Introduction

Hemodialysis is a renal replacement therapy for end-stage renal disease (ESRD)1,2. Malnutrition is one of the most critical factors affecting morbidity and mortality in patients with ESRD, and hemodialysis treatment has been reported to cause significant imbalances in electrolytes and fluid levels, as well as the depletion of specific nutrients, particularly potassium, proteins, and amino acids3,4,5. Indeed, protein-energy wasting (PEW), which results from the depletion of protein and energy stores and has been associated with poor quality of life (QoL) and increased morbidity and mortality, is common among ESRD patients on hemodialysis6,7. Because of the catabolic nature of hemodialysis and the decreased dietary intake, patients have high requirements for protein and energy8,9. Maintaining adequate nutrition during hemodialysis is essential to prevent nutrient deficits10,11,12. A proper protein intake helps counterbalance the loss of electrolytes (while avoiding electrolyte excess), proteins, and amino acids4, limits complications, and improves patient outcomes13,14. Healthcare professionals can help mitigate the adverse consequences of malnutrition and enhance the overall well-being and outcomes of patients on hemodialysis. Still, even though healthcare providers have an essential role in providing nutritional counseling before and during hemodialysis, patients are responsible for their nutrition at home. Therefore, patient self-management, which requires adequate knowledge and attitude, is vital to maintaining proper nutritional intake during hemodialysis.

Proper KAP15,16,17,18, including caretaker management, is essential for adequate self-management during hemodialysis19. A previous study showed a poor KAP toward self-management among Iranian patients with type 2 diabetes on hemodialysis15. In India, most patients were unfamiliar with the renal diet and failed to adhere to it16. In South Africa, patients on hemodialysis had a poor KAP toward the renal diet and rarely consulted dietitians for their diet management17. In Singapore, patients with type 2 diabetes on hemodialysis were reported to have a high knowledge of self-management but poor actual practices18. Caregivers have a central role in the self-management of patients on hemodialysis, including preparing meals and managing medications and supplements20. In China, the KAP data on nutrition support during hemodialysis are lacking. Hence, this study aimed to explore the KAP of hemodialysis patients toward nutrition support and management.

Results

Demographic characteristics

Among a total of 464 initially collected questionnaires, there were 14 with the same option selected for all questions in KAP, 3 without informed consent forms, and 2 with illogical responses that were eventually excluded, resulting in 445 (95.91%) valid questionnaires finally included in the analysis. The highest frequencies were observed for the following variables: male (58.43%), age < 40 years (31.69%), BMI of 18.5–23.9 kg/m2 (56.40%), urban residence (75.28%), lower education (60.00%), unemployed (74.16%), income of < 5,000 CNY (50.34%), basic medical insurance for urban employees (60.45%), hypertensive kidney injury (28.09%), hemodialysis vintage of < 36 months (51.69%), and > 3 days of hemodialysis each week (88.99%) (Table 1).

Table 1 Characteristics of the participants.
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Knowledge, attitudes, and practice

The knowledge score was 11.44 ± 1.80 (possible range: 0–13). Higher knowledge scores were observed in participants who were ≤ 60 years old (P = 0.003), living in urban areas (P = 0.012), with higher education (P < 0.001), and employed (P = 0.039) (Table 1). Poor knowledge was observed for K8 (58.43%; “Foods such as whole grains, roughage, animal offal, shrimp and dairy products do not contain phosphorus”) and K12 (59.55%; “Body Mass Index (BMI) = Weight (kg) ÷ Height2 (m)”) (Table S1).

The mean attitude score was 30.29 ± 3.22 (possible range: 8–40). Higher attitude scores were observed in participants living in cities (P = 0.010) and with higher education (P = 0.008) (Table 1). Table S2 presents the distribution of the attitudes.

The mean practice score was 31.27 ± 5.67 (possible range: 8–40). Higher practice scores were observed in participants who were 40–50 years old (P = 0.038), with a BMI of 18.5–23.9 kg/m2 (P = 0.045), and living in urban areas (P = 0.021) (Table 1). Table S3 presents the distribution of the practice responses.

Correlation analysis

The knowledge scores were correlated with the attitude (r = 0.241, P < 0.001) and practice (r = 0.365, P < 0.001) scores, while the attitude scores were correlated with the practice scores (r = 0.311, P < 0.001) (Table 2).

Table 2 Correlation analysis of knowledge, attitude, and practice.
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Multivariable analysis

The multivariable logistic regression analysis showed that age > 60 years (OR = 0.487, 95% CI: 0.260–0.913, P = 0.025) and junior college or undergraduate education or above (OR = 2.606, 95% CI: 1.621–4.189, P < 0.001) were independently associated with adequate knowledge (Table 3). Knowledge (OR = 1.151, 95% CI: 1.024–1.294, P = 0.018) and female sex (OR = 0.632, 95% CI: 0.419–0.953, P = 0.029) were independently associated with positive attitudes (Table 4). Knowledge (OR = 1.404, 95% CI: 1.221–1.614, P < 0.001), attitude (OR = 1.146, 95% CI: 1.069–1.227, P < 0.001), age 51–60 (OR = 1.879, 95% CI: 1.093–3.229, P = 0.022), and BMI of 24.0–27.9 kg/m2 (OR = 0.434, 95% CI: 0.269–0.700, P = 0.001) were independently associated with proactive practice (Table 5). The evaluation indicators for multivariable logistic regression models are shown in the Tables S4–5.

