Physicians, Patients Should Verify Quality of Trials

Clinical trials from years ago may not hold up to today's standards, according to the March 1, 2003, issue of the International Journal of Radiation Oncology, Biology and Physics, the official journal of ASTRO, the American Society for Therapeutic Radiology and Oncology. Because older trials are still sometimes used to help determine the best treatment for a patient, it is important for physicians and patients to make sure that only high-quality trials are used when deciding on treatment plan.

In the last few years, physicians have become increasingly reliant upon the outcome of randomized clinical trials when making treatment decisions, and are less dependent on anecdotal evidence. This movement toward what is called "evidence-based medicine" has grown along with an emphasis on the scientific nature of medicine. Many physicians now routinely engage in a clinical learning strategy that involves systematically finding, appraising and using current research findings as the basis for clinical decisions.

In the study, researchers examined how the role of radiotherapy in treating breast cancer has changed over the years as the quality of evidence evolved from anecdotes based on expert opinion to randomized clinical trials and meta-analyses. After searching the medical literature for key randomized trials and meta-analyses dating back to the 1950s that have influenced the use of post-mastectomy radiation, the researchers assessed how clinical practice changed based on the outcomes of those trials. They also examined the quality of those studies based on the criteria currently used to assess evidence from randomized trials.

The researchers found that the earlier trials had a strong effect on shaping clinical practice. They also found that these studies had significant flaws in design, and many do not meet today's evidence-based standards. As a result, it is important for patients and physicians to continually assess that the quality of evidence from these and other trials. According to the study, researchers must adhere to guidelines developed to critique both randomized trials and meta-analyses to establish high standards for trial design and interpretation. Likewise, researchers should carefully review older trials that did not adhere to the currently accepted standards, particularly when results from those trials are frequently updated and used to generate new clinical evidence and when those trials are included in meta-analyses.

"Evidence-based medicine is and can be a powerful tool in changing clinical practice patterns. Keeping abreast of the latest research findings and learning new treatment approaches takes time and effort. Also, evidence-based medicine must be tempered by clinical judgment," said Seymour H. Levitt, M.D., D.Sc., Professor of Radiation Oncology at the University of Minnesota. Dr. Levitt is the lead author of the study as well as a past president of ASTRO. "It is important for doctors to use both their individual clinical expertise and the best available clinically relevant research when making decisions for individual patients."

The American Society for Therapeutic Radiology and Oncology is the largest radiation oncology society in the world, with more than 7,000 members who specialize in treating patients with radiation therapies. As a leading organization in radiation oncology, biology and physics, the Society's mission is to advance the practice of radiation oncology by promoting excellence in patient care, providing opportunities for educational and professional development, promoting research and disseminating research results and representing radiation oncology in a rapidly evolving socioeconomic healthcare environment.