A state commission recommended yesterday that Massachusetts dramatically change how doctors and hospitals are paid, essentially putting providers on a budget as a way to control exploding healthcare costs and improve the quality of care. The 10-member commission, which includes key legislators and members of Governor Deval Patrick’s administration, voted unanimously to largely scrap the current system, in which insurers typically pay doctors and hospitals a negotiated fee for each individual procedure or visit. That arrangement is widely seen as leading to unneeded tests and procedures. Massachusetts would be the first state to adopt such a broad “global payment’’ system,...