Self-esteem mediates the relationship perceived stigma with self-efficacy for diabetes management in individuals with type 2 diabetes mellitus

Diabetes mellitus (DM) is a global health problem that threatens the entire world whose prevalence is increasing fast. According to the data of the International Diabetes Federation (IDF), there were 537 million people with diabetes in the world in 2021. It is estimated that this number will reach approximately 643 million in 2030 and 783 million in 2045.¹ Moreover, according to IDF, approximately 90% of diabetes cases consist of type-2 diabetes mellitus (T2DM), and one in every 11 people in the world have diabetes.¹

Diabetes is not only a disease that progresses with physical symptoms but also a disease that has psychiatric and psychosocial aspects.² Such individuals may also experience psychological problems due to pressure and stigmatization by people around them.³

Stigma is founded on cognitive, emotional, and behavioral reactions to individuals with some diseases due to the cognitive schemas and prejudices of society against some patient groups. Stigma may be at least as dangerous as the disease itself. The stigmatized person is attributed a characteristic that is not based on facts and is infamizing.⁴ This social stigma, in time, leads to the person’s development of stigmatizing attitudes towards self.⁵ Self-stigma affects the mental health of the individual and their feelings on healthy living negatively.⁵ If the fact that genetic and environmental factors playing a role in the development of T2DM is neglected, perceptions that this disease is only related to the person’s lifestyle emerge. In this case, diabetes is perceived as a situation that is under the control of the diagnosed person, and thus, patients may think that they have caused their diabetes diagnosis by themselves.⁶

Studies carried out with people with diabetes have revealed that patients experience serious levels of stigma regarding the disease.^3,7-10 In their study carried out with 12,000 Americans with type 1-2 diabetes, Liu et al⁷ reported high levels of perceived stigma in the people with diabetes. In another qualitative study carried out by Browne et al,⁹ people with T2DM shared their stigmatization experiences and described DM as a disease involving shame and blame. Such prejudiced and stigmatizing attitudes regarding the lifestyle that causes the disease affect disease-related self-management and the disease process negatively.⁹

Diabetes management requires treatment compliance and the person to make some behavioral changes in their daily life. In addition, studies have shown that stigma perceived by people with diabetes affects their DM management negatively.^5,11-14 Kato et al⁵ reported that internalized stigma had a negative effect on the self-management of people with T2DM. In another study by Kato et al¹³ a negative relationship was found between the self-stigma levels and self-care behaviors of people with T2DM. In the study carried out by Lin et al¹⁴ with 115 people with T2DM, the authors reported that the self-stigma perceptions of the patients affected their DM-related self-care behaviors negatively.

Self-esteem, which is one of the main elements of the concept of self, was defined as the person’s value, embracement, trust, and respect for themselves.¹⁵ It was reported that individuals with high levels of self-esteem had better compliance with self-care activities.¹⁶ A study showed that the stigma perceived by people with T2DM led to a reduction in their self-esteem and their self-efficacy in DM management.¹⁷

It is known that individuals with high self-esteem show better compliance with DM-related self-care activities. In addition to this, the perception of stigma in people with diabetes affects their self-management of DM negatively. It has been reported that there is a negative relationship between stigma and self-esteem, where self-esteem decreases as stigma increases. From this perspective, it is considered that the variable of self-esteem plays a role as a mediator variable in the relationship between the perceived stigma and DM-related self-efficacy people with diabetes. In other words, the effect of the stigma perceived by people with diabetes on their self-efficacy may change when self-esteem is included in this relationship. There are limited number of studies on this subject in the literature.

From this perspective, in this study, primarily it was aimed to investigate the predictive effects of self-esteem and stigma in individuals with T2DM on their perceived self-efficacy in the management of DM. The second purpose of this study was to examine the mediating effects of self-esteem in the relationship between the stigma perceived by people with T2DM and their perceived self-efficacy related to DM management.

