Annual retinopathy screening: Is it a must?
Biennial screening may be just as effective
At a time when many health care organizations have been judged deficient in their diabetes care because of low compliance on annual retinopathy exams, new studies suggest annual screens may not be cost-effective, or necessary, for patients who show no signs of retinopathy.
The study from the U.S. Veteran’s Affairs Health Services Research Center at the University of Michigan in Ann Arbor was published in the Feb. 16 issue of the Journal of the American Medical Association. It drew a quick expression of concern from the American Diabetes Association in Alexandria, VA, which immediately issued a written statement reiterating its recommendation for annual eye screenings for all patients with diabetes.
The Michigan team was led by Sandeep Vijan, MD, MS, investigator at the VA and assistant professor of Internal medicine at the University of Michigan. The researchers concluded that a high-risk patient who is age 45 and has an HbA1c of 11% gains 21 days of sight when screened annually as opposed to every third year. A low-risk patient who is 65 and has an HbA1c of 7% gains an average of three days of sight.
Their results showed patients in the high-risk group cost an additional $40,530 per quality-adjusted life-year (QALY), while the low-risk group cost an additional $211,570 per QALY gained. In the general population, annual retinal screening vs. every-other-year screening costs $107,510 per QALY gained, and screening every other year vs. every third year costs $49,760 per QALY gained.
Annual screening not cost-effective
"Annual retinopathy screening has always been the gold standard in diabetes care, but it’s not really based on scientific analysis," says Vijan. He suggests biennial or even triennial screening would save money and be just as medically effective.
The ADA fired back. "The . . . study relies on computer modeling, not clinical results, so its relevance to actual outcomes may be less certain."
Ronald Klein, MD, professor of ophthalmology at the University of Wisconsin in Madison, echoes the concerns of the ADA and adds a few of his own. "I have no difficulty with the data they present, but the interpretation needs to be carefully examined."
The data are based on computer modeling, and there is a lack of what Klein calls "good epidemiological data to support what the authors suggest needs to be done." He also expresses concern that the subjects in the trial were from a predominantly white population from the Third National Health and Nutrition Examination Survey (NHANES III), by the National Center for Health Statistics. "Diabetic retinopathy may behave differently in other ethnic groups, particularly in Hispanics and blacks."
Klein agrees with Vijan that the timing of screenings should be determined on a case-by-case basis. "The ADA guidelines [on retinopathy] were developed in the 1980s based on epidemiological studies at a time when people were coming to ophthalmologists late in the game after they had already developed retinopathy."
The ADA statement expressed concerns that Vijan’s study "only examined the value of screening to prevent blindness, but there are serious consequences of visual impairment short of becoming blind. These consequences also can be prevented or delayed by early detection [i.e. annual screening]. Thus screening to prevent or delay a reduction in visual acuity should, we believe, be quite valuable for most patients with diabetes."
The ADA statement also said the current annual rate of eye exams is estimated to be only 40% to 50% of eligible patients, despite the current recommendation to screen annually. "As such, it is uncertain whether a recommendation to reduce the frequency may lead to even less screening of those eligible or in need of screening." The ADA also expressed concern about the ability of health care professionals who treat people with diabetes to easily identify high-risk vs. low-risk diabetic patients and that follow-up to monitor eye exam referrals is not common.
"We don’t want less compliance. But if we lower the burden on both patients and physicians, I think we might actually get increased compliance," Vijan counters.
[Contact Sandeep Vijan at (734) 930-5100 and Ronald Klein at (608) 263-0280. The American Diabetes Association may be reached at (703) 549-1500. The ADA Web site is: http://www.diabetes.org]