Evaluation of sleep quality in individuals with Parkinson’s disease using objective and subjective measures

The aim of this study is to investigate sleep quality in Parkinson’s disease (PD) and to correlate subjective measures, through clinical scales and sleep diary, with objective measures obtained by means of actigraphy. In this prospective comparative study, the population consisted of PD patients with a moderate stage of the disease, who were evaluated by subjective scales such as the Pittsburgh Sleep Quality Index—PSQI, Epworth Sleepiness Scale—ESS, Parkinson’s Disease Sleep Scale—PDSS and by sleep diary, besides objective measures from actigraphy recording over seven consecutive days. Participants were categorized into two groups: “good sleep” = PDSS > 100 and “poor sleep” = PDSS ≤ 100. In total, 48 individuals were evaluated, and the overall median (inter-quartile range) was 68 (55–70) for years of age, 95.3 (73.1–111.8) for PDSS, 8 (5–11) for PSQI. Twenty-eight (58.3%) participants had poor sleep quality according to the PDSS. Poor sleep quality was associated with higher depression score (p = 0.01) and with living without partner (p = 0.04). A significant difference was observed in all items of PDSS, except in the item daytime dozing (p = 0,10). Actigraphy—and sleep diary-based parameters did not vary according to the sleep quality measured with the PDSS. In general, subjective and objective sleep parameters presented weak to moderate correlation, except for sleep latency and sleep efficiency. Sleep quality is impaired in PD when assessed by actigraphy, clinical sleep scales and sleep diary. Parameters measured objectively should not be replaced by subjective parameters and vice versa due to the complexity of individual’s perception about sleep.