Introduction
Diabetes mellitus is a chronic metabolic disorder that occurs due to the inability of the body to regulate the level of glucose in the blood. Depending on the cause, there are two types of diabetes mellitus, type 1 and type 2. Type 1 diabetes mellitus occurs due to the insufficiency of insulin in the body caused by the destruction of beta cells, while type 2 occurs due to the insensitivity or resistance of peripheral tissues to insulin. Moreover, type 1 diabetes mellitus affects children while type 2 diabetes mellitus affects adults. Women also experience gestational diabetes mellitus during pregnancy period. In this view, since the type of diabetes varies according to age and gender, its screening is complex. The screening of diabetes mellitus requires different screening strategies or techniques that suit demographic and biochemical needs of the patients. The complexity of diabetes screening has necessitated the development of screening standards, which are effective, specific, and sensitive (American Diabetes Association, 2011). Health care systems across the world are employing diverse screening strategies and criteria in the diagnosis of diabetes mellitus among the population.
Since criteria for screening diabetes across the world vary from one health care system to another, different regulatory bodies have adopted different criteria and guidelines. In the United States, the criteria and guidelines for screening diabetes mellitus are many, and thus complicating the diagnosis of diabetes mellitus in the population. Glycated hemoglobin (A1C) is one of the criteria that are applicable in the diagnosis of diabetes among the population. Owing to diversity of screening criteria, the International Diabetes Federation (IDF), the European Association for the Study of Diabetes, and other international bodies recommended the use of the A1C criteria in the diagnosis of diabetes in 2009, because it is accurate when compared with other methods of screening. In 2010, American Diabetes Association (ADA) adopted A1C criteria as a standard method of screening people for pre-diabetes, in that, individuals with 5.7% to 6.4% A1C levels are at high risk of developing diabetes (Mann, Carson, Shimbo, Fonseca, Fox, & Muntner, 2010). The A1C levels that are greater than 6.5% are for diabetic individuals. In this view, healthcare providers currently apply A1C screening strategy according to the standards and guidelines outlined by the National Glycohemoglobin Standardization Program (NGSP).
Prior to the use of A1C, fasting plasma glucose (FPG) and oral glucose tolerance test (OGTT) are other screening criteria that are applicable in the diagnosis of diabetes mellitus. FPG considers the blood glucose level of 126 mg/dl as diabetic threshold. To obtain accurate results of FPG, healthcare providers should perform diagnosis at least after 8 hours of fasting. The length of fasting is a significant factor that determines the accuracy of FPG in the diagnosis of pre-diabetes and diabetes. In the screening of diabetes using the OGTT, a 2-hour fasting is essential after one has consumed 75g of glucose. The cut point of diabetes using OGTT is glucose level that is greater than 200 mg/dl. According to Somannavar, Ganesan, Deepa, Datta, and Mohan (2009), a 2-hour OGTT is a sensitive and specific criterion when applied according to the guidelines presented by the World Health Organization. Due to the accuracy of FPG and OGTT, ADA also recommends their use in screening pre-diabetes and diabetes.
In addition to diabetes screening, diabetes education is another criterion that is applicable in the management of diabetes among the diabetic population. Given that diabetes is a complex metabolic disorder, patients requires comprehensive information regarding lifestyle strategies of managing diabetes. Diabetes self-management education (DSME) is the national standard of managing diabetes among diabetic patients because it prevents the occurrence of associated complications, optimizes metabolic control, and improves quality of life. Healthcare providers should match education that they provide to patients with their literacy levels, culture, and understanding of diabetes to improve effectiveness of DSME (Elliot, Abdulhadi, Al-Maniri, Al-Shafaee, & Wahlstrom, 2013). Therefore, DSME is one of the standard practices that are applicable in the management of diabetes as presented by the Agency for Healthcare Research and Quality (AHRQ).
Since the health care system is facing enormous challenges in the screening and management of diabetes, AHRQ in conjunction with ADA and other regulatory bodies have developed criteria and guidelines that are applicable in the diagnosis and management of diabetes. In this case, the research paper seeks to analyze standards of screening such as A1C, FPG, and OGTT. Moreover, the research paper examines DSME as standard of management with objective of providing appropriate recommendations for the diagnosis and management of diabetes.