Methods

This study was carried out with an analytic cross-sectional design. The study was carried out with 162 patients with T2DM who visited the Internal Medicine outpatient clinic, Bartin Public Hospital, Bartin, Turkey, between December 2020 and May 2021. The STROBE guidelines for cross-sectional studies were followed. The population of the study consisted of all patients diagnosed with T2DM who attended examinations within a year in the Internal Medicine outpatient clinics, Bartin Public Hospital, Bartin, Turkey. As the total number of cases within a year was not exactly known, a power analysis was carried out using the G^*Power, version 3.1.7 software. The effect size was obtained as a moderate effect size (f2=0.15) according to the multiple regression analysis reported by Cohen.¹⁸ It was calculated that the study should include at least 107 individuals to obtain a power of 95% with an effect size of 0.15 and a significance level of 5%. The study was completed with 162 patients. At the end of the study, the effect size was 0.5 (p=0.05).

Patients were selected with the convenience sampling method based on whether they met the following inclusion criteria: I) being diagnosed with T2DM; II) taking medication (such as oral antidiabetic and insulin therapy); and III) voluntarily agreeing to take part in the study. We excluded patients with a diagnosis of type 1 diabetes, gestational diabetes mellitus, younger than 18, having psychiatric illness, and not taking medication.

The data were collected through face-to-face interviews with diagnosed T2DM patients after they had been informed on the research process. Before the surveys were distributed by the researcher, the interviewee was informed regarding the purpose of the study, the inclusion/exclusion criteria for sampling, the research process, and the content of the surveys. All patients provided written informed consent for their participation before study entry.

Ethical approval to carry out the study was obtained from the Bartin University Ethics Committee (date: 12.07.2019, approval number: 2019/156), and permissions were obtained from the Provincial Health Directorate (date: 03.09.2019, No.: 78239813-799). Before carrying out this study, permission to use the scales was obtained from their original developers by e-mail. The patients were informed regarding the purpose of the study, its content and that the data would only be used for scientific purposes. Identifying information was not requested from the patients. The study was carried out according the principles of Helsinki Declaration.

Results

It was determined that 36.4% of the patients were at the ages of 41-50, and 57.4% were male. While 83.3% were married, 49.4% were primary school graduates. Almost half (46.9%) had been with diabetes for 1-5 years, and 40.7% had a history of DM in their first-degree relatives.

The vast majority (82.1%) stated that they had previously received diabetes education. More than half (54.9%) of those who had received diabetes education reported that they did not find the education they had received adequate.

In the sample, 83.3% were using oral antidiabetic medication for treating their DM. While 86.4% said they used their medication regularly, 52.5% stated that they did not follow a diabetic diet, and 52.5% reported that they did not regularly exercise (Table 1).

Correlations between the perceived stigma, self-esteem, and diabetes management self-efficacy levels of the patients were analyzed. According to the analysis results, there was a negative correlation between self-esteem and perceived stigma (r= -0.29, p<0.05). There was also a negative correlation between self-efficacy and perceived stigma (r= -0.25, p<0.05). Additionally, a positive correlation was identified between self-efficacy and self-esteem (r=0.25, p<0.05; Table 2).

In Model 1, regression analysis was carried out to determine the effect of self-esteem on self-efficacy in diabetes management, and the results are given in Table 3. According to the ANOVA results that tested the validity and significance in the regression analysis, the F value for self-esteem was calculated as 10.464 and the significance value was calculated as p=0.001 at the 5% significance level. The R² value of the independent variable, which is the level of explanation of the dependent variable, was calculated as 0.056. According to this result, 5.6% of the change in self-efficacy is explained by self-esteem. It was found that self esteem had a positive predictive effect on diabetes management self-efficacy (ß=0.875). A model study to determine the effect of self-esteem on self-efficacy in diabetes is significant as a whole (R²=0.056; F=10.464).

