Knowledge and perception of cardiovascular disease risk among patients with rheumatoid arthritis

Patients with rheumatoid arthritis are at increased risk for cardiovascular disease. The prerequisites for reducing the risk of cardiovascular disease are adequate levels of knowledge and being aware of the risk. In this study, the levels of knowledge about cardiovascular disease among patients with rheumatoid arthritis and the perception were evaluated in relation to their actual 10-year risk of cardiovascular disease. This cross-sectional study of 200 patients with rheumatoid arthritis was conducted in a university-affiliated hospital in South Korea. The patients’ actual risk of cardiovascular disease was estimated using the Framingham Risk Score. The most common risk factor was physical inactivity, with 77% of the patients not engaging in regular exercise. The patients lacked knowledge about the effects of physical inactivity and anti-inflammatory medication on the development of cardiovascular disease. Misperceptions about the risk of cardiovascular disease were common, i.e., 19.5% of the patients underestimated their risk and 41% overestimated. Hypertension, diabetes, obesity, and smoking were the most prevalent among the patients who underestimated their risk, and these same patients had the lowest level of knowledge about cardiovascular disease. This study demonstrated the rheumatoid arthritis patients’ lack of knowledge about the effects of physical inactivity and anti-inflammatory medications on the development of cardiovascular disease, and their misperception of cardiovascular risk was common. As a preventive measure, educational programs about cardiovascular disease should be tailored specifically for patients with rheumatoid arthritis, and behavioral interventions, including routine exercise, should be made available at the time of diagnosis.


Introduction
Rheumatoid arthritis (RA) is a chronic, progressive, and disabling autoimmune disease that affects about 2% of the Korean population [1]. Patients with RA have significantly increased risk of cardiovascular disease (CVD) than general population [2]. They have significantly higher risk of myocardial infarction and sudden cardiac death than those without RA of the PLOS ONE | https://doi.org/10.1371/journal.pone.0176291 April 24, 2017 1 / 12 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 encouraged to ask for assistance, if needed. A small gift with a value of $10 was given to the respondents. Of 202 patients who completed the survey, two had missing data on several study variables, and therefore those two were excluded, yielding a final sample of 200 patients with RA in the study. Data were collected in December 2015.
be equivalent to CVD for risk classification purposes, so they were classified into the high risk group. These steps allowed us to classify the subjects into low (no CVD risk factors), moderate (at least one CVD risk factor and an FRS < 10%), and high risk for developing CVD (at least one CVD factor and an FRS ! 10% or those with diagnosed diabetes).

Perceived CVD risk
One question concerning the likelihood of having CVD in the next 10 years was used to measure the participants' perceived risk for CVD. Possible response categories were very low, low, moderate, high, or very high; 'very low' and 'low' responses were combined as 'low,' whereas 'very high' and 'high' responses were combined as 'high' so they could be compared with the actual CVD risk in this study. Disease features. Disease features were measured with the Multidimensional Health Assessment Questionnaire (MDHAQ) [27], which includes assessments of physical function, psychological distress, perceived general health, and severity of symptoms of RA, such as pain and fatigue. Higher scores indicate worse levels of physical function, psychological distress, and general health status and more severe levels of pain and fatigue. The MDHAQ has been validated for Korean Patients with RA [28]. RA-related laboratory test results, i.e., C-reactive protein (CRP), RF, and anti-CCP antibody, were obtained from the medical charts.

Statistical analyses
Statistical analysis was done using SPSS 22 (SPSS statistics IBM Corp. Armonk, NY, USA). Characteristics of the subjects and their CVD risk factors were presented with descriptive statistics. The level of overall CVD knowledge was summarized with mean and median values. The rates at which the subjects answered each knowledge question correctly were presented as percentages. Perceived and actual CVD risks were compared with cross-tabulations and the level of agreement between them was presented with a kappa statistic. Based on the cross-tabulation, subjects were placed into one of three categories, i.e., correspondence (perceived CVD risk agrees with the actual CVD risk), underestimation (perceived themselves to have lower CVD risk than the actual risk), or overestimation (perceived themselves to have higher CVD risk than the actual risk). A series of one way ANOVA and χ 2 -tests (or Fisher's exact test, when appropriate) were performed to determine any differences in the characteristics of the subjects in the three groups and their CVD risk factors on the agreement between perceived and actual CVD risk. The level of significance was set at 0.05.

