Identifying and Characterizing Trajectories of Cognitive Change in Older Persons with Mild Cognitive Impairment

Abstract

Background: Mild cognitive impairment (MCI) represents a state of high risk for dementia but is heterogeneous in its course. To date, the trajectories reflecting distinct developmental courses of cognition among patients with MCI have not been well defined. Aim: To identify the developmental trajectory of groups with distinct cognitive change patterns among a cohort of MCI patients. Methods: 187 MCI patients from 2 geriatric outpatient clinics were evaluated serially with the Mini-Mental State Examination (MMSE) for up to 3.5 years. Group-based trajectory analysis was applied to identify distinct trajectories. Estimates of decline for each group were compared with the mean rate of decline obtained from mixed modeling of the entire sample. Results: 5 trajectories were identified and labeled based on their baseline MMSE score and course: (1) 29/stable (6.5%); (2) 27/stable (53.9%); (3) 25/slow decline (23.8%); (4) 24/slow decline (11.6%); (5) 25/rapid decline (4.2%). Annual rate of change in the MMSE score for these 5 groups was 0.09, –0.43, –1.23, –1.84, and –4.6 points, respectively. None corresponded to the mean rate of –0.82 points estimated for the group as a whole. A majority of MCI patients (60.4%) follow stable cognitive trajectories over time. Within the 3 groups with declining trajectories, cognitive decline occurs slowly in a vast majority of MCI patients (98.5%). Conclusions: Results provide direct evidence for the heterogeneous course of cognitive decline that has been suggested by the variable prognosis for patients with MCI.

Predictors of Future Cognitive Decline in Persons with Mild Cognitive Impairment

“…The sample for this study was identical to that examined in our previous study for which trajectories of cognitive change were identified [26]. Of 311 MCI patients, a total of 187 patients who had been administered the MMSE at their initial visit to the clinic and at least once more over a period of up to 3.5 years were included.…”

“…Of 311 MCI patients, a total of 187 patients who had been administered the MMSE at their initial visit to the clinic and at least once more over a period of up to 3.5 years were included. This subgroup did not differ by age, sex, education, language, or baseline MMSE score from the 124 who were not administered the MMSE at their initial visit or who had the MMSE only once [26]. The average number of MMSE administrations for included patients was 4 (±1.7; range 2–9).…”

“…In our previous work using a group-based trajectory modeling approach [28,29], we provided empirical evidence for the existence of five distinct trajectories of cognitive change as measured by the MMSE total score, among a clinic sample of people with MCI who were followed for up to 3.5 years (fig. 1) [26]. In this cohort, some patients remained stable or even reverted to normal, and others declined with different initial MMSE total scores and rates of cognitive change.…”

“…The identification of such persons is arguably as important as identifying those who will convert to dementia over a specified period of time, to the extent that continued decline may be expected beyond the follow-up period of a study. Demographic variables such as older age have been associated with a greater rate of decline in MMSE score among people with MCI [26]; however, little is known about clinical predictors of change in cognitive ability. In a study of 505 elderly nursing home residents, orientation to time was found to predict subsequent decline in the total MMSE score [27].…”

P3‐160: Empirically Defining Trajectories of Late‐life Cognitive and Functional Decline

“…Xie and colleagues [16] used groupbased trajectory analysis to identify distinct cognitive change patterns among a cohort of 187 MCI patients from two geriatric outpatient clinics over a course of up to 3.5 years. Five trajectories were identified and labeled based on their baseline MMSE score.…”