The global aging population and the increase in chronic diseases have made end-stage renal disease a significant health issue, following hypertension and diabetes. While maintenance hemodialysis prolongs survival, it also brings about complications and psychological stress. Depression is prevalent among elderly dialysis patients, severely impacting their quality of life, interfering with dialysis adequacy, and increasing the risk of readmission and mortality. In our study, the incidence of depression among elderly MHD patients in the modeling group was 38.2%, while the verification group showed a rate of 37.4%. The overall incidence of depression in the sample was 38.1%, which is consistent with the findings of Zou Y (36.29%) [20], indicating that depression is a common issue in elderly MHD patients. This suggests that healthcare professionals should prioritize the assessment of depression in elderly MHD patients, enabling early detection and targeted interventions to alleviate depressive symptoms and improve prognosis.
However, due to differences in study populations and environments, existing research shows varying depression rates among elderly MHD patients. For instance, studies by Sevinc M [21] and Meng Y [22] reported rates of 42.7% and 55.1%, respectively. These discrepancies may arise from variations in sample size, geographic location, healthcare standards, and assessment tools. Additionally, the multifactorial nature of depression—including socio-demographic, psychological, disease-related, and nutritional factors—contributes to inconsistencies in reported rates. Despite these differences, there is consensus that the depression rate among elderly MHD patients is significantly higher than that of elderly community members and other patient populations, underscoring the urgency of addressing this issue. Therefore, when assessing elderly MHD patients, it is crucial to consider various factors—socio-demographic data, psychological aspects, disease-related issues, and nutritional status—to ensure accurate diagnosis and prompt intervention.
This study successfully identified independent risk factors for depression in elderly MHD patients through logistic regression analysis. The factors included education level, frailty, cognitive impairment, visual impairment, malnutrition, social support, and activities of daily living, leading to the development of a nomogram risk prediction model. Internal validation results indicated an area under the ROC curve (AUC) of 0.836 (95% CI: 0.809, 0.864), with a sensitivity of 0.610 and specificity of 0.871. External validation revealed an AUC of 0.806 (95% CI: 0.748, 0.866), demonstrating the model's strong discrimination and predictive performance. Additionally, both the internal and external validation H-L goodness-of-fit tests yielded results (p > 0.05), and calibration curves closely aligned with the ideal line, indicating good consistency of the model.A cutoff value of 0.336 was established, allowing classification of subjects into high-risk and low-risk groups, thereby providing robust support for clinical decision-making. The DCA and net benefit curves further highlighted the model's potential in optimizing patient management and resource allocation. This approach offers individualized and evidence-based depression risk estimates for elderly MHD patients, assisting clinicians in accurately identifying high-risk individuals and tailoring targeted interventions to reduce the risk of depression, ultimately improving patients' overall health and quality of life.
The results of this study indicate that educational level significantly impacts the occurrence of depression in elderly MHD patients, with an odds ratio (OR) of 0.625. This suggests that patients with a high school or vocational education or above are generally less likely to experience depression compared to those with a middle school education or lower, which is consistent with findings from Muthukumaran [23] and Ye W [24]. Patients with higher education levels tend to have better acceptance and understanding of disease diagnosis, treatment knowledge, and health decision-making, allowing them to cope more effectively with challenges during treatment and thereby reducing negative emotions. Additionally, these patients are more likely to possess self-care awareness and actively seek medical assistance, facilitating access to quality healthcare resources and information. They also demonstrate greater adaptability to life changes and social role transitions, which aids their adjustment to the hospital environment and lowers the incidence of depression. Conversely, elderly MHD patients with lower educational levels often have limited knowledge and understanding of their disease and hemodialysis, combined with a weaker ability to process complex information, leading to increased feelings of fear and anxiety, thereby elevating the risk of depression [25]. Consequently, in clinical practice, healthcare professionals should implement more detailed individualized care measures for these patients, enhancing their understanding of their condition through effective communication and guidance, and encouraging a positive mindset towards treatment and recovery.
The findings of this study reveal a significant correlation between visual impairment and the incidence of depression in elderly patients undergoing MHD. Specifically, visual impairment has been identified as an independent risk factor for depression in this population, aligning with the conclusions of Bossola [26]. Vision is a crucial sensory system for conducting normal daily activities, with approximately 80% of human information acquired visually [27]. As individuals age, visual decline becomes more pronounced, particularly among MHD patients with diabetic nephropathy, where retinal complications may exacerbate vision deterioration. Visual impairment not only hinders the daily functioning of elderly individuals but also limits their capacity to engage in work and maintain social relationships, significantly impacting both their mental and physical health as well as their overall quality of life. A meta-analysis indicates that the prevalence of depression among elderly patients with visual impairment is considerably higher than that in the general elderly population [28]. Healthcare professionals should prioritize timely vision screening and treatment for this high-risk group, integrating visual training with daily living skills and mobility exercises to address challenges related to visual impairment. Additionally, timely psychological interventions are essential for supporting mental well-being and preventing depression.