In Model 2, regression analysis was carried out to determine the effect of stigma on self-esteem, and the results are given in Table 3. According to the ANOVA results that tested the validity and significance in the regression analysis, the F value for stigmatization was calculated as 14.237 and the significance value was calculated as p=0.000 at the 5% significance level. The R² value of the independent variable was calculated as 0.057. According to this result, 5.7% of the change in self-esteem is explained by stigma. It was found that perceived stigma had a negative predictive effect on self-esteem (ß= -0.095). A model study to determine the effect of perceived stigma on self-esteem is significant as a whole (R²=0.057; F=14.237).

In Model 3, regression analysis was carried out to determine the effect of percived stigma on self-efficacy in diabetes, and the results are given in Table 3. According to the ANOVA results that tested the validity and significance in the regression analysis, the F value for stigmatization was calculated as 10.659 and the significance value was calculated as p=0.001 at the 5% significance level. The R² value of the independent variable was calculated as 0.057. According to this result, 5.7% of the change in self-efficacy is explained by perceived stigma. It was found that perceived stigma had a negative predictive effect on self-efficacy in diabetes (ß= -0.294). A model study to determine the effect of perceived stigma on self-efficacy in diabetes is significant as a whole (R²=0.057; F=10.659).

The R² value was calculated as 0.085 for Model 4, in which the stigma variable and the self-esteem variable were included in the model. According to this result, 8.5% of the change in self-efficacy in diabetes is explained by stigma and self-esteem (R²=0.085; F=8.473; Table 3).

In the process of adding variables to the regression model, the change caused by the self-esteem variable in R² was calculated using the Stepwise method. While it was calculated as R² change =0.62; F=10.659 when there was only stigma variable in the model, it was calculated as R² change=0.034; F=5.957 when self-esteem was added to the model. This change shows that when the self-esteem variable is included in the model, the explanatory power of the model changes by 3.4% (Table 3). Additionally, the negative predictive effect of stigma on self-efficacy decreases when self-esteem intervenes (ß= -0.230) According to these findings and the results of the Sobel test, it was determined that self-esteem was a partial mediator (partial moderator) (Z= -3.347; p<0.05). In other words, stigma affects self-efficacy in diabetes management both directly and through self-esteem.

Discussion

This study was carried out to investigate the mediating role of self-esteem in the relationship between the perceived stigma levels of people with T2DM and their self-efficacy regarding diabetes management. In this study, it was determined that as the self-esteem levels of the people with T2DM increased, their diabetes management self-efficacy levels also increased, thus showing that self-esteem predicted self-efficacy in a positive direction (ß=0.875; p<0.01). This result was consistent with similar study findings.^26,27

Mikaeili et al²⁶ determined that people with diabetes with high self-esteem levels had higher levels of self-efficacy related to diabetes self-management. Kenowitz et al²⁷ also found that people with diabetes with high self-esteem had better compliance with their insulin treatments and exercise schedules. Based on these results, it may be argued that self-esteem makes the adaptation of people with diabetes to self-care activities easier and increases their self-efficacy levels. To increase the self-esteem of patients, healthcare professionals and particularly health and diabetic educators should help the recognition and expression of emotions by having effective communication with them based on empathy, respect, confidence, and care. It may be helpful to focus on past achievements of the person with diabetes and to use the support of family members.

Another result of this study was that perceived stigma had a negative predictive effect on diabetes management self-efficacy (ß= -0.294). Accordingly, the stigma perceived by people with diabetes affects their self-efficacy in the management of DM negatively, and as the level of stigma perceived by patients increases, this leads their self-efficacy regarding their disease to decrease. This result supported the results of similar studies in the literature.^{5,11-14,22,28,29} Kato et al¹³ reported a strong negative predictive effect of self-stigma on the self-care behaviors of people with T2DM. Brazeau et al¹¹ stated that in diabetic young people, stigmatization was associated with lower self-efficacy levels, higher A1c levels, severe hypoglycemia, and reduced feelings of wellbeing. A study carried out on T2DM patients revealed that stigma was a significant predictor of the negative perception of insulin treatment.³⁰ In individuals with chronic diseases like DM, self-stigma may affect their diabetes self-management negatively by leading these individuals to evade treatment or reducing their treatment adherence. Additionally, it may prevent these individuals from acting in favor of their care by themselves. Increasing the self-care behaviors of a person with diabetes by itself is not sufficient. These individuals need to develop positive attitudes towards the disease and get the help that will reduce their self-stigmatization. Recently published guidelines for the treatment of diabetes emphasize the importance of accounting for the psychological statuses of patients while managing their diabetes, especially their potential to stigmatize themselves.³¹ While they are providing education for people with diabetes, healthcare professionals and particularly health and diabetic educators should keep stigma in their minds and plan the appropriate precautions. Healthcare professionals for education for people with diabetes should focus on not only the physical but also the psychological wellbeing of patients and encourage the diabetic individual, their friends and family members to ask questions on stigma and share their feelings. In clinical practice, there is a need for routine assessment and interventions regarding self-stigma in person with diabetes. In both clinical and social settings, regular health education for increasing psychological wellbeing through reducing self-stigma is recommended.