Table 3 Multivariable analysis of knowledge.
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Table 4 Multivariable analysis of attitude.
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Table 5 Multivariable analysis of practice.
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Discussion

This study showed that the patients on hemodialysis had adequate knowledge, positive attitudes, and proactive practices toward nutritional support; however, there were several gaps in knowledge and misconceptions regarding proper nutritional self-management.

Men were over-represented in the present study, which is consistent with the higher frequency of renal replacement therapy in men than in women observed worldwide21,22. The knowledge, attitude, and practice scores were relatively high in the present study. They were higher than those reported in a study conducted in South Africa that identified poor knowledge in 49.4% of the participants, negative attitudes in 60.0%, and poor adherence to the renal diet in 61.4%17. Similar results were observed in Iran among patients with type 2 diabetes mellitus on hemodialysis15. A study in India showed that although most hemodialysis patients had excellent renal diet-related knowledge, most did not adhere to it16. A study in Fiji showed high knowledge, attitude, and practice levels in 61.8%, 63.6%, and 88.4% of their participants, respectively18.

In this study, most participants had good knowledge regarding the nutrients they needed to avoid or consume to enrich their diets, which is similar to studies in the United Kingdom23 and South Africa17. On the other hand, approximately half of the participants showed inadequate knowledge of the phosphorus content in specific foods, which is important since excess minerals can cause side effects23. At the same time, previous studies have shown that knowledge of proper nutrition is relatively low in the general population in China24,25,26. Hyperphosphatemia is one of the most common and severe complications of ESRD27; however, the participants in the present study showed good knowledge of potassium intake. Although the score for knowledge regarding adequate daily protein intake was > 70%, this aspect might require improvements.

This study found that three-fifths of the participants had a low education level, and higher education was independently associated with higher knowledge scores. Health literacy is well known to be associated with socioeconomic status27,28, so this could explain low health literacy. Older age was also independently associated with lower knowledge, as supported by a review highlighting older age as a risk factor for low health literacy29, which could also be related to the differences in the education older people received when they were young, the use of modern technologies, and interest in the outside world.

In the present study, most participants had good attitudes toward nutrition support during hemodialysis. The knowledge score was independently associated with the attitude scores, as supported by the KAP framework that proper knowledge helps cultivate positive attitudes30,31. Nevertheless, it has been suggested that patients with a poor attitude should receive nutrition education, irrespective of their knowledge level32. Indeed, 29–35% of the patients in the United States of America had a good knowledge of the renal diet but considered that the renal diet interferes with their life (i.e., negative attitudes)33. This was also observed in the present study, where 37.53% of the participants considered it hard to change their dietary habits (item A6), and 34.18% thought that the restrictions made them anxious and irritable (item A7). The female gender was also independently associated with lower attitude scores. A previous review showed that women generally had better attitudes toward the renal diet than males34. In fact, only one study showed that males were more likely to adhere to the diet35. The present study did not examine the causes of these differences, which would be an interesting avenue for future studies. Being overweight was associated with lower practice scores, which is possibly related to a lower willingness to change dietary habits. Excess weight is a well-known barrier to lifestyle changes36,37. The knowledge and attitudes scores were independently associated with the practice scores. These results are in line with the KAP framework, stating that knowledge is the basis for practice while attitude is the force driving practice30,31. Age 51–60 was independently associated with higher practice, which could be related to a will to prolong life and quality of life.

The present study suggested that the KAP scores were correlated with each other, the knowledge scores were independently associated with the attitude and practice scores, and the attitude scores were independently associated with the practice scores. An interventional study reported that a KAP-based educational intervention improved patients’ knowledge of hemodialysis38. Hence, improving knowledge should theoretically also improve attitudes and practice; however, this is somewhat debatable since some studies have found a relationship between knowing dietary restrictions and support, while others have not32,33,39. Nonetheless, accurate nutrition knowledge may be fundamental when patients are ready to make dietary changes23.

The present study has several limitations. Although it was performed at a high-volume hemodialysis center, this was a single-center study with a limited number of participants from a single city, limiting the generalizability of the results. Local investigators developed the questionnaire according to the local reality, which further limits the external validity of the questionnaire. In addition, there were no questions on other aspects of CKD management, such as drugs. KAP studies provide insight into a given population at a precise time. This was a cross-sectional study, and as such, it could not identify the risk factors for poor adherence, but the results could serve as a baseline to evaluate the effect of future education interventions30,31. In addition, all KAP surveys are at risk of social desirability bias, as the participants can be tempted to answer what is socially expected instead of what is real40,41.