Results
The characteristics of the subjects are presented in Table 1. Most were women (90.5%), and the mean age was 52.6 (± 7.9). The average age at diagnosis of RA in these subjects was 46.8 (± 8.9), and the average duration of the disease was 6.8 (± 5.3) years. The physical functional score was 0.95 out of 10 on average, meaning that the subjects were able to perform most of their daily physical tasks without difficulty. The mean scores for the pain and fatigue related to RA were 3.62 (±2.62) and 4.79 (±2.71) out of 10, respectively.
The most common CVD risk factor found in this sample was physical inactivity, with 77% not engaging in moderate physical activity three or more times per week. Forty-three percent of subjects were categorized as being overweight or obese. Among the subjects, 39% had hypertension, and about 25% were taking anti-hypertensive medications. The ratio of TC/ HDL-C was 3.12 on average, and 16.5% were receiving lipid-lowering therapy. Diabetes was present in 7%.
The level of CVD knowledge is summarized in Table 2. The average overall knowledge score was 9.93 (±1.77) out of 13. Most were unaware of the effects of exercise (question #6) and anti-inflammatory medications (question #12) on the development of CVD; however, the relationships between blood pressure, lipids, and CVD were well known. The subjects in this study were less aware of the correct answers to questions 6, 9, and 10 than the subjects in John et al.'s study [24].
Cross-tabulation of actual CVD risk and perceived CVD risk is presented in Table 3. Overall, 39.5% of subjects correctly perceived their CVD risk. However, 60.5% misjudged their risk, with 19.5% underestimating their CVD risk and 41% overestimating it. The agreement between perceived and actual risk was low with the kappa statistic of 0.16.  BMI: body mass index; Physical inactivity refers to physical activity less than 3 times/week; CVD: cardiovascular disease; CVD refers to self-reported diagnosed heart attack, angina pectoris or stroke. Further stratification of the cross-tabulation by subjects' characteristics is presented in Table 4. Those who underestimated their CVD risk were more likely to be men, older, and diagnosed with RA at a later age. They also lacked knowledge about CVD, and the prevalence of hypertension, diabetes, obesity, and smoking was greater than in the other groups. Those who were experiencing severe symptoms of RA, such as morning stiffness and fatigue, overestimated their risk for developing CVD in the future.

