A Validation Study of PROMIS Sleep Disturbance (PROMIS-SD) and Sleep Related Impairment (PROMIS-SRI) Item Banks in Individuals with Idiopathic Parkinson's Disease and Matched Controls.

BACKGROUND Parkinson's disease (PD) is associated with sleep disturbance (SD) and sleep-related impairment (SRI). Validation of self-report measures of these problems is needed in PD. The Patient-Reported Outcomes Measurement Information System (PROMIS) includes tools that assess these problems (PROMIS-SD and PROMIS-SRI, respectively). OBJECTIVE This study aimed to further validate these measures in individuals with PD and matched controls. METHODS Individuals with early-stage PD (n=50) and matched controls (n=48) completed measures of SD including the PROMIS-SD, Pittsburgh Sleep Quality Index (PSQI), and Insomnia Severity Index (ISI). They also completed measures of daytime impairment including the PROMIS-SRI, Epworth Sleepiness Scale, State-Trait Anxiety Inventory, Beck Depression Inventory 2nd edition, and Parkinson's Disease Questionnaire-39. Internal consistency for the PROMIS measures were assessed using Cronbach's α coefficient and item-total correlations in the total sample. Convergent and divergent validity of the PROMIS item banks were assessed using Spearman correlations. RESULTS The PROMIS item banks had excellent internal consistency (α>0.94). Supporting convergent validity, the PROMIS-SD had strong correlations with other measures of SD (ρ>0.70, for PSQI and ISI) and the PROMIS-SRI had moderate to strong correlations with all measures of daytime impairment (ρ=0.41-0.72). Supporting divergent validity within the PD group, the PROMIS-SD correlated more strongly with SRI than with the Parkinson's Disease Questionnaire total score, a metric of PD related impairment. CONCLUSION In middle-aged and older adults, with and without early-stage PD, the PROMIS-SD and PROMIS-SRI are reliable and valid measures of SD and SRI, respectively.