Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by unknown etiology and significant joint damage. It globally affects approximately 460 individuals per 100,000 population (1), with a prevalence of 0.32–0.42% within the Chinese population (2). If RA is not adequately treated, it can lead to persistent synovitis and the erosion of articular cartilage and surrounding bone, resulting in reduced mobility, decreased quality of life, and complications including cardiovascular and other extra-articular issues (3, 4). In addition to these complications, RA is often associated with metabolic comorbidities such as diabetes. Studies have shown that patients with RA are at an increased risk of developing type 2 diabetes due to chronic inflammation and glucocorticoid use, which can impair insulin sensitivity and glycemic control. Managing these comorbidities requires a holistic approach, where diet plays a pivotal role not only in mitigating RA symptoms but also in controlling blood glucose levels in diabetic RA patients (5, 6).

Dietary management is essential in RA treatment, as specific foods can help reduce inflammation and improve patient outcomes (7). For instance, diets rich in anti-inflammatory components, such as omega-3 fatty acids, have been shown to alleviate RA symptoms, while unhealthy choices may worsen them (8). Understanding how RA patients approach dietary management is vital for effective care.

Management of RA involves a comprehensive approach that includes both pharmacologic and non-pharmacologic (9, 10). Pharmacologic treatments primarily consist of disease-modifying anti-rheumatic drugs (DMARDs), nonsteroidal anti-inflammatory drugs (NSAIDs), and glucocorticoids, which help manage the inflammation and pain associated with the disease (4). Complementarily, non-pharmacologic treatments such as patient education, physiotherapy, and nutritional therapy play critical roles in the overall management of RA (11).

The Knowledge-Attitude-Practice (KAP) model is a crucial framework in the healthcare domain, extensively used to assess the knowledge, attitudes, and practices of target populations (12). This model is founded on the premise that enhanced knowledge positively influences attitudes, which in turn, shape individual practices, a process integral to health literacy (13). The use of the KAP questionnaire alongside this model helps evaluate the demand and level of acceptance of health-related content (14).

Diet, as a key modifiable factor in chronic disease management, significantly impacts patient outcomes, with robust evidence supporting the benefits of dietary improvements (15). For patients with rheumatoid arthritis (RA), dietary choices are critical as they can influence symptoms significantly; certain foods, especially those rich in n-3 polyunsaturated fatty acids (PUFAs) from fish, have been shown to alleviate symptoms, while unhealthy options may exacerbate them. Additionally, evidence suggests that dietary management can play a crucial role in preventing and managing diabetes in RA patients, with anti-inflammatory and low-glycemic diets helping control both inflammation and blood sugar levels (16, 17).

Despite the established importance of diet in RA management, there is a notable gap in research focusing on the KAP regarding dietary management among these patients. While there have been studies examining KAP in patients with chronic conditions like diabetes, the specific area of dietary KAP in RA patients remains underexplored. By exploring how RA patients perceive and implement dietary recommendations, researchers can pinpoint knowledge gaps and barriers to effective management. This understanding is essential for creating targeted educational programs and interventions that enhance dietary habits, thereby improving the quality of life and health outcomes. Therefore, this study aims to assess the KAP regarding dietary management among patients with RA, addressing an underserved area of research with potential significant clinical implications.

Initially, this study collected a total of 507 questionnaires. Of these, one was excluded due to the respondent being underage (0.20%), and two were excluded due to incorrect age data (0.39%), resulting in 504 valid questionnaires. The validity rate was 99.41%. Among the respondents, 407 (80.75%) were female, with a mean age of 59.72 ± 12.36 years. A total of 306 participants (60.71%) reported a BMI within the range of 18.5–23.9 kg/m². Regarding socioeconomic status, 287 respondents (56.94%) reported an average monthly income of 2,000–5,000 yuan, and 210 (41.67%) had attained an elementary school level education or lower. Furthermore, 174 participants (34.52%) had been diagnosed with rheumatoid arthritis for less than 5 years. Morning stiffness of less than 15 min was reported by 314 respondents (62.30%), while 296 (58.73%) were in the remission phase of the disease, 140 (27.78%) presented with joint deformity, and 494 (98.02%) were currently receiving pharmacological treatment as their primary form of management. The mean scores for knowledge, attitude, and practice were 10.13 ± 3.58, 31.38 ± 2.38, and 4.46 ± 2.30, respectively. Variations in knowledge scores were significantly associated with average monthly income (p < 0.001), educational attainment (p = 0.028), duration of rheumatoid arthritis (p = 0.037), joint function classification (p = 0.002), disease stage (p = 0.001), and pain assessment (p = 0.002). Attitude scores varied significantly across variables such as average monthly income (p = 0.012), type of medical insurance (p = 0.020), morning stiffness (p = 0.003), joint function classification (p < 0.001), joint deformity (p < 0.001), pain assessment (p < 0.001), and history of surgical treatment (p = 0.003). Practice scores showed significant variation based on average monthly income (p < 0.001), past year residence (p < 0.001), education level (p < 0.001), and medical insurance type (p = 0.011) (Table 1).

