Progression to dementia in probable and possible mild cognitive impairment

Lopez and colleagues reported the results of the Cardiovascular Health Study Cognition Study (CHS-CS) of Pittsburgh, Pennsylvania, in which 136 subjects with mild cognitive impairment (MCI) were subclassified as “possible” when there were comorbidities that could explain the subjects' cognitive deficits and as “probable” when there were none. Furthermore, the CHS-CS did not require intact instrumental activities of daily living (IADL) for the diagnosis of MCI. The authors reported that the progression to dementia was slightly higher in subjects with probable MCI (181/1000 person-years) than in those with possible MCI (129/1000 person-years). The progression to dementia in the whole MCI sample was 147 of 1000 person-years.