Purpose: SCOPA-SLEEP is a rating scale for night-time sleep and daytime sleepiness (DS) proposed for use among people with Parkinson's disease (PD) as well as others. We translated it into Swedish and assessed its psychometric properties in PD and age-matched healthy controls.
Methods: Following translation according to the dual-panel approach, the Swedish SCOPA-SLEEP was field-tested regarding comprehensibility, relevance and respondent burden (n = 20). It was then psychometrically tested according to classical test theory (data completeness, scaling assumptions, targeting, reliability and construct validity) using data from 149 people with PD and 53 age-matched healthy controls from the prospective Swedish BioFINDER study.
Results: SCOPA-SLEEP took a mean of 3.5 min to complete and was considered easy to use and relevant. Missing item responses were <8 %, corrected item-total correlations were ≥0.47 (except for one DS item among controls), factor analyses suggested one dimension per scale, floor/ceiling effects were ≤17 %, reliability was ≥0.85 except for the DS scale among controls (0.65) and construct validity was supported.
Conclusions: Observations concur with previous evaluations, thus providing initial support for the Swedish SCOPA-SLEEP among people with PD. Further studies are needed to establish its generic properties and to understand its measurement properties in better detail.
Keywords: Parkinson’s disease; Rating scale; Reliability; Sleep; Translation; Validity.