Theoretical Foundation
Since the health care system is grappling with the challenge of standardizing criteria for diagnosing diabetes, the appropriate nursing theory is the prescriptive theory by Ernestine Wiedenbach. The prescriptive theory of nursing perceives nursing as an art and practice of assessing the needs patients relative to their health conditions. The prescriptive theory is a theory that enables nurses to make informed decisions and judgment regarding the conditions of their patients. Essentially, the theory enhances decision-making and judgment processes, which nurses practice before undertaking any intervention on a patient. Given that the diagnosis of diabetes is a process that entails screening using diverse criteria, the theory aids nurses to apply their judgment and decision-making capacity in ascertaining whether an individual has diabetes or not. Application of varied methods of screening gives different classifications of patients such as normal, pre-diabetic, and diabetic individuals. According to Mann, Carson, Shimbo, Fonseca, Fox, and Muntner (2010), application of A1C criterion would reclassify 37.6 million of Americans with impaired fasting glucose as pre-diabetes and reclassify 8.9 million who do not have impaired fasting glucose as pre-diabetes. The differences in specificity and sensitivity of the screening methods require nurses to apply their knowledge, skills, and judgment in line with prescriptive theory. Therefore, nurses should understand the impact of using different methods in the diagnosis of diabetes and diabetes.
DSME is a management standard that is central to the management of diabetes. The appropriate theory that is applicable in enhancing effectiveness of DSME in the management of diabetes is the self-care deficit nursing theory by Dorothea Orem. The theory holds that human behavior and habits are essential in adopting healthy practices. Nursing systems theory, self-care theory, and self-care deficit theory are three theories that make up Orem’s theory. The nursing systems theory requires application of systems that supports education of patients with diabetes. In this view, patients should have sufficient knowledge and skills for them to perform self-care practices. Elliot, Abdulhadi, Al-Maniri, Al-Shafaee, and Wahlstrom (2013) argue that some cultural and religious beliefs affect knowledge and skills of patients, and thus make them adopt dangerous strategies in self-management of diabetes. According to self-care theory, literacy levels of patients determine their ability to manage diseases, and thus they require essential knowledge and skills. Moreover, the self-care abilities vary according to gender, age, family, society, and health care system. Regarding the theory of self-care deficit, the theory states that deficit of self-care knowledge and skills worsen the conditions of the patients. Thus, the Orem’s theory of self-care deficit is applicable in the optimization of DSME in the management of diabetes.
The Review of the Literature
To analyze standards and guidelines that healthcare providers utilize in the diagnosis and management of diabetes according to the criteria presented by the American Diabetes Association (2011), the research paper searched articles from databases such as NCBI, CNAHL, PubMed, and Diabetes Care. The search terms that were used in the databases are screening of diabetes, diagnosis of diabetes, A1C, fasting plasma glucose, gestational diabetes, management of diabetes, and diabetes self-management education. The search terms revealed that ADA, IDF, AHRQ, and other international bodies of diabetes have agreed that A1C, FPG, OGTT are some of the reliable criteria for screening diabetes and pre-diabetes, while DSME is a strategy of managing diabetes among various populations.
The A1C Criterion
Regarding the A1C criterion, ADA has recommended its application in the diagnosis of diabetes and pre-diabetes because it is an accurate method. In 2010, ADA adopted A1C as a standard of screening diabetes according to the guidelines of NGSP. ADA recognizes the cut point of diabetes as 6.5% and cut point of pre-diabetes as 5.7%. This means that individuals with more than 6.5% A1C level have diabetes while individuals with A1C levels between 5.7% and 6.4% have pre-diabetes. According to a cross-sectional survey conducted to examine the accuracy of the A1C criterion when compared with impaired plasma glucose, the findings showed that there are significant implications in the diagnosis of diabetes and pre-diabetes. The cross-sectional study has A level of evidence. The findings showed that the A1C screening of pre-diabetes has predictive positive value of 61%, predictive negative value of 77%, sensitivity of 27%, and specificity of 93% (Mann, Carson, Shimbo, Fonseca, Fox, & Muntner, 2010). The findings revealed that A1C has the highest specificity, but the lowest sensitivity in the diagnosis of diabetes and pre-diabetes. The strength of the study is that it employed a cross-sectional survey as a design, and therefore, it improved validity of data due to reduced biasness. Moreover, the strength of the study is that it used 7975 adults from the population, and thus increasing the external validity. Essentially, the findings supported application of A1C as a guideline of screening diabetes and pre-diabetes.
In a retrospective study conducted to determine the effectiveness of Universal, Irish, ADA, and NICE screening strategies in the diagnosis of gestational diabetes mellitus, the findings revealed that ADA criterion of using A1C is effective. The level of evidence in the retrospective study is B. According to Avalos, Owens, and Dunne (2013), ADA procedure is the best screening strategy with a specificity of 44% and a sensitivity of 80%. The strength of the study is that it employed a large sample of participants (5500), and thus enhanced the external validity of the findings. Moreover, the study also compared common strategies of screening diabetes. The comparative study of common strategies for screening diabetes led to the realization that ADA is the most effective strategy of screening GDM. However, the weakness is that ADA has low specificity; hence, reduced the accuracy of measuring GDM among pregnant women. Overall, the study supported the guideline of using the ADA strategy in the diagnosis of GDM because it is very sensitive when compared to NICE, Irish, and Universal strategies.