The distribution of knowledge dimensions shown that the three questions with the highest number of participants choosing the “Not clear” option were “Although vegetables are rich in antioxidants, some such as potatoes, tomatoes, and eggplants contain glycoalkaloids that can increase intestinal permeability, potentially adversely affecting the relief of rheumatoid arthritis symptoms.” (K11) with 53.97%, “Assessment of weight and body mass is based on body mass index (BMI).” (K3) with 40.28%, and “Are you familiar with the anti-inflammatory diet?” (K10) with 18.25% (Table 2).

Responses to the attitudinal dimension showed that 37.10% disagreed that they would prefer to be treated with diet management (A3), 28.37% agreed that diet management would affect their quality of life (A4), and 21.83% agreed that diet management was too burdensome and changed habits, which was difficult for them (A6) (Table 3).

The distribution of practice dimensions shown that the three questions with the highest number of participants choosing the “No” option were “You primarily use olive oil for cooking.” (P1) with 92.06%, “You use 4 tablespoons or more of olive oil daily.” (P2) with 91.47%, and “You consume less than 1 tablespoon of butter or margarine or cream daily.” (P5) with 89.68% (Table 4).

Correlation analysis revealed significant relationships between knowledge and practice (r = 0.294, p < 0.001) as well as between attitude and practice (r = 0.178, p < 0.001) (Table 5).

A cutoff value representing the top 60% of scores for each dimension was used to classify the participants, with 465 (92.26%) falling below this threshold for knowledge, 26 (5.16%) for attitude, and 460 (91.27%) for practice (Supplementary Table S1). Multivariate logistic regression showed that with average monthly income (OR = 3.875, 95% CI: [1.19, 12.613], p = 0.025), had rheumatoid arthritis for 11–20 years (OR = 2.751, 95% CI: [1.015, 7.456], p = 0.047), level II joint function (OR = 3.147, 95% CI: [1.176, 8.423], p = 0.022), level IV joint function (OR = 34.712, 95% CI: [3.121, 386.072], p = 0.004), pain assessment score 1–3 (OR = 0.157, 95% CI: [0.042, 0.581], p = 0.006), and pain assessment score 4–10 (OR = 0.101, 95% CI: [0.013, 0.768], p = 0.027) were independently associated with knowledge (Table 6). Concurrently, knowledge score (OR = 1.155, 95% CI: [1.017, 1.311], p = 0.026), with urban employee basic medical insurance (OR = 5.402, 95% CI: [1.373, 21.251], p = 0.016), with new rural cooperative medical system (OR = 8.678, 95% CI: [1.934, 38.934], p = 0.005), level II joint function (OR = 0.163, 95% CI: [0.044, 0.610], p = 0.007), level IV joint function (OR = 0.017, 95% CI: [0.001, 0.217], p = 0.002), pain assessment score 1–3 (OR = 5.085, 95% CI: [1.056, 24.487], p = 0.043) were independently associated with attitude (Table 7). Moreover, knowledge score (OR = 1.165, 95% CI: [1.078, 1.259], p < 0.001) was independently associated with proactive practice (Table 8).

The residual connection method was adopted to modify the SEM model so as to achieve a good fit (CMIN/DF value: 3.853, RMSEA value: 0.075, IFI value: 0.811, TLI value: 0.785, and CFI value: 0.810) (Supplementary Table S2), the results showed that knowledge had direct effects on attitude (β = 0.291, p < 0.001) and practice (β = 0.188, p < 0.001). Meanwhile, attitude had a direct impact on practice (β = 0.081, p = 0.045) (Supplementary Table S3 and Figure 1).

The study highlights a significant discrepancy among patients with RA, demonstrating inadequate knowledge but relatively positive attitudes toward dietary management, which did not strongly translate into active practice. It is recommended that clinical programs for RA patients incorporate targeted educational interventions to enhance dietary management knowledge, aiming to bridge the gap between attitudes and actual practices to improve health outcomes.

This study underscores a significant discrepancy between the positive attitudes toward dietary management in RA patients and their relatively insufficient knowledge and suboptimal practices. This finding is consistent with other studies indicating that while patients may be receptive to managing their condition through diet, a lack of comprehensive knowledge often hinders effective implementation (21, 22).

