During the 12-month follow-up , the mean number of potentially harmful medications decreased in the intervention wards [ -0.43 , 95 % confidence interval ( CI ) -0.71 to -0.15 ] but remained constant in the control wards ( +0.11 , 95 % CI -0.09 to +0.31 ) ( P = .004 , adjusted for age , sex , and comorbidities ) .