A.S. Hedayat is a distinguished professor of Statistics and Senior Scholar at the Department of Mathematics, Statistics, and Computer Science, University of Illinois at Chicago. Its main areas of research and statistical advice are the design of experiments, medical and pharmaceutical statistics, environmental statistics, medicinal statistics, monitoring strategies, evaluation of agreements and sampling. In addition to the traditional periodic publications of more than 160 articles, he has also co-authored three books on statistics. Professor Hedayat is a Fellow of the Institute of Mathematical Statistics, a Fellow of the American Statistical Association and an elected member of the International Statistical Institute. He has worked in the editorial boards of numerous international magazines, including The Annals of Statistics, American Statistical Association, The American Statisticians and the Bulletin of Iranian Mathematical Society. In 2010, we searched Medline, Ovid, PubMed, Scopus and Science Direct for studies on the agreement of medical instruments or devices published in magazines between January 2007 and December 2009. The Boolean search was conducted for each database with the search term: agreement ET (validation or “comparative study”). Research has been limited to the medical field (including dentistry), studies on human subjects and articles in English. This study finds that the Bland-Altman method is the most popular method used in contract research. In some studies, there are still inappropriate applications of statistical methods. It is important for a physician or medical researcher to be aware of this problem, as misleading findings from inappropriate analyses compromise the quality of evidence, which will affect the quality of patient care in the future.

Wenting Wu is a senior statistician at the Mayo Clinic Cancer Center and a biostatistics assistant at the Mayo Clinic Graduate School. His research focuses on the areas of cancer clinical trial design and measurement agreements. Areas of active research include randomized Phase II studies; Meta-analyses Predictive factor analysis; and clinical efficacy selection of the terminus point in Phase II/III studies. Over the past five years, Dr. Wu has published more than 40 expertly reviewed articles, 2 book chapters and more than 20 conference letters and abstracts. She has also worked as a statistical critic for approximately 10 international journals. The exact values are a must in medicine. An important parameter for determining the quality of a medical instrument is compliance with a gold standard. Different statistical methods have been used to test compliance. Some of these methods have proven to be inappropriate. This can lead to misleading conclusions about the validity of an instrument. The Bland-Altman method is the most popular method that is judged on the basis of the many quotes in the article that proposes this method.