In a comparative case study, A1C criterion proved to be ineffective in detecting diabetes and pre-diabetes because it missed many cases. The case study has a B level of evidence. The A1C criterion missed 71-84% of dysglycemia, 70% of diabetes, and 82-94% of pre-diabetes (Olson, Rhee, Herrick, Ziemer, Twombly, & Philips, 2010). These findings further proved that A1C has a low sensitivity, but has a high specificity in the diagnosis of diabetes and pre-diabetes. Hence, it implies that healthcare providers need to employ A1C and other methods of screening to enhance sensitivity of the A1C and obtain accurate results. The strength of the study is that it used a large sample of participants (4706), which increased the external validity of the findings and consequently their extrapolation among diverse populations. However, the accuracy of using A1C is not reliable because A1C is not sensitive enough to measure diabetes and pre-diabetes. Owing to the high specificity of A1C, the study supported the application of A1C in the diagnosis of diabetes and pre-diabetes according to the guidelines recommended by ADA.
Fasting Plasma Glucose (FPG) Criterion
FPG is another criterion that is applicable for screening diabetes. FPG is a criterion that healthcare providers have used for decades in screening diabetes. ADA had recommended the use of the FPG criterion in the screening of diabetes basing on the cut points of 126 mg/dl for diabetes and 100 mg/dl for pre-diabetes. According to a research conducted in India, FPG is accurate because it had a sensitivity of 89.4% and specificity of 80.2% (Somannavar, Ganesan, Deepa, Datta, & Mohan, 2009). The level of evidence of this research is B. These findings showed that FPG is an accurate criterion of screening diabetes because it relies on the capacity of an individual to maintain a certain level of blood plasma during fasting. In this view, the study recommended the use of FPG in screening diabetes and pre-diabetes among diverse communities because it is stable and accurate. The strength of the study is that, since the study selected 1333 participants, it enhanced the external validity of findings, and thus their extrapolation among diverse populations. However, the weakness is that the study was conducted among Asian Indians only, which limited external validity of the findings. Fundamentally, the study supported application of FPG as a guideline of screening diabetes and pre-diabetes.
Oral Plasma Glucose Tolerance (OGTT) Criterion
OGTT is a common criterion that was applicable in the diagnosis of diabetes among the population. OGTT is a gold standard in the diagnosis of diabetes and pre-diabetes because it is not only sensitive and specific, but also stable from one population to another. Standard OGTT requires an individual to consume 75g of glucose and plasma glucose level determined after two hours. In a case study that compared A1C and OGTT, the findings established that OGTT is more sensitive than A1C. The case study has a B level of evidence as it examined a large number of participants. Olson, Rhee, Herrick, Ziemer, Twombly, and Philips (2010) stated that OGTT and A1C were intrinsically different because OGTT is best in screening day-to-day level of blood glucose, while A1C is best in screening glycemic trends over a long period like months. Since A1C measured glycemic trends over a long period, it did not give accurate results that depicted a real-time level of plasma glucose. In this view, OGTT is the best criterion for diagnosing diabetes and pre-diabetes based on 75g of glucose consumed.
Diabetes Self-Management Education (DSME)
DSME is one of the effective strategies of managing diabetes among the population because it empowered patients to understand how to apply self-care strategies. A quasi-experiment that was performed among Latinos and Hispanics revealed that DSME had significant impact on glycemic levels of the participants. The quasi-experiment has A level of evidence because the study assigned individuals randomly to control and intervention group. According to Pena-Purcell, Boggess, and Jimenez (2011), DSME significantly enhanced self-care abilities of diabetic patients in the intervention group and improved their glycemic control capacity when compared to control group. Hence, the findings proved that DSME is effective in the management of diabetes. The quasi-experiment design that the study employed is the strength because it increased validity of the findings. However, the weakness is that the study targeted small sample of participants who were above 40 years. Such sample of participants gives the findings a low external validity because they are only applicable among Hispanics and individuals above 40 years. Generally, the study supported application of DSME as a guideline of managing diabetes according to recommendation of ADA.
In a survey conducted in Oman among adult people who had the ages of 18 years and above, the survey indicated that the majority of diabetic patients were unable to manage their conditions effectively because they had dangerous beliefs and practices. The survey has a C level of evidence because it surveyed 309 individuals with type 2 diabetes. Elliot, Abdulhadi, Al-Maniri, Al-Shafaee, and Wahlstrom (2013) reported the findings that, about a quarter (26%) of participants were unable to recognize hypoglycemia and respond to it, while approximately 49% and 60% were unable to recognize hyperglycemia and respond to it respectively. In this view, the survey suggested that there is an urgent need to improve knowledge and skills among diabetic patients in Oman. The strengths of the survey are that it used many variables to measure knowledge and skills among diabetic patients, and employed enough sample of population to warrant generalization of findings. In this view, the survey supported the application of DSME as a guideline of improving management diabetes among diabetic patients.
