title: Test-retest validity of Parkinson's disease sleep scale 2nd version (PDSS-2).
abstract: OBJECTIVE
  The aim of the present study was to measure the test-retest validity of Parkinson's Disease Sleep Scale 2nd version (PDSS-2) on PD patients with stable medication and motor symptoms over the period of 4 weeks.
  
  
  METHODS
  The subject population consisted of 92 PD patients. Besides PDSS-2, Unified PD rating scale, Montgomery-Asberg Depression Rating Scale and EQ-5D were assessed at baseline and 4 weeks later.
  
  
  RESULTS
  The total score of PDSS-2 decreased from 19.06 ± 10.78 points to 18.00 ± 9.34 points (p > 0.05). For the total score of PDSS-2 the Intra-class and Lin's Concordance Correlation Coefficients were 0.782 and 0.799. The average difference between the baseline and follow-up total PDSS-2 scores was -1.06 points with the 95% confidence interval of -7.96 and +5.84 points.
  
  
  CONCLUSIONS
  Our data supports that the items and the total score of PDSS-2 have acceptable test-retest reliability over a four week period on patients with stable PD symptoms and pharmacological therapy.
authors.affiliation: Doctoral School of Clinical Neuroscience, University of Pécs, Pécs, Hungary.
authors.forename: Krisztina
authors.initials: K
authors.lastname: Horváth
authors.affiliation: Department of Neurology, University of Pécs, Pécs, Hungary.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Aschermann
authors.affiliation: Department of Neurology, University of Pécs, Pécs, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Acs
authors.affiliation: Department of Neurology, University of Pécs, Pécs, Hungary.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Deli
authors.affiliation: Doctoral School of Clinical Neuroscience, University of Pécs, Pécs, Hungary.
authors.forename: József
authors.initials: J
authors.lastname: Janszky
authors.affiliation: Department of Neurology, University of Pécs, Pécs, Hungary.
authors.forename: Kázmér
authors.initials: K
authors.lastname: Karádi
authors.affiliation: Department of Neurology, University of Pécs, Pécs, Hungary.
authors.forename: Sámuel
authors.initials: S
authors.lastname: Komoly
authors.affiliation: Department of Neurology, University of Pécs, Pécs, Hungary.
authors.forename: Béla
authors.initials: B
authors.lastname: Faludi
authors.affiliation: Department of Neurology, University of Pécs, Pécs, Hungary.
authors.forename: Norbert
authors.initials: N
authors.lastname: Kovács
mesh_terms: D000368:Aged; D003863:Depression / Q000175:diagnosis / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications*; D011569:Psychiatric Status Rating Scales; D015203:Reproducibility of Results; D012893:Sleep Wake Disorders / Q000175:diagnosis* / Q000209:etiology*
keywords: Sleep; concordance; intraclass correlation coefficient; scale