Preferences and Adherence of People with Prediabetes for Disease Management and Treatment: A Systematic Review

Introduction

Impaired Fasting Glucose (IFG) is defined as a fasting blood glucose of 5.6 to 6.9 mmol/L. Impaired Glucose Tolerance (IGT) is defined as a fasting blood glucose of less than 5.6 mmol/L and a plasma glucose level of 7.8–11.0 mmol/L at 2 hours after OGTT or a glycated hemoglobin of 5.7%-6.4%. Prediabetes is the stage between normal glucose metabolism and diabetes mellitus and is primarily characterized by impaired fasting glucose, impaired glucose tolerance, or both.^1,2 Currently, the prevalence of prediabetes is rapidly increasing worldwide. The world map of diabetes published by IDF in 2021 shows that about 541 million people are in the stage of impaired glucose tolerance.³ The prediabetes pandemic will greatly affect the prevalence of diabetes and its complications, and has gradually become a major public health problem.

Currently, the diagnostic criteria for prediabetes are not yet uniform, but the associated risks, such as glucose metabolism disorders, lipid metabolism disorders, and cardiovascular and cerebrovascular risks, are well-established.⁴ Some studies have found that about 10% to 15% of people with prediabetes will develop to dominant diabetes each year without intervention, and up to 79% of people with prediabetes will eventually progress to diabetes.^5,6

Current interventions for prediabetes primarily consist of behavioral management and pharmacological interventions, specifically metformin,⁷ which poses a major challenge to patient compliance. With the development of evidence-based medicine, patient preferences and evaluations have become increasingly important, and healthcare professionals have also realized the importance of personalized treatment.⁸ They are increasingly incorporating patient perspectives into treatment decisions, recognizing that patients’ unique environments, goals, and values should be referenced along with clinical evidence.⁹ But patients’ preferences and values are diverse and may differ from medical guidelines. Therefore, identifying the preferences and expectations of the prediabetic population regarding screening and intervention methods is beneficial for clinicians in developing effective diagnostic and treatment plans. In this study, the evidence on prediabetes population preferences was systematically collected.

Methods

Eligibility Criteria

This study includes literature that meets the following criteria:1) The study population is people with prediabetes; 2) Research content relates to participants’ views, preferences, and expectations regarding the management and treatment of prediabetes; 3) The research content includes the factors that influence the treatment of people with prediabetes. The exclusion criteria are as follows: 1) Not related to views, preferences and expectations of people with prediabetes; 2) Letters, reviews, case reports, invent and posters.

Data Sources and Retrieval Strategies

Search for publications in 5 databases, PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Internet (CNKI). Search time from the establishment of the database to June 2023. Using PubMed as an example, we searched the PubMed database for mesh terms related to prediabetes and patient preferences and applied keyword searching in combination with title summarization to find more comprehensive literature. Key phrases such as “prediabetes” and “prediabetic states” were used in conjunction with terms like “patient preferences”, “patient compliance”, or “patient values”, among others. Table 1 shows the PubMed search strategy. When searched other databases, we adjusted the retrieval strategy accordingly.

Table 1 Search Strategy for PubMed

Data Extraction and Quality Evaluation

Two authors independently reviewed retrieved studies using inclusion and exclusion criteria, read the title and abstract for initial screening, and communicated with the corresponding author to clarify any discrepancies. The reviewers extracted the first author, publication date, research type, research design, sample size, statistical methods, and research findings. Two reviewers independently use Agency for Healthcare Research and Quality (AHRQ),¹⁰ and communicated with the corresponding author when encountered differences of opinion. The AHRQ scale is a commonly used observational study assessment tool. Research is rated by answering 11 questions with “Yes” (1 point), “No” (0 point), and “Uncertain” (0 point). It is divided into three levels: low quality 0–3 points, medium quality 4–7 points, and high quality 8–11 points. Figure 1 shows the systematic literature review process.

Figure 1 Flow diagram of the selection process.

Results

Characteristics of Included Studies

A total of 2017 articles were retrieved from the five databases. After deduplication and screening the titles and abstracts, 62 articles were selected for full-text retrieval. Finally, 18 articles were found that met the inclusion criteria. Research on preferences of people with prediabetes is mainly conducted in the United States (n=12), China (n=3), Poland (n=1), Canada (n=1), and Australia (n=1). Table 2 provides an overview of 18 studies, including study data, sample size, study design, study description, patient preferences or wishes.