Recommendations
- The reviewed articles perceive A1C as an insensitive criterion of diagnosing diabetes and pre-diabetes. According to Mann, Carson, Shimbo, Fonseca, Fox, and Muntner (2010), A1C has a sensitivity of 27%, and specificity of 93% A1C. Comparatively, Olson, Rhee, Herrick, Ziemer, Twombly, and Philips (2010) also argue that A1C has many false-negatives as it misses 71-84% of dysglycemia, 70% of diabetes, and 82-94% of pre-diabetes. As A1C criterion is racially discrepant and insensitive in measuring both diabetes and pre-diabetes, healthcare providers should utilize it in conjunction with other screening methods.
- As FPG is a standard method that is applicable in the diagnosis of diabetes and pre-diabetes, the literature review supports it. According to Somannavar, Ganesan, Deepa, Datta, and Mohan (2009), FPG is accurate because it has a sensitivity of 89.4% and specificity of 80.2%. This means that healthcare providers should continue using FPG as a gold standard in the diagnosis of diabetes and pre-diabetes.
- The literature review also supports the application of OGTT as a criterion of screening diabetes and pre-diabetes. According to Olson, Rhee, Herrick, Ziemer, Twombly, and Philips (2010), OGTT is important because it determines day-to-day level of blood glucose accurately. In this view, healthcare providers should apply OGTT criterion in determining diabetes and pre-diabetes after one consumes 75g of glucose.
- Given that a significant number of diabetic patients lack sufficient knowledge and skills that are essential in self-management of diabetes, literature shows that DSME is an effective strategy of improving the ability of individuals to manage diabetes. The findings of an experiment revealed that DSME significantly improved self-care knowledge and skills, as well as glycemic control among the intervention group when compared to the control group (Pena-Purcell, Boggess, & Jimenez, 2011). Thus, healthcare providers should use customized DSME in the management of diabetes because it is an effective strategy.
Conclusion
Since diabetes is a complex metabolic disorder, health care system and related bodies have developed numerous standards and guidelines that are applicable in the screening and management of diabetes. ADA recommends the use of A1C, but the ample literature review indicates that it is insensitive criterion. However, FPG and OGTT are criteria that are accurate because they have a high level of sensitivity and specificity. In the management of diabetes, literature review shows that DSME is an effective method of enhancing self-care knowledge and skills among diabetic patients. Therefore, the research paper recommends that ADA and other bodies should provide various criteria as standards to enhance sensitivity and specificity of screening diabetes. Regarding management of diabetes, ADA should develop customized DSME that suit unique needs of diverse communities across the world.
References
American Diabetes Association (2011). Standards for Medical Care in Diabetes-2011. Diabetes Care, 34(1), 11-61.
Avalos, G., Owens, L., & Dunne, F. (2013). Applying Current Screening Tools for Gestational Diabetes mellitus to a European Population: Is It Time for Change? Diabetes Care, 36(10), 3040-3044.
Elliot, J., Abdulhadi, N., Al-Maniri, A., Al-Shafaee, M., & Wahlstrom, R. (2013). Diabetes Self-Management and Education of People Living with Diabetes: A Survey in Primary Health Care in Muscat Oman. PLOS ONE, 8(2), 1-7.
Mann, D., Carson, A., Shimbo, D., Fonseca, V., Fox, C., & Muntner, P. (2010). Impact of A1C Screening Criterion on the Diagnosis of Pre-Diabetes among U.S. Adults. Diabetes Care, 33(10), 2190-2195.
Pena-Purcell, N., Boggess, M., & Jimenez, N. (2011). An Empowerment-Based Diabetes Self-Management Education Program for Hispanic/Latinos. The Diabetes Educator, 37(6), 770-779.
Olson, D., Rhee, M., Herrick, K., Ziemer, D., Twombly, J., & Philips, L. (2010). Screening for Diabetes and Pre-Diabetes with Proposed A1C-Based Diagnostic Criteria. Diabetes Care, 33(10), 2184-2189.
Somannavar, S., Ganesan, A., Deepa, M., Datta, M., & Mohan, V. (2009). Random Capillary Blood Glucose Cut Points for Diabetes and Pre-Diabetes Derived from Community-Based Opportunistic Screening in India. Diabetes Care, 32(4), 641-643.