Although artificial intelligence is in its early stages in the health-care industry, it already has triggered legal action. A class-action lawsuit filed on Tuesday alleges that UnitedHealthcare used an artificial intelligence algorithm to wrongfully deny coverage under Medicare Advantage health policies. The insurer made health-care determinations using its nH Predict algorithm, overrode physician recommendations, and denied elderly patients’ claims for stays in extended-care facilities, according to the lawsuit in the U.S. District Court for the District of Minnesota. The plaintiffs also alleged the technology lets the company “aggressively deny coverage, because they know they will not be held accountable for...