Cognitive function levels in patients are considered important predictors of depressive symptoms. In this study, cognitive impairment was identified as an independent risk factor for depression in elderly patients undergoing MHD. Elderly MHD patients with cognitive impairment have a 2.766-fold increased risk of developing depression compared to those without cognitive impairment, consistent with the findings of Feng J [29] and Jung S [30]. The prevalence of cognitive dysfunction among elderly hemodialysis patients is reported to be between 30% and 60% [31, 32]. The relationship between cognitive function and depression remains controversial, with the underlying mechanisms unclear. Some studies suggest that cognitive impairment may not be an independent risk factor, while others indicate a close association between the two [33]. Given the context of elderly MHD patients, medical practice should involve a comprehensive assessment of cognitive function and depression, exploring their interactions and shared influencing factors. A comprehensive intervention program should be developed, incorporating strategies for cognitive function enhancement and depression management to promote healthy aging.
Malnutrition has been identified as an independent risk factor for depression in elderly MHD patients. Previous research has indicated a close relationship between depression and malnutrition in this population, with a malnutrition prevalence rate as high as 52% [34]. This may be attributed to elderly individuals often experiencing insufficient nutritional intake due to tooth loss and oral degeneration, which increases the risk of malnutrition, leading to issues such as hypotension and hypoglycemia, thus affecting dialysis efficacy and resulting in loss of treatment confidence, negative emotions, and ultimately depression. Moreover, long-term dialysis treatment can result in the accumulation of middle-molecule toxins in the body, causing metabolic disorders and acid-base imbalances, which impair central nervous system function and may lead to anxiety and depression [35].
As age increases, frailty emerges as another significant issue facing elderly MHD patients and should also be recognized as a notable risk factor for depression. In this study, frailty was identified as a risk factor for depression in elderly MHD patients (OR = 2.475), consistent with the findings of Yuan H [36]. Frailty reflects a decline in physiological reserve and abnormal multi-system regulation, serving as an independent predictor of falls, disability, and mortality in older adults [37, 38]. While MHD can alleviate uremic symptoms and prolong patient life, long-term dialysis may also lead to metabolic disturbances, toxin accumulation, and physiological decline, which exacerbate the risk of frailty. Additionally, with advancing age, muscle mass and strength in elderly MHD patients gradually decrease, with a frailty prevalence of 14–37% [39]. Patients with frailty often exhibit symptoms such as reduced walking speed, decreased physical activity, and increased fatigue, which are also clinical manifestations of depression. Given the high prevalence of frailty in the elderly MHD population and its impact on depression risk, it is particularly important to enhance the assessment and screening of frailty, as well as to provide appropriate intervention guidance. Interventions such as nutrition and exercise during the pre-frailty stage can effectively improve the frail state of patients and subsequently reduce the risk of depression.
The ability to perform activities of daily living is closely related to depression in elderly patients undergoing MHD. Good self-care abilities not only help reduce the incidence of depression, consistent with Liu YM's research [40], but also promote patients in maintaining a positive mental state and social functioning. However, elderly MHD patients with diminished self-care abilities often experience a decline in independence due to prolonged illness, leading to increased dependency and a higher likelihood of negative emotions, significantly elevating the risk of depression. Additionally, a decline in daily functioning reduces social activities, exacerbating feelings of loneliness and irritability, which further deepens depressive states [41, 42]. In contrast, patients with better self-care abilities are more capable of realizing their self-worth, maintaining psychological health, and effectively alleviating depressive emotions.
Furthermore, this study found that social support is an independent predictor of depression in elderly MHD patients. Patients with low levels of social support have a higher risk of depression, which aligns with the findings of Sezer S [43] and Wang X [44]. Social support is crucial in maintaining the overall health of elderly MHD patients, as it not only enhances their confidence in social interactions but also helps them face life and illness with a more optimistic attitude, thereby preventing the onset of depressive feelings. However, due to the frequency of dialysis treatment and changes in body image, social participation among elderly MHD patients is limited, leading to reduced social functionality and decreased utilization of social support, which increases the risk of depression. Therefore, healthcare professionals need to enhance communication with patients, improve their social confidence, and foster a positive outlook on life. Hospitals can organize support group activities to provide psychological and social support. Additionally, the government and community should promote public volunteer services and recreational activities to increase opportunities for elderly individuals to interact, helping them shift their focus and better integrate into society, ultimately reducing the risk of depression.
Risk assessment is a primary measure for preventing the onset of depression. An ideal clinical prediction model should be both accurate and user-friendly. This study utilized multifactorial regression analysis to identify seven main risk factors affecting depression in elderly patients undergoing MHD and established a nomogram prediction model based on these key factors. This model transforms complex regression equations into intuitive and understandable graphics through visual analysis, enabling healthcare professionals to predict the probability of depression quickly and accurately in elderly MHD patients.
Based on the assessment results from the model, healthcare providers can precisely identify high-risk populations for depression and develop more effective, personalized treatment plans to reduce its occurrence. Furthermore, to promote the widespread use of the nomogram in clinical practice, this study also converted it into an easy-to-use web-based calculator. Healthcare professionals simply need to input the relevant predictive variable scores into the web calculator, and the system will automatically calculate the patient's risk probability for depression. The development of this web-based calculator not only simplifies the operational process and enhances prediction accuracy but also significantly improves the efficiency of healthcare professionals in screening and managing depression in elderly MHD patients.
This study has limitations: it uses a single-city sample, affecting generalizability; it’s cross-sectional and can't establish causality, necessitating prospective research for better understanding. Additionally, while high-sensitivity C-reactive protein and interleukin-6 were identified as potential risk factors, their exclusion due to regional differences underscores the need to include biological markers in future studies to improve prediction accuracy and treatment strategies for depression in elderly MHD patients.