Standard medical exams routinely performed before cataract surgery do not measurably improve outcomes or reduce deaths or complications from the surgery, according to a Johns Hopkins-led study. "Ending the practice of routine testing could reduce costs without any negative effect on patients' health or clinical outcomes," concludes lead author Oliver D. Schein, professor of ophthalmology at Hopkins' Wilmer Eye Institute.
In a comparative study, patients who underwent routine preoperative tests--including blood counts, blood chemistry and electrocardiography (recording the electrical activity of the heart)--fared as well as patients who had surgery without them, Schein adds. Such testing adds an estimated $150 million in direct costs to Medicare each year, he says.
Results of the study of more than 19,000 patients at nine medical centers were published in the Jan. 20 issue of the New England Journal of Medicine.
Cataract surgery is the most commonly performed operation in elderly people in developed countries. In the United States, Medicare beneficiaries underwent 1.5 million cataract operations in 1996, the last year for which full information is available. The surgery is most often done on an outpatient basis using local anesthesia, and death rates are low. Because cataract patients are usually older and have illnesses, physicians routinely order preoperative tests.
At the nine medical centers, including Wilmer, researchers randomly assigned more than 19,000 elective cataract operations to be preceded or not preceded by a standard battery of tests. Any medical complications occurring on the day of surgery or during the following seven days were recorded.
Medical outcomes were assessed in 9,408 patients who underwent 9,626 cataract operations not preceded by routine testing and in 9,411 patients who underwent 9,624 operations that were preceded by routine testing. The most frequent medical events in both groups during surgery and the following week were rises in blood pressure and a slowed heart rate. Serious medical events were rare. But the overall rate of complications was the same in the two groups--31.3 events per 1,000 operations. Researchers observed no benefit of routine preoperative medical testing when analyzing the results by the patient's age, sex, race or co-existing medical conditions.
In a national survey conducted prior to the study, most ophthalmologists, anesthesiologists and internists said they routinely ordered complete blood counts, measurements of serum electrolytes and electrocardiograms preoperatively. Other tests, such as chest radiography, blood-clotting studies and urinalysis also were ordered frequently.
"Many physicians believed the tests were unnecessary but ordered them anyway because of institutional requirements, legal concerns or a belief that another physician wanted them performed," Schein says. "Based on this study, we recommend that tests be ordered only when the history or a finding on physical examination would have indicated the need for a test even if surgery had not been planned."
The other authors were Joanne Katz, Eric B. Bass, James M. Tielsch, Lisa H. Lubomski, Marc A. Feldman and Brent G. Petty, all of Hopkins; and Earl P. Steinberg, of Hopkins and Covance Health Economics and Outcomes Services, Washington.