Patients with mild cognitive impairment (MCI) and their caregivers are concerned with the likelihood and time course of progression to dementia. This study was performed to identify the clinical predictors of the MCI progression in a Korean registry, and investigated the effects of medications without evidence, frequently prescribed in clinical practice.

Using a Korean cohort that included older adults with MCI who completed at least one follow-up visit, clinical characteristics and total medical expenses including prescribed medications were compared between two groups: progressed to dementia or not. Cox proportional hazards regression analysis was conducted.

During the mean 1.42±0.72 years, 215 (27.63%) of 778 participants progressed to dementia. The best predictors were age [hazard ratio (HR), 1.036; 95% confidence interval (CI), 1.006–1.067; p =0.018], apolipoprotein ε4 allele (HR, 2.247; 95% CI, 1.512–3.337; p <0.001), Clinical Dementia Rating scale-sum of boxes scores (HR, 1.367; 95% CI, 1.143–1.636; p =0.001), Instrumental Activities of Daily Living scores (HR, 1.035; 95% CI, 1.003–1.067; p =0.029), and lower Mini-Mental State Examination scores (HR, 0.892; 95% CI, 0.839–0.949; p <0.001). Total medical expenses were not different.

Our data are in accordance with previous reports about clinical predictors for the progression from MCI to dementia. Total medical expenses were not different between groups with and without progression.