Use of a personal digital assistant led to greater achievement of functional memory goals ( mean difference 1.6 ( 95 % confidence interval ( CI ) 1.0 to 2.2 ) , P = 0.0001 ) and improvement on the General Frequency of Forgetting subscale ( mean difference 12.5 ( 95 % CI 2.0 to 22.9 ) , P = 0.021 ) .