Screening Didn't Cut Diabetes Death Rates

Type 2 diabetes screening programs not associated with reduced mortality rates

(RxWiki News) The growing rate of type 2 diabetes is a major public health problem in the U.S. Screening and early treatment for diabetes could reduce this problem. However, researchers are still uncertain about the benefits of screening.

Screening for type 2 diabetes in high-risk patients did not reduce rates of death within 10 years, according to recent findings.

"Manage your diabetes carefully."

According to Dr. Simon Griffin, of Addenbrooke's Hospital in the UK and co-author of the study, the high numbers of undiagnosed cases of diabetes, the high rates of complications at the time of diagnosis and the long latent stage of diabetes are all good reasons for screening.

"However, in the large UK sample that we studied, screening for type 2 diabetes in patients at increased risk of the disease was not associated with any reduction in mortality within 10 years," he said.

For their study, Dr. Griffin and colleagues compared three screening groups:

  • A group that went through one round of screening followed by intensive care for patients diagnosed with diabetes
  • A group that went through one round of screening followed by standard care for diagnosed patients
  • A control group that was not screened for diabetes

The screening groups had similar rates of death as the control group, with a hazard ratio of 1.06.

A hazard ratio explains how much an event happens in one group versus another. A hazard ratio of more than 1.0 means the event happens more in one group than the other. In this case, a hazard ratio of 1.06 means that the death rate was higher in the screening groups than in the control groups.

Even when the researchers looked at specific causes of death, screening did not reduce the rates of death.

Compared to patients who did not get screened, those who were invited to get screening had a higher risk of:

  • cardiovascular death, with a hazard ratio of 1.02
  • cancer death, with a hazard ratio of 1.08
  • diabetes-related death, with a hazard ratio of 1.26

"It seems that the benefits of screening might be smaller than expected and restricted to individuals with detectable disease," said Dr. Griffin.

However, he added that the benefits could be boosted by including screening and management of cardiovascular risks alongside screening for diabetes, doing multiple rounds of screening and improving efforts to encourage people to get screened.

Even though the research had a large sample size, the authors noted that their study had some limitations. One specific limitation was the fact that the study took place in a wealthy area of the UK. The authors said that these findings should not be applied to people from less advantaged communities, where the risk of diabetes may be higher and rates of screening may be lower.

Commenting on the study, Michael Engelgau of the Centers for Disease Control and Prevention (CDC) said that diabetes screening and diagnosis are relatively easy to do, which further boosts support for wide-scale screening. However, these arguments do not account for the costs of screening, possible risks and the lack of evidence that screening improves outcomes compared to the current standard diagnosis, said Dr. Engelgau.

"This study increases the doubt about the value of wide-scale screening for undiagnosed diabetes alone," he said.

The study population consisted of more than 20,000 people between 40 and 69 years of age at high risk of existing, undiagnosed diabetes. Of the 16,047 high-risk participants in screening practices, 15,089 (94 percent) were invited to be screened, 11,737 (73 percent) followed through with screening and 466 (3 percent) were diagnosed with diabetes.

The research was funded by the Wellcome Trust, UK Medical Research Council and the UK National Institute for Health Research among others.

The study was published October 4 in The Lancet.

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Review Date: 
October 4, 2012