Conclusion

Patients on hemodialysis showed adequate knowledge, positive attitudes, and proactive practices; however, there were several gaps in knowledge and misconceptions regarding proper nutritional self-management. Older age was associated with poorer knowledge, while higher education was associated with a higher level of knowledge. Better knowledge was associated with more positive attitudes, while female gender was associated with more negative attitudes. A higher level of knowledge and attitude and age 51–60 were associated with better practice, while a higher BMI was associated with poorer practice. It is crucial to address these gaps and misconceptions through carefully designed and effectively implemented education to provide comprehensive guidance on optimal nutrition and self-management strategies.

Methods

Study design and participants

This cross-sectional study enrolled hemodialysis patients treated at the West China Hospital of Sichuan University between January and March 2023. The inclusion criteria were: age ≥ 18 years (i.e., the age of majority in China), regular outpatient maintenance hemodialysis (MHD) treatment duration of ≥ 3 months, clear consciousness, ability to read and understand Chinese, and providing informed consent. The exclusion criteria were critical condition, physical mobility impairment, emergency hemodialysis, or inability to complete the questionnaire due to severe visual and hearing dysfunction.

This study was approved by the Biomedical Ethics Committee of West China Hospital, Sichuan University [2021–1194], and all participants provided written informed consent. All methods were performed following the relevant guidelines and regulations.

Questionnaire

A self-administered questionnaire was developed based on the previous literature42,43. The questionnaire was pretested on 52 participants, revealing a Cronbach’s α of 0.770 and Kaiser–Meyer–Olkin (KMO) of 0.832, indicating good internal consistency. The pretest results were not included in the final analysis.

The final version of the questionnaire was in the Chinese language (a version translated into English was attached as an Appendix), and it contained four dimensions: demographic characteristics (11 items), knowledge dimension, attitude dimension, and practice dimension. The knowledge dimension consisted of 13 questions, where 1 point was assigned for the correct answer and 0 points for the wrong or unclear answer, with a final score ranging from 0 to 13 points. The attitude dimension included eight questions that were evaluated on a 5-point Likert scale, with the positive attitude questions being forward-assigned from strongly agree to strongly disagree on a scale of 5 points to 1 point and the negative attitude questions (items A5‒A7) being reverse-assigned, with scores ranging from 8 to 40 points. The practice dimension consisted of eight questions evaluated on a 5-point Likert scale, where 5 to 1 points were assigned from always to never, with a final score range of 8‒40 points. Adequate knowledge, positive attitude, and proactive practice were defined by a score > 70%44 of the maximum range of the total score for each dimension.

Questionnaire distribution and quality control

The questionnaires were administered to patients visiting the hospital through convenience sampling. Convenience sampling was used because the patients were enrolled when they presented at the hospital for treatments or consultation, and it was convenient for the personnel to enroll the patients without disturbing the clinical activities. It was also convenient for the patient to complete the questionnaire. No active prescreening or patient identification was performed. No active effort was made to contact a patient who was absent on a given day. Only their availability and that of the study staff were considered. During the investigation, the researchers avoided bothering patients during eating, treatment, and rest time. They explained the purpose, content, and significance of the study to the survey subjects and obtained informed consent from them. All patients participated voluntarily and had the right to withdraw at any time. The questionnaire was completed independently by the respondents. If there were any difficulties in understanding the questionnaire, the participants were instructed to ask the researchers who would explain all the uncertainties. All questionnaires were issued on the spot, recovered, and checked. The missing or wrong items were supplemented in a timely manner to ensure the accuracy, authenticity, and integrity of data. The electronic questionnaires were created using Sojump (https://www.wjx.cn/) and distributed to the study participants. A QR code for the electronic questionnaire was generated, and the participants could log in and fill in the questionnaire by scanning the QR code sent via WeChat. In order to ensure the quality and completeness of the questionnaire results, each IP address could only submit one questionnaire, and all items were made mandatory. The researcher assisted in answering the queries from the study participants and checked all questionnaires for completeness, internal consistency, and reasonableness. Questionnaires with any contradictory logic or incomplete responses were considered invalid.

Statistical analysis

SPSS 22.0 (IBM Corp., Armonk, NY, USA) was used for analysis. Continuous variables with a normal distribution were expressed as the mean ± standard deviation (SD) and were analyzed using Student’s t-test or one-way analysis of variance (ANOVA). Participants were divided into age groups as follows: < 40 years, including the children (0–19 years old) and the youth group (20–39 years old); 40–49 and 50–59 years, including the adult group grouped for every decade (40–59); ≥ 60 years, including older individuals (> 60 years old), according to the “Age-Based Grouping Criteria in Medicine45”. Categorical data were presented as n (%) and were analyzed using the chi-square test. Variables in univariable analysis with P < 0.0546 were included in multivariable logistics regression analysis. Multivariable logistic regression (enter method) was conducted to analyze the risk factors associated with KAP. Two-sided P < 0.05 was considered statistically significant46.