During the first eight months of this year, fewer than 18 percent of Medicare patients ended up back in the hospital within a month of discharge, the lowest rate in years, the government reported Friday. This drop occurred during the first year that Medicare financially penalized hospitals for their readmission rates, and the government seized on the decrease as evidence the incentives are having an effect. The government is targeting rehospitalizations as a significant indicator of gaps in medical quality in the nation's hospitals.