Validity of the Short Weekly Calendar Planning Activity in patients with Parkinson disease and nonmanifesting LRRK2 and GBA carriers

Abstract Background and purpose Subtle executive dysfunction is common in people newly diagnosed with Parkinson disease (PD), even when general cognitive abilities are intact. This study examined the Short Weekly Calendar Planning Activity (WCPA‐10)'s known‐group construct validity, comparing persons with PD to healthy controls (HCs) and nonmanifesting carriers of LRRK2 and GBA gene mutations to HCs. Additionally, convergent and ecological validity was examined. Methods The study included 73 participants: 22 with idiopathic PD (iPD) who do not carry any of the founder GBA mutations or LRRK2 ‐G2019S, 29 nonmanifesting carriers of the G2019S‐ LRRK2 ( n = 14) and GBA ( n = 15) mutations, and 22 HCs. Known‐group validity was determined using the WCPA‐10, convergent validity by also using the Montreal Cognitive Assessment (MoCA) and Color Trails Test (CTT), and ecological validity by using the WCPA‐10, Schwab and England Activities of Daily Living Scale (SE ADL), and Physical Activity Scale for the Elderly (PASE). Results Known‐group validity of the WCPA‐10 was established for the iPD group only; they followed fewer rules ( p = 0.020), were slower ( p = 0.003) and less efficient ( p = 0.001), used more strategies ( p = 0.017) on the WCPA‐10, and achieved significantly lower CTT scores ( p < 0.001) than the HCs. The nonmanifesting carriers and HCs were similar on all cognitive tests. Convergent and ecological validity of the WCPA‐10 were partially established, with few correlations between WCPA‐10 outcome measures and the MoCA ( r = 0.50, r = 0.41), CTT‐2 ( r = 0.43), SE ADL ( r = 0.41), and PASE ( r = 0.54, r = 0.46, r = 0.31). Conclusions This study affirms the known‐group validity for most (four) WCPA‐10 scores and partially confirms its convergent and ecological validity for PD.