Association between Subjective Cognitive Complaints and Incident Functional Impairment in Parkinson's Disease

Abstract Background Early identification of subjective cognitive complaints (SCC) in Parkinson's disease (PD) may improve patient care if it predicts cognition‐related functional impairment (CFI). Objectives The aim was to determine the cross‐sectional and longitudinal association between SCC and CFI in PD. Methods Data were obtained from Fox Insight, an online longitudinal study that collects PD patient‐reported outcomes. Participants completed a PD Patient Report of Problems that asked participants for their five most bothersome disease problems. SCCs were placed into eight categories through human‐in‐the‐loop curation and classification. CFI had a Penn Parkinson's Daily Activities Questionnaire (PDAQ‐15) score ≤49. Cox proportional hazards models and Kaplan–Meier survival analyses determined if baseline SCC was associated with incident CFI. Results The PD‐PROP cohort (N = 21,160) was 55.8% male, mean age was 65.9 years, and PD duration was 4.8 years. At baseline, 31.9% (N = 6750) of participants reported one or more SCCs among their five most bothersome problems, including memory (13.2%), language/word finding (12.5%), and concentration/attention (9.6%). CFI occurred in 34.7% (N = 7332) of participants. At baseline, SCC was associated with CFI ( P ‐value <0.001). SCC at baseline was associated with incident CFI (hazard ratio [HR] = 1.58 [95% confidence interval: 1.45, 1.72], P ‐value <0.001), as did cognitive impairment not otherwise specified (HR = 2.31), executive abilities (HR = 1.97), memory (HR = 1.85), and cognitive slowing (HR = 1.77) ( P ‐values <0.001). Kaplan–Meier curves showed that by year 3 an estimated 45% of participants with any SCC at baseline developed new‐onset CFI. Conclusions Self‐reported bothersome cognitive complaints are associated with new‐onset CFI in PD. Remote electronic assessment can facilitate widespread use of patient self‐report at population scale. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.