A statistical sampling of data from U.S. Hospital discharge information revealed a correlation between nonperforating appendicitis and nonperforating diverticulitis. We used a method called cointegration to research common motions in epidemiologic data series, said Fomby, a professor of economics at SMU, who led the statistical analysis with statistician Wayne A. Woodward, professor and department chair in SMU’s Department of Statistical Science. Business lead author on the analysis was Edward H. Livingston, M.D., in the division of Endocrine and Gastrointestinal Medical procedures at University of Texas Southwestern Medical School, Dallas; with the Division of Surgery, Veterans Affairs Medical Center Dallas; and in the Department of Bioengineering, University of Texas at Arlington.The study showed that the stent with the Dua anti-reflux valve remained useful for a median of 145 days compared to 90 days in those with a typical stent. This resulted in fewer repeat endoscopies for stent adjustments in individuals with the Dua stent. There have been six patients in the anti-reflux stent group in whom the stent remained patent for six months and longer compared to only one such patient in the typical stent group. In individuals with advanced cancers leading to bile duct obstruction in whom life span is limited, this difference might result in fewer procedures to keep bile duct patency. That means a better standard of living for these cancer sufferers, says Dr. Dua. Our next step is to do electron microscopic evaluation of clogged standard and anti-reflux stents to judge the role of reflux of intestinal contents in stent clogging, Dua says.