Relevance of Coded Prodromal Mild Cognitive Impairment in the Routine Treatment of Patients with Dementia in Germany

Little is known about the impact of prior mild cognitive impairment (MCI, ICD-10: F06.7) diagnosis on the time to dementia diagnosis, anti-dementia drug therapy, and treatment persistence in patients with dementia (PWD). Patients with dementia diagnoses who started anti-dementia therapy between January 2010 and December 2016 were selected from 203 neurological/psychiatric practices in the Disease Analyzer databank (IQVIA). Patients with a history of MCI were compared to non-MCI controls in terms of demographic characteristics, anti-dementia therapy, and the rate of persistence with anti-dementia drugs. For persistence analyses, a 1: 1 matching procedure was used based on age, gender, type of residence, and depression and dementia diagnosis. Persistence was represented using Kaplan-Meier curves. A Cox regression analysis was used to determine the influence of MCI diagnosis on persistence with anti-dementia drugs. 339 PWD with MCI diagnoses and 339 controls were available for analysis. PWD with MCI were younger (78.9 versus 80.4 years), less likely to live in a nursing home (8.5% versus 22.5%), more frequently received donepezil (40.1% versus 33.7%), and more likely to exhibit comorbid depression (29.6% versus 16.9%). There was no association between the risk of treatment discontinuation and prior MCI diagnosis. After 24 months, 40% versus 41.1% of patients had discontinued treatment. The prior MCI diagnosis presumably led to an earlier diagnosis of dementia and earlier anti-dementia treatment. Treatment continuity did not differ, which would suggest that it does not depend on prior MCI diagnosis but on the behavior of patients and their caregiving relatives.