Jan. 19, 2000 (Washington) -- Whether prompted by fear or good clinical judgment, physicians routinely order billions of dollars' worth of preoperative tests for patients, particularly for older individuals undergoing common procedures such as cataract surgery. But those tests don't seem to matter a bit when it comes to patient outcomes, and, according to the co-author of a study published in the Jan. 20 issue of The New England Journal of Medicine, they should no longer be performed.
"The statement [we] want to make is that people need preoperative histories and physicals, but that routine testing does not produce better outcomes," co-author James M. Tielsch, PhD, tells WebMD. He adds that the research study was purposely designed to "provide more convincing evidence to change practice."
The research, conducted by Oliver D. Schein, MD, MPH, Tielsch, and colleagues from the Dana Center for Preventive Ophthalmology at the Wilmer Eye Institute at Johns Hopkins University in Baltimore, is the first large study to assess the clinical value of tests that are customarily ordered prior to surgery. And although the surgery specifically examined was cataract removal, a co-author and another prominent researcher in the field say the research is applicable to preoperative tests for a host of other surgeries, as long as an adequate history and physical exam are performed prior to the procedures.
"I think there is little doubt on our team that [the findings] certainly apply to a large amount of ophthalmic surgeries," such as glaucoma surgery, some types of retinal surgery, and most corneal surgeries, Tielsch says. Similarly, no routine preoperative testing is necessary for surgeries in which there is little blood loss, and when local anesthesia is used, with or without IV sedation, says Tielsch, a professor of international health who holds joint appointments at the Johns Hopkins schools of medicine and public health.
The investigators hope to convene meetings this spring with internists, anesthesiologists, and surgeons to develop guidelines based on the findings. Initially, they will concentrate on eye surgeries, he says, and likely will address what effect different modes of anesthesiology management may have on adverse events.
According to the study, the federal Health Care Financing Administration, which runs Medicare, spends $150 million annually on routine preoperative tests done before cataract surgery. Based on surveys with ophthalmologists, anesthesiologists, and internists, the authors write that these preoperative tests usually consist of complete blood counts, serum electrolyte measurements, and electrocardiograms (ECGs). In 1996, the most recent year for which statistics are available, some 1.5 million beneficiaries underwent cataract surgery, which the authors describe as "the most commonly performed operation in elderly people in developed countries."
The study compared the adverse events associated with more than 9,400 patients who had preoperative tests with the same number of patients who did not have preoperative tests. Patients were given a letter and study brochure to bring to their provider. Those in the no-testing group were to receive preoperative studies only if they "presented with a new or worsening medical problem that would warrant medication evaluation with testing, even if surgery were not planned," write the authors. Prior to surgery, those in the testing group were given a complete blood count, and measurements of serum electrolytes, urea nitrogen, creatinine, and glucose were taken.
Cumulatively, both groups experienced adverse events in 3% of surgeries. There was no significant difference in the number of adverse events for the testing group vs. the no-testing group. The most common events were high blood pressure and irregular heart rates. "Our study demonstrates that perioperative morbidity and morality are not reduced by routine use of commonly ordered preoperative medical tests," the authors write, adding that they "found no benefit of routine preoperative medical testing ... according to the participating center or the age, sex, or race of the patient."
While he praised the study, one prominent researcher also expressed "fear" about the possible misinterpretation of the findings. Michael F. Roizen, MD, chairman of the department of anesthesiology and critical care medicine at the University of Chicago, who wrote an editorial that was published with the study, tells WebMD he is not confident that routine physicals and medical histories are being taken or that these will be paid for if testing is abandoned.
"There has been a large body of knowledge that has created what I call a compelling rationale for less testing, but there is also the compelling message that if you are going to do less testing, you need also to have a system that ensures an adequate history and physician examination be done," Roizen says.
"Will this get done the way it ought to? I don't know," Roizen says. "Will people put up barriers to it being done right? Absolutely. Obviously, there is a complex of people who profit from more testing, and it is not in their best interest to do less testing. And there are other people, like myself, who will say you can't just stop testing."
Roizen says he also sees the findings as applicable to all minimally invasive surgeries, and perhaps a good deal of moderately invasive procedures, although "we don't have good data on moderately invasive surgeries. Hopefully, this study will allow that [research] to occur."
The federal Agency for Healthcare Research and Quality, which funded the study, will see that these findings are distributed. But beyond that, the agency can't produce guidelines itself, says Hedy Hubbard, the project manager for the cataract research.
"I think it is very compelling, and I think it should be taken seriously," Hubbard tells WebMD. "I don't think the agency is going to take a dramatic stand and say, 'Definitely, no more preoperative testing should be done.' That is dictating care, and we don't do that. We share the information; that is our role."
- In a large study of patients undergoing cataract surgery, those who underwent a series of routine, preoperative tests fared just as well as those who did not receive the tests.
- Researchers say these results could be extended to discourage testing in many types of surgery, including those where there is little blood loss or when local anesthesia is used.
- One expert cautions that routine physicals and medical histories are critical, if preoperative testing is going to be limited.