The interests of Merck & Co. Inc. and Geisinger Health System intersect enough that the pair announced on Monday a multiyear collaboration to improve the coordination of care and get patients to take prescribed medicine more regularly than they do now. Neither side offered financial specifics about up-front contributions or hoped-for revenue or savings. Mark Timney, Merck's president of global human health for the U.S. market, said in an interview that Merck would contribute millions of dollars in employee time and energy, but not product, meaning Geisinger doctors won't be obligated to write prescriptions for Merck drugs ahead of competitors.