Discussion
Patients with RA are twice as likely to develop CVD as those without RA [2]. Compared to the general population of Korean women [29], the prevalence of traditional CVD risk factors, such as hypertension and diabetes, was high in this study's sample, as was the proportion of those at increased risk of CVD. In this study, 12% of the subjects with RA were categorized as having high risk for CVD, and 60% and 28% were categorized as having moderate risk and low risk, respectively. In a study using a representative sample of Korean women nationwide, 7.9% had high risk for CVD, 20.5% had moderate risk, and 71.6% had low risk [29]. Even though the average age of the subjects was about five years older than those in Boo and Froelicher's study [29] and about 10% of the people in the study were men, the excessive risk of CVD that was found in this study may be partially attributable to RA. Risk reduction through better control of modifiable CVD risk factors and therapeutic changes in lifestyle are critically important for preventing CVD in this group. Levels of CVD knowledge and an accurate risk perception affect people's willingness to change to healthy lifestyles. In this study, we examined the knowledge and risk perception of CVD in patients with RA in Korea to get some insight in designing evidence based interventions to reduce their increased risk.
In this study, subjects were generally well aware of traditional CVD risk factors. Majority were identified hypertension (91.5%), dyslipidemia (91.5%), smoking (90.5%) and diabetes (83.5%) as CVD risk factors. Even though the differences in measures make it hard to simply make comparisons of levels of CVD knowledge to those of general Koreans, it seems like that the subjects of this study are more knowledgeable about traditional CVD risk factors than previously reported. In a study of random sample of 1,304 Korean women (mean age of 50.24), 77.1% and 38.1% identified hypertension and diabetes as risk factors for CVD, respectively [30]. A study of Koreans aged 60 years or older reported that 78.4% and 47.1% were aware the effects of hypertension and diabetes on the development of CVD, respectively [31]. The overall average score of CVD knowledge in our subjects was 9.93 (± 1.76) out of 13. Among 13 items, Korean patients with RA got higher rates of correct answers in 10 items than U.S. patients [24]. Although it is difficult to compare scores of patients across different studies, the knowledge scores show that the current participants had a higher level of knowledge about CVD than those in John et al.'s study [24]. This may be related to the differences in their demographic characteristics. Our subjects were about 12 years younger and had higher education levels than those in John et al.'s study [24]. The three items that had lower correct rates than the subjects in John et al.'s study [24] were items 6, 9, and 10, i.e., physical activity, weight loss, and smoking cessation. Especially for item 6, the percentage of subjects who answered correctly was the lowest, with about 65% of the subjects indicating that only working out in the gym or in an exercise class would lower their risk for CVD. This is a significant concern, because most of the subjects in this study were physically inactive despite no difficulties in carrying out daily physical tasks. However, regular, even low intensity exercise is an integral part of long-term CVD risk reduction as well as better control of RA symptoms.
Although only 5% of subjects were current smokers, they were less aware that quitting smoking reduces their chance of getting heart disease. As shown in Table 2, subjects were well aware that smoking is a risk factor for CVD (question 2, 90.9%), but they were less aware of the beneficial effects of quitting smoking (question 10, 72.1%). Among smokers, only 40% were correctly answered for the question 10 (data not shown). Educational efforts should focus on the factors that affect the development of CVD and on ways to reduce the increased CVD risk, with the benefits of risk reduction that can be obtained by behavioral changes. In addition, the level of knowledge about RA-specific CVD risk generally was lower than that of generic CVD knowledge. An earlier study focused on the unmet educational needs concerning the CVD aspects of RA [32]. Lack of awareness and non-adherence to CVD prevention guidelines by healthcare providers could be a possible reason for RA patients' lack of knowledge about RA-specific CVD. Future research is warranted to evaluate healthcare providers' awareness of and adherence to CVD prevention guidelines. Tailored education programs regarding CVD risk specific to RA should be developed and delivered to patients with RA at the time of diagnosis so that appropriate risk reduction efforts can be implemented.
A mismatch between perceived and actual CVD risk seemed to be common in patients with RA (Table 3), and this was consistent with previous reports of other populations [23,33]. Approximately 20% of patients with RA underestimated their CVD risk, and 41% overestimated it. Since actual CVD risk does not necessarily match with an individual's risk perception, it is worth considering the specific characteristics of patients with RA who misperceive their CVD risk. Regrettably, hypertension, diabetes, obesity, and smoking were the most prevalent among the subjects who underestimated their CVD risk, and these same subjects had the lowest level of CVD knowledge (Table 4). Patients who were men, older, and had been diagnosed RA at an older age underestimated their CVD risk compared to their counterparts. This is consistent with previous studies in which women were reported to have a higher perceived CVD risk than men [33,34], and Korean men tend to have a more optimistic perception of their health than Korean women [34,35]. Additional research should be conducted to determine whether such gender-associated differences in risk perception among patients with RA affect health behaviors or CVD health outcomes. For the prevention of CVD, patients with RA need to be aware of their CVD risks and follow risk reduction strategies. An individual's CVD risk perception is related to various activities and affects personal decisions and healthy behaviors [36]. When patients with a high risk of CVD have optimistic perceptions of their CVD risk, they might overlook the importance of engaging in preventive activities. That is why we need to more focus on patients' underestimation of their CVD risk.
Patients with morning stiffness might have a poor perception of their health and overestimate their CVD risk. Patients with RA experience various general and muscular symptoms, such as functional limitations, pain, and fatigue. Although there is no statistical difference, they may perceive their general health to be too poor to correct, and their perception of their CVD risk might be overestimated. In the literature, it has been shown that an individual's perception of her or his general health [35] and level of knowledge [33] are related to the willingness to engage in healthy behaviors. According to the Health Belief Model, knowledge and perception of increased risk are necessary conditions for behavioral changes [37]. Generally, it is accepted that people who overestimate their actual CVD risk are more likely to engage in beneficial behaviors, such as smoking cessation, weight loss, physical activity, and medication adherence [18,38]. The patients with RA in this study who overestimated their CVD risk were non-smokers and had optimal weights. However, there was no statistical difference for physical inactivity.
CVD knowledge was a factor that influenced the underestimation of CVD risk in patients with RA. Adequate knowledge about CVD risk is an important prerequisite for making appropriate decisions concerning the prevention of CVD [33]. As stated earlier, to encourage behavioral changes, patients must be educated about CVD risk factors and the vulnerability of patients with RA to CVD. In this context, communication about the perception of CVD risk and actual risk factors between patients and healthcare providers is very important, and it is required to improve the accuracy of people's risk perception and health behaviors.
There are several limitations that should be acknowledged in order to appropriately interpret the results of this study. First, we used the FRS to estimate actual 10-year CVD risk because no culture specific tool was available. Notably, there is evidence that shows that the FRS underestimates the risk of CVD in women [39,40] and in patients with RA [41]. However, some studies have indicated that the FRS overestimates CVD risk in Asians [42,43]. When data are available, recalibration of the FRS should be considered to improve its accuracy in this population. Second, self-reported data for extra-articular diseases may affect the study's findings. The bias would be in the direction of underestimating the true risk. Third, most of the subjects in this study were women. This was, in part, because the incidence of RA is much higher in women. In previous multi-center studies of patients with RA in Korea, about 85-95% of the patients were women [44,45]. However, given that the incidence of CVD is higher in men than in pre-menopausal women, further studies should oversample men to have parity to enable gender-specific analyses. Nevertheless, this study identified specific CVD risk factors lacked knowledge and showed that there was a mismatch between perceived and actual CVD risk among patients with RA in Korea. By further clarifying the misperception into underestimation and overestimation and examining differences in characteristics of patients and their CVD knowledge according to risk perception, the findings of this study can be helpful in designing more appropriate educational materials for patients with RA and in directing cognitive behavioral interventions to reduce CVD risks.

Conclusions
This study demonstrated the subjects' lack of knowledge about the effects of physical inactivity and anti-inflammatory medications on the development of CVD. Patients with RA should know RA-specific risk factors and their increased risk for CVD. Tailored education programs regarding the cardiovascular risk that is specific to patients with RA should be developed and delivered to them at the time of diagnosis.
Supporting information S1 File. The data file of 200 patients with rheumatoid arthritis. (XLS) 8. Mosca