Specific factors such as average monthly income and education level significantly impacted KAP scores. For instance, participants with higher incomes exhibited better knowledge and practices, a pattern also reflected in the regression analysis where higher income was associated with improved knowledge. This finding suggests that economic factors may influence access to resources or educational opportunities that can enhance self-management capabilities (23, 24). Similarly, educational attainment correlated with knowledge and practice outcomes, reinforcing the need for tailored educational interventions that consider the varied socioeconomic backgrounds of patients.

Interestingly, while variables such as joint function classification and pain assessment significantly affected knowledge and attitudes, they did not markedly influence practice outcomes. This could be due to a lag between changes in perception and the actual adoption of new behaviors, or it may reflect other unmeasured barriers to behavior change such as physical limitations or psychosocial factors (25, 26).

The correlation and multivariate logistic regression analyses, as well as SEM, suggest a complex interplay between knowledge, attitudes, and practices. Our findings indicate that better knowledge about RA directly enhances both attitudes and practices, supporting the notion that informed patients are more likely to adopt and maintain beneficial dietary habits (27, 28). These results were consistent with previous research that emphasizes the pivotal role of patient education in chronic disease management (29, 30).

The findings from the knowledge dimension reveal substantial gaps in the understanding of dietary management among RA patients. A significant portion of the cohort displayed limited awareness of the role of BMI in RA risk, the importance of omega-3 fatty acids, and the specifics of anti-inflammatory diets such as the Mediterranean diet. This lack of knowledge was particularly pronounced concerning the impact of certain vegetables like potatoes, tomatoes, and eggplants on intestinal permeability and RA symptoms. To address these deficiencies, healthcare providers should implement targeted educational programs that not only explain the importance of diet in managing RA but also clarify common misconceptions. Programs could include detailed patient brochures, interactive online platforms, and structured dietary counseling sessions that tailor content to individual knowledge gaps and cultural preferences (31, 32).

Attitudinal responses highlighted a general recognition of the importance of diet management in RA, yet there was notable reluctance regarding its practical application and potential impact on quality of life. Particularly, many patients viewed diet management as cumbersome and less preferable compared to pharmacological treatments. To enhance acceptance and willingness to engage in dietary management, it is crucial to foster a supportive environment that empowers patients. This could be achieved through regular motivational interviewing sessions that address personal barriers and benefits perceived by patients, as well as through the development of peer-led support groups that provide empathy and practical tips from shared experiences. Furthermore, incorporating mobile health technologies that track dietary intake and provide real-time feedback could improve patients’ engagement and adherence (7, 33).

Practical adherence to recommended dietary guidelines was low, particularly in the usage of olive oil, the consumption of fish, fruits, and legumes, as well as in the reduction of red meat intake. This poor adherence might be reflective of both a lack of conviction in the efficacy of dietary measures and the perceived difficulty in integrating these into daily life (34, 35). To promote better dietary practices among RA patients, practical and accessible interventions are needed. This could include working with dietitians to create personalized meal plans that accommodate individual preferences and limitations, offering cooking classes that focus on preparing anti-inflammatory meals, and establishing partnerships with local food services to provide discounts on healthful food options. Additionally, implementing community-based programs that emphasize the social aspect of eating could help normalize and reinforce dietary changes (36, 37).

This study has several limitations that warrant consideration. First, the cross-sectional design limits the ability to establish causal relationships between the knowledge, attitudes, and practices regarding dietary management and rheumatoid arthritis outcomes. Second, the lack of a control group, as suggested, limits the ability to directly compare RA patients with a healthy population. Future studies should incorporate a quasi-experimental design to address this gap. In addition, the data were collected from a single institution, which may restrict the generalizability of the findings to broader populations with diverse healthcare settings and cultural backgrounds. Lastly, self-reported measures were used to assess dietary practices, which might introduce response biases and may not accurately reflect actual dietary behaviors.

In conclusion, this study indicates that patients with RA demonstrate a discrepancy between a positive attitude toward dietary management and both insufficient knowledge and suboptimal practices. Significant predictors of better knowledge and attitudes include socioeconomic status, duration of RA, joint function, and type of medical insurance, which also influence dietary practices. These findings highlight the need for healthcare providers to integrate more robust dietary education into patient care. By offering clearer guidance on anti-inflammatory diets and providing continuous support, clinicians can help patients better manage RA symptoms, ultimately leading to improved treatment outcomes. Adjusting care plans to include routine dietary counseling may enhance the overall effectiveness of RA management.