The New Satisfaction with Life and Treatment Scale (SLTS-7) in Patients with Parkinson’s Disease

Background: The satisfaction with life and, in particular, with treatment in Parkinson’s disease (PD) is understudied. Objective: To explore a new 7-item rating tool assessing satisfaction with life and treatment (SLTS-7) in PD. Methods: In this cross-sectional, multi-center study, including patients screened for advanced therapies, psychometric characteristics of the SLTS-7 were analyzed. An exploratory factor analysis identified the underlying factorial structure of the SLTS-7. Results: 117 patients were included, and the data quality of the SLTS-7 was excellent (computable data 100%), and acceptability measures satisfied standard criteria. Besides the global assessment (item 1), the exploratory factor analysis produced item 2 (physical satisfaction) as an independent item and two factors among the remaining items: items 3–5 (psycho-social satisfaction), and items 6 and 7 (treatment satisfaction). Cronbach’s alpha was 0.89, indicative of high internal consistency. The SLTS-7 total score correlated moderately with motor symptoms and weakly with non-motor symptoms total scores. SLTS-7 showed the highest correlations with the European Quality of Life with 5 items (EQ-5D) visual analog scale (0.43–0.58, p