CHICAGO — Wearing a Chicago Cubs cap, T-shirt and shorts, Dr. David Mayer finished a 7.2-mile morning walk from Northwestern University behind a group of supporters holding a “Patient Safety Movement” sign Saturday morning under the Wrigley Field marquee.Mayer, a Cubs season ticket holder who grew up in Chicago, is more than 1,000 miles since February into a walk to every Major League Baseball park and spring training fields, hoping to raise awareness about preventable deaths that occur in health-care settings.It’s a cause he has been advocating for two decades, noting preventable medical harm...
