Abbott Laboratories ABT.N rose 4.2% after raising its full-year profit forecast on a rebound in COVID-19 test sales. By Devik Jain and Shreyashi Sanyal Oct 20 (Reuters) - U.S. stock indexes edged higher on Wednesday, helped by strong quarterly updates from healthcare companies including Anthem and Abbott, while worries remained about the impact of supply chain constraints and inflation on corporate earnings. "Investors are digesting earnings and the impact of supply chain disruptions on Corporate America," said Fiona Cincotta, senior financial markets analyst at City Index.