A vast majority of physicians in Massachusetts say the fear of being sued is driving them to order unnecessary tests, procedures, referrals, and hospitalizations. The phenomenon is adding at least $1.4 billion to annual healthcare costs in the state, according to a study. The Massachusetts Medical Society reported that 83% of physicians surveyed said they have practiced so-called defensive medicine and that an average of 18%-28% of tests, procedures, referrals, and consultations, and 13% of hospitalizations, were ordered to avoid lawsuits.