask questions during the dialysis period, and health education measures based on SDT can allow patients to experience more attention and support for autonomy, patients emotions can be released more; Finally, praise and encouragement for patients who successfully complete the goal, affirm the efforts made by patients, thus prompting patients to produce a positive psychology; the positive concept throughout the study to improve emotional control, more conducive to the gradual transformation of patients' negative emotions, and positively cope with the problems of life.
4. limitations
The study has several limitations. First of all, this is a three-month single-center study, and there may be some limitations in sample selection, which may not represent all patients receiving MHD. Secondly, the intervention time is short, which has certain limitations in promotion. It is suggested that future studies should extend the intervention time and conduct a multi-center large-sample study to further explore the application effect of this theory in health education.