P3‐297: what will i be like next year? impact of frontotemporal disorder phenotype on loss of functional independence

Some studies suggest that patients with behavioral-variant FTD (bvFTD) experience a more rapid rate of functional decline than patients with Alzheimer's disease (AD), while patients with semantic-variant primary progressive aphasia (PPA-S) may experience a slower rate of functional decline than patients with bvFTD (O'Connor & Mioshi, 2016). However, there is a dearth of research comparing functional decline between other FTD phenotypes, despite the fact that information about expected functional decline can inform conversations about financial and legal planning between families, patients, and providers. This study aims to fill this gap. We included a sample of 202 people with mild FTD spectrum disorders from the National Alzheimer's Coordinating Center (NACC) and analyzed change in the Functional Activities Questionnaire (FAQ) over 1 year. Participants had a global CDR of 1 or less, a baseline FAQ score of 15 or less, and no other confounding diagnoses. We hypothesized that functional decline would be fastest in PSP followed by bvFTD, CBD, PPA-G, and PPA-S. Contrary to our hypothesis, we found the following change in FAQ over one year in the following groups: CBD (M=7.9, SD=6.0), bvFTD (M=7.9, SD=6.6), PPA-S (M=7.2, SD=6.2), PSP (M=6.4, SD=7.4), and PPA-G (M=4.6, SD=6.6). Multiple regression models that included diagnosis, years of education, age, and baseline FAQ, demonstrated that patients with PPA-G exhibited slower functional decline than the bvFTD and PPA-S groups. Years of education, age, and baseline FAQ were not significant predictors in the model. Further analyses will examine the interaction between age and diagnosis. Patients with AD will be added as a comparison group. Patients and families often ask providers for advice about major life decisions based on expected functional decline. Our findings suggest that these conversations can be informed by the FTD phenotype. We hope that our findings will contribute to a growing body of literature that supports providers, patients, and families with concrete information about prognosis. References: O'Connor, C. M., & Mioshi, E. (2016). Functional disability and the impact of frontotemporal dementia in everyday life. In B. C. Dickerson (Ed.), Hodges’ frontotemporal dementia (pp. 211-228). Cambridge University Press, Cambridge, United Kingdom.