Research has shown that more than 60 million adults in the United States have diagnosed diabetes, undiagnosed diabetes, or prediabetes. “Approximately 30% of diabetes cases are estimated to be undiagnosed,” says Heejung Bang, PhD. “Diabetes is a silent killer and many patients don’t know they have it, but clinicians can help patients by steering them to assess their risk on their own. With the steadily increasing prevalence of the disease, prevention of diabetes has become a major health priority, and the identification of high-risk people who may benefit from early lifestyle interventions is paramount.”
National guidelines for diabetes screening are available to help detect undiagnosed disease. In addition, several risk assessment tools for prevalent or incident diabetes have been developed to identify patients who are most in need of screening. In the United States, national guidelines for diabetes screening have been released by the CDC, the American Diabetes Association (ADA), and the Preventive Services Task Force. In addition, two risk-scoring algorithms for undiagnosed diabetes have been derived from nationally representative samples. These methods have been developed using slightly different frameworks and purposes, but they are not widely used. “They often target specific populations,” says Dr. Bang, “and therefore may not be applicable to the general population, or may not be that simple to use.”
A New Screening Tool
In the December 1, 2009 Annals of Internal Medicine, Dr. Bang and colleagues had a study published detailing the development of a new screening score for undiagnosed diabetes in multi-ethnic U.S. adults by using readily-available health information. “Our aim was to improve existing algorithms for diabetes-risk scoring by using more contemporary National Health and Nutrition Examination Survey (NHANES) data and formulating an easy, systematic scoring system that enables lay people to assess their own risk. Our mission was to further improve early diagnosis in order to prevent or delay disease onset.”
“With the steadily increasing prevalence of the disease, prevention of diabetes has become a major health priority and the identification of high-risk people who may benefit from early lifestyle interventions is paramount.”
– Heejung Bang, PhD
The study team developed a six-item questionnaire, which scores risk factors for diabetes, including age, gender, and exercise (Table 1). To develop the tool, researchers used data from NHANES from 1999-2004. The sample was composed of 5,258 multi-ethnic adults, all aged 20 or older. A statistical analysis identified characteristics that were independently associated with undiagnosed diabetes. After the scoring system was developed, it was validated and compared with other screening methods using data from NHANES 2005-2006 along with a combination of two large community studies, the Atherosclerosis Risk in Communities study and the Cardiovascular Health Study.
The algorithm developed by Bang et al was found to be more accurate than methods developed by the CDC, the ADA, and the Preventive Services Task Force guidelines as well as two other risk questionnaires and the Rotterdam model, which is a European tool. “Our diabetes score seemed to perform better than existing methods by quantitative criteria,” says Dr. Bang. “We believe that it also has good feasibility characteristics. It’s both simple and efficient, using six easily answered health-related questions with minimal time needed for survey completion and no need for calculators. Our screening correlated with better rates of test accuracy (sensitivity plus specificity), positive predictive values, and positive likelihood ratios than the other screenings studied [Table 2].”The new algorithm can be used in a wide variety of community and clinical settings, including patient waiting rooms, online, or using pencil and paper, says Dr. Bang. “The same questionnaire can be used for pre-diabetes as well as diabetes. By highlighting risk factors for the disease, this tool may help motivate people to be screened or perhaps spark a discussion with their physicians or encourage them to adopt healthier lifestyles. It may serve as a way to address the lack of interaction with healthcare facilities and providers that may underlie the high percentage of the population with undiagnosed diabetes, particularly the underserved.”
More Education Warranted
Although patients are increasingly aware of the dangers of diabetes and its complications, more education is still needed in community and clinical settings. “Although further validation of our screening score in other samples is important, it’s our belief that this tool can still have immediate applications. It can be used in clinical encounters, targeted screenings, and health education programs, but it can also be applied by health plans to existing databases for case findings. The new algorithm may also help identify optimal populations for enrollment in clinical trials that test new strategies to prevent or manage diabetes. We’re excited about this new, practical screening tool because this simple questionnaire can provide more accurate information about who should undergo further screening. It has great potential to lessen the disease burden.”
Bang H, Edwards AM, Bomback AS, et al. A self-assessment diabetes score: development, validation, and comparison with other diabetes risk-assessment scores. Ann Intern Med. 2009;151;775-783. .
Cowie CC, Rust KF, Ford ES, et al. Full accounting of diabetes and pre-diabetes in the U.S. population in 1988-1994 and 2005-2006. Diabetes Care. 2009;32:287-294.
Heikes KE, Eddy DM, Arondekar B, Schlessinger L. Diabetes Risk Calculator: a simple tool for detecting undiagnosed diabetes and pre-diabetes. Diabetes Care. 2008;31:1040-1045.
American Diabetes Association. Standards of medical care in diabetes—2009. Diabetes Care. 2009;32 (Suppl 1):S13-S61.
U.S. Preventive Services Task Force. Screening for type 2 diabetes mellitus in adults: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2008;148:846-854.