To assess the reliability and validity concerning the formal European Portuguese version of the Pittsburgh Sleep Quality Index [PSQI (EP)], its accuracy, and optimal cut-off point. N = 564 volunteers (18–80 years old) recruited in several settings (e.g., university campuses; work place; home; sleep consultations), agreed to complete the PSQI (EP). Subgroups completed additional measures: Insomnia Severity Index (ISI), STOP-Bang, Glasgow Sleep Effort Scale, or responded to a supplementary question about perceived sleep problems. As to internal consistency, Cronbach’s α = 0.75. Principal component analysis revealed a unidimensional structure. Six PSQI (EP) components and total scores were able to discriminate individuals who did versus did not describe having any sleep problem; all PSQI (EP) scores were significantly higher (denoting poorer quality) in participants suffering from a sleep disorder. Most Cohen’s d values showed large magnitude associations. PSQI (EP) and ISI scores were highly correlated, but no significant correlations were found considering STOP-Bang. ROC analysis confirmed an optimal cut-off point > 5 of the PSQI (EP) to detect self-reported poor/good sleepers in non-clinical settings. To discriminate non-clinical from clinical sleep patients, the optimal cutoff was > 7, and AUC = 0.94. The European Portuguese version of the PSQI performs as a reliable, valid, and accurate measure of overall sleep quality in Portuguese participants. Furthermore, results suggest that PSQI (EP) can discriminate poor sleepers in non-clinical settings, in addition to demonstrating high clinical accuracy in signaling potential sleep-disorder cases. In conclusion, the PSQI (EP) is a suitable tool to assess general sleep quality in Portuguese participants, both for clinical or non-clinical applications.
Sleep and Biological Rhythms – Springer Journals
Published: Jun 2, 2018
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera