Predicting the Course of Mild Cognitive Impairment in a Memory Disorder Clinic Sample

Abstract

Objective: The present study examines a number of psychosocial and medical risk factors for dementia and their association with the outcome of mild cognitive impairment (MCI) in a memory disorder clinic sample. Method: Twelve years of archival cognitive testing data from 125 East Central Florida Memory Disorder Clinic patients was utilized. Participants were included in this study if they were diagnosed with MCI following initial cognitive testing and then re-evaluated and diagnosed with either stable MCI, dementia of the Alzheimer’s type (AD) or mixed dementia (dementia of the Alzheimer’s type and vascular dementia), or cognition within normal limits. Patients’ medical and psychosocial information was obtained from their electronic medical records (EMR) and included as predictors in this present study. Results: Age of patients (M = 77.2, SD = 6.2) at initial visit was associated with an increase in the odds of receiving a final diagnosis of dementia, with an odds ratio of 1.074 (95% CI, 1.014 to 1.137), Wald, χ2 (1) = 5.893, p = .015. Individuals who were diagnosed with amnestic MCI at their initial evaluation were more likely to convert to dementia (χ 2 (18) = 45.65, p < .001). A history of depression was also associated with an increase in the odds of receiving a final diagnosis of dementia, with an odds ratio of 3.213 (95% CI, 1.200 to 8.605), Wald, χ2 (1) = 5.396, p = .020. The odds of receiving a final diagnosis of dementia were also significantly higher for patients who had a diagnosis of hypertension, with an odds ratio of 2.771 (95% CI, 1.240 to 6.197), Wald , χ2 (1) = 6.166, p = .013. Additionally, patients with a history of comorbid depression and hypertension had increased odds of converting to dementia, with an odds ratio of 8.894 (95% CI, 3.564 to 22.192), Wald, χ2 (1) = 21.942, p = < .001. In contrast, patients with a history of age-related macular degeneration had increased odds of remaining stable MCI, with an odds ratio of 4.762 (95% CI, 1.115 to 20.333), Wald, χ2 (1) = 4.440, p = .035. Conclusion: The results of the present study support previous literature that suggests advancing age is the largest non-modifiable risk factor for dementia. Prior research suggesting amnestic MCI patients are more likely to convert to dementia was also supported. The present study’s findings also suggest that patients with MCI may be more likely to progress to AD if they have histories of depression and/or hypertension. This supports previous research that suggests a relationship between cardiovascular risk factors and mental health conditions such as depression, with future cognitive impairment. This highlights the importance of treating modifiable risk factors for dementia, particularly depression and hypertension, in order to delay the onset of AD in patients who have MCI. Lastly, the results of this study may assist clinicians in determining which patients with MCI may be most likely to convert to dementia, with older patients who have amnestic MCI, depression, and hypertension, being the most likely to convert.