What's holding machine learning back in healthcare?

Healthcare is jam-packed with complex data stored in multiple places and evolving every day. That makes it a great target for the form of artificial intelligence known as machine learning. Oxford defines machine learning as "the use and development of computer systems that are able to learn and adapt without following explicit instructions, by using algorithms and statistical models to analyze and draw inferences from patterns in data." In recent years, machine learning already has proven useful in diagnosis and can help with the efficiency of medical coding. But there are many other places where machine learning can be useful but has yet to make headway.