Researchers looked at the number of deaths over 10 years among more than 20,000 people, aged 40 to 69. All of them were at high risk for diabetes.
The patients were divided into three groups. One group underwent a round of diabetes screening that was followed up by routine care for those diagnosed with diabetes; another group had a round of screening followed by intensive management for those diagnosed with diabetes; and a third group did not undergo diabetes screening.
Over an average follow-up of nearly 10 years, the overall death rates in the groups that had diabetes screening were no lower than in the group that had no screening. There also was no significant difference between the groups in the number of deaths specifically from diabetes, cardiovascular illness, cancer or other causes.
Study author Dr. Simon Griffin, of the epidemiology unit at Addenbrooke's Hospital in Cambridge, said in a journal news release, "It seems that the benefits of screening might be smaller than expected and restricted to individuals with detectable disease." "However, benefits to the population could be increased by including the detection and management of cardiovascular risk factors alongside the assessment of diabetes risk, performing repeated rounds of screening and improving strategies to maximize the uptake of screening."
Michael Engelgau, of the U.S. Centers for Disease Control and Prevention, wrote in an accompanying editorial, "Diabetes screening and diagnosis can be done with relative ease, which further escalates popular support for wide-scale screening." "However, these compelling arguments overlook the screening costs, potential harm and lack of clear evidence that screening improves health outcomes compared with current routine clinical diagnosis."
"This study increases the doubt about the value of wide-scale screening for undiagnosed diabetes alone, and deserves credit for tackling the screening quandary head-on," Engelgau concluded. "Nevertheless, for any one study to address the diverse factors that affect screening policies -- ranging from the magnitude of population burden of disease to the capacity and effectiveness of prevention approaches -- is a tall order. Screening recommendations are therefore likely to be country specific and context specific for the foreseeable future."
The Lancet, news release, Oct. 3, 2012