Table 2 Characteristics of Included Studies and Summary of Results

The Preferences and Expectations for Medical Treatment

There are 6 studies on drug therapy preferences and expectations. After summarizing the results of six studies, it was concluded that people with prediabetes commonly exhibit psychological resistance to drug treatment such as metformin. When there are other treatment options, they usually do not take drug treatment as their first choice, which may be related to the fear of drug side effects and drug dependence. However, people with a family history of diabetes or a willingness to lose weight have a higher acceptance of metformin. Bandi et al created a decision support manual for people with prediabetes.¹¹ They found that Spanish speakers and people with low levels of education were more willing to accept externally given suggestions for disease management and showed higher acceptance of metformin use. Moin et al included 515 participants in their study. 121 (23.5%) of the participants were willing to take metformin. Acceptance was higher in those under 50 years of age than in those over 60 years of age. Participants indicated that they would be willing to take the drug if it could help with treatment, even if there were side effects.¹⁹ Participants in the O’Brien et al study were very grateful to receive knowledge about prediabetes and diabetes during the research interview. When they learned that treatment with metformin could be beneficial, they expressed more confidence in managing prediabetes. Participants indicated they would be willing to try metformin if they wanted to lose more weight.²⁰ Rhodes et al studied 70 adolescents with prediabetes and their families, and the results showed that adolescents with a family history of diabetes had a higher acceptance of oral medications and insulin.²¹ The study by Rony et al shows that participants prefer nonpharmacologic therapy and suggests that participants’ low medication adherence may be related to medication side effects, fear of medication dependence, and distrust of the health care system. People with prediabetes want to be respected by health care providers, especially the black community.²² Speaker et al found that women, young people, and people with high BMI paid more attention to prediabetes intervention, white people preferred metformin, and black people preferred MNT.²³

The Preferences and Expectations for Personal Behavior Management

Ten studies reported on participants’ attitudes toward personal behavior management. After summarizing the ten studies, it was found that people’ attitudes toward prediabetes intervention through exercise and lifestyle change were positive, mainly because the body and mind could benefit more. And by teaching external factors such as professionals and mobile apps, participants’ blood glucose control and behavioral adherence could be effectively improved.

Coles’ randomized parallel intervention suggested that male participants with prediabetes preferred weight loss training under the guidance of professionals and preferred animal protein diet. While women have better self-control and show higher compliance in diet without choice.¹³ Among the individuals who participated in Moin et al’s study, 70% stated that they were more inclined to accept ILI (intensive lifestyle intervention) than metformin, and the proportion of women choosing ILI was significantly higher than that of men, and the participants with high BMI were also more willing to accept ILI.¹⁹ Study participants by O’Brien et al indicated that they preferred ILI as their preferred treatment because they believed it was a natural treatment with fewer side effects and other benefits besides reducing the risk of diabetes.²⁰ Fisher et al have shown that mothers in general would take a more proactive and empowering role in family-centered diabetes self-management education (DSME).¹⁶ Holmes et al found that adolescents with prediabetes enjoy resistance training (RET) at home and effectively improve their insulin resistance under the guidance of professionals.¹⁷ Marcinkiewicz et al found that workers followed medical advice 100% of the time after the fasting blood glucose test was included in mandatory employee screening.¹⁸ Previous studies had shown that these data were merely 36% to 93%, which will be useful for screening prediabetes.²⁹ Taylor et al reported that respondents wanted to acquire knowledge about PA (physical activity) (75%) and were willing to participate in PA (96%). They were more interested in regular and varied moderate-intensity exercise, such as walking.²⁵ Valero Elizondo et al found that older participants (≥ 65 years) generally did not accept more than two lifestyle interventions, whereas women and low-income groups generally received the least external health management advice.²⁶ The study of AI et al confirmed that participants are willing to actively control their daily caloric intake. With the assistance of the mobile application, participants were capable of adhering to diet healthily, manage exercise, monitor blood glucose, and gain confidence in overcoming the disease.²⁷ Duan et al found that age and freelance work were independent factors that improved compliance in people with prediabetes. They also discovered that using pictures, videos, and other means to prompt participants through cell phones, the Internet, and other platforms was more effective in enhancing participant satisfaction.²⁸