Perceived stigma in people with diabetes leads their self-efficacy on their disease to decrease and their self-esteem to decline. In a qualitative study carried out by in-depth interviews with diabetes people, Seo et al³² reported that people with diabetes had lower self-esteem than the healthy individuals and negative attitudes regarding themselves. Another study showed the negative predictive effect of stigma on self-esteem in people with diabetes.¹⁷ In the current study, a negative significant relationship was identified between self-esteem and perceived stigma. Moreover, as a result a regression analysis was carried out to determine the effect of percived stigma on self-efficacy, it was found that perceived stigma had a negative predictive effect on self-esteem.

One of the issues of curiosity in this study was whether or not self-esteem played a mediating role in the relationship between the perceived stigma and diabetes management self-efficacy levels of people with T2DM. While research on this topic is limited, existing studies have reported that stigma reduces the diabetes management self-efficacy levels of people with diabetes not only directly but also by lowering their self-esteem.^17,33,34 A previous study used a model to determine how self-stigma affected the self-care behaviors of people with diabetes regarding diabetes management, where both the direct effect of the variable and its effect mediated by self-esteem were investigated. The authors demonstrated that self-stigma affected the patient’s activation both directly and under the mediation of self-esteem.¹⁷ In a study carried out with 501 people with T2DM, Pedrero et al³⁴ investigated the mediating role of psychosocial variables in the relationship between perceived stigma and self-management behaviors in people with diabetes, and they reported that self-esteem had a mediating role in this relationship. In similarity to the results of other studies, in this study, it was determined that the effect of perceived stigma in the patients on their diabetes management self-efficacy decreased when the variable of self-esteem was added to the model. In other words, when self-esteem was added as the mediator variable, the effect of stigma on self-efficacy was reduced. According to these results, interventions that increase self-esteem and self-efficacy may reduce self-stigmatization in people with T2DM, and thus, increase patient’s activation for self-care. It was emphasized that interventions that aim to improve self-care behaviors among people with T2DM should continue to directly target stigma, in addition to targeting self-esteem and self-efficacy at the same time.¹⁷

In order to manage the self-care behaviors of patients for optimizing their treatment outcomes, healthcare professionals should firstly assess the self-stigma levels of people with T2DM. These professionals should also try to encourage patients who stigmatize themselves to develop a positive self-image and a positive sense of sensitivity regarding their disease. Previous studies have provided evidence that interventions towards reducing self-stigma in psychiatric patients are effective in developing their skills for coping with self-stigma, improving their readiness to change their problematic behaviors, raising their self-esteem, and in turn, making their treatment compliance easier.³⁵ Intervention programs designed for reducing self-stigmatization may also provide similar favorable effects among individuals diagnosed with T2DM, and they may improve treatment compliance by reducing self-stigma levels through patient’s education programs. It is seen that there is a need for more studies focusing on interventional efforts towards eliminating stigma for both patients and healthcare professionals in relation to people with T2DM. Specific and interventional studies that examine the effectiveness of methods focused on reducing self-stigma among people with T2DM and increase self-esteem and self-efficacy should be carried out.