title: Pre-polysomnographic assessment using the Pittsburgh Sleep Quality Index questionnaire is not useful in identifying people at higher risk for obstructive sleep apnea.
abstract: BACKGROUND
  Polysomnography remains the diagnostic gold standard for obstructive sleep apnea syndrome (OSAS), but it is time consuming and requires dedicated personnel and setting. It may be more useful to plan a polysomnogram based on a preliminary screening.
  
  
  OBJECTIVE
  To verify whether a questionnaire of general quality of sleep, the Pittsburgh Sleep Quality Index (PSQI), could outperform a dedicated questionnaire (Epworth Sleep Scale: ESS) in targeting OSAS patients in an at risk population.
  
  
  METHODS
  254 consecutive subjects attending the outpatient clinic for respiratory diseases were clinically evaluated for sleep apnea and referred to a 12 channel night-time polysomnography. All patients were administered the ESS and the PSQI before the procedure. The correlation between the Apnoea/Hypopnoea Index (AHI) and the global score of the PSQI was calculated; Sensitivity, specificity, positive and negative predictive values (PPV and NPV, respectively), Diagnostic accuracy and the area under the receiver operating characteristic curve (AUC) were calculated. ESS performance was used as a control reference.
  
  
  RESULTS
  The mean age was 65.8 (standard deviation: 12.1) and the study group was 68.4% male. The mean BMI was 38.5; SD 7.7. Prevalence of OSAS in the study population was 55.5%; OSAS was severe in 60.5% of OSAS patients. ESS was significantly, but weakly, correlated with the AHI (AHI vs ESS: R = 0.308; p < 0.001), whereas PSQI was not (R = 0.037; p = 0.581). Both PSQI and ESS, however, performed unsatisfactorily: sensitivity 37.8% and 69.7%; Specificity 76.1% and 31.0%; Diagnostic Accuracy 57.5% and 49.8%; PPV 60% and 48.7%; NPV 56.3% and 52.2%; AUC 0.589 and 0.509, respectively.
  
  
  CONCLUSIONS
  The PSQI score is not helpful in the pre-polysomnographic assessment of people with suspected OSAS. Further studies are required to provide reliable pre-clinical instruments targeting patients amenable to polysomnography.
authors.affiliation: Geriatrics - Unit of Respiratory Pathophysiology - Campus Bio Medico University and Teaching Hospital, Rome - Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Scarlata
authors.forename: Claudio
authors.initials: C
authors.lastname: Pedone
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Curcio
authors.forename