Additional Perspectives on Preferences and Expectations

Chen et al utilized “self-efficacy” as the dependent variable in their study, conducting a logistic regression analysis on the prediabetes population. The results indicated that individuals with high self-efficacy were more likely to be urban residents, married, and inclined towards interpersonal communication. In addition, the researchers found that fewer than 12% of respondents used suggestions from healthcare professionals as a source of disease information. It was also discovered that 72% of participants preferred to obtain disease information through search engines and social media, particularly young people. Most respondents reported feeling more confident in managing their illnesses after participating in online health communities.¹² The women who participated in the study by Dyer et al preferred to share their thoughts and information about illness face-to-face with individuals of the same sex. The face-to-face form of sharing makes individuals feel less lonely, while sharing exclusively with women gives them more confidence in communicating with one another.¹⁴ According to the research findings of Epstein et al, training participants to learn episodic future thinking may help improve treatment adherence. This improvement may be attributed to participants placing greater emphasis on the long-term benefits of treatment.¹⁵ The study by Marcinkiewicz et al also suggests that people with prediabetes may avoid glycemic control for economic reasons, as they fear that the disease could result in job loss.¹⁸ From the study by Rhodes et al, 72% of adolescents and 100% of parents believe that controlling diabetes through diet alone, without complications, is the most ideal state for the future. In addition, most participants believe that end-stage renal disease is the most feared complication.²¹ Although participants in Strauss et al’s research are in the early stages of diabetes, most of them believe they have no symptoms of diabetes and that it will not have an impact on their lives.²⁴

Discussion

This systematic literature review includes 18 publications summarizing the preferences, values, and expectations of people with prediabetes regarding drug treatment and personal behavior management. As a precursor to diabetes, prediabetes is associated with an increased risk of developing diabetes, cardiovascular events, and mortality.³⁰ Given this chronic condition of prediabetes, it is crucial to understand the treatment preferences and expectations of people with prediabetes, as this could help clinicians weigh the advantages and disadvantages of various treatment regimens and assist clinicians to provide accurate individualized treatment for people with prediabetes, which would improve patients’ sense of involvement and compliance. Drug treatment is the most crucial aspect of intervention measures in early diabetes. However, it is evident that people with prediabetes tend to have a negative and wait-and-see approach when it comes to drug intervention, specifically with metformin. Although metformin has been associated with lactic acidosis, gastrointestinal discomfort, anorexia, and other adverse effects.^31,32 However, current evidence supports the efficacy of metformin in reducing blood glucose levels, improving insulin resistance, and promoting weight loss in the early treatment of diabetes.³³ It is therefore necessary for clinicians to consider methods to improve the acceptance of drug treatment.

Diet and exercise management must not be ignored in the treatment of prediabetes. Reducing carbohydrate intake, consuming low-glycemic index (GI) foods, having regular meals, and engaging in physical activity are effective measures that can prevent the worsening of the disease.³⁴ In this study, it was found that people with prediabetes are generally willing to manage their blood glucose levels through dietary changes and physical activity. This willingness stems from their own efforts to attain a sense of accomplishment. However, the current issue is that prediabetic individuals have a limited understanding of lifestyle changes. In addition, various groups may hold different perspectives and preferences regarding lifestyle changes, which can be influenced by factors such as age, gender, income, and so on. Therefore, healthcare providers need to develop personalized treatment plans for various groups. In addition to real-world interventions, the internal world of prediabetes people also deserves attention. According to this study, people with prediabetes experience feelings of loneliness, confusion, anxiety, and other psychological conditions. Establishing appropriate communication channels for various groups and promoting two-way communication will help enhance low mood of people with prediabetes and increase their knowledge about prediabetes, diabetes, and its various complications. Consequently, addressing the issue of providing more attention and patience to prediabetic people is something that medical providers need to focus on.

Limitations

The research is a qualitative retrospective analysis and has limitations. Firstly, there is a shortage of literature amount that meets the inclusion criteria, and some of the included literatures have unclear preferences and expectations of people with prediabetes, which could impact the final results. Secondly, there is insufficient accurate and standardized information to define patient preferences, expectations, and values. The method used to review the literature and summarize the findings is tentative and empirical, so the results may vary.

Conclusion

In summary, this systematic review shows that drug therapy is typically not the initial option for people with prediabetes. Instead, they prefer to prevent and manage the disease by making lifestyle changes. Prediabetic people hope to receive comprehensive counseling from professionals in their battle against disease. Gender, age, work and other factors affect the choice of treatment for the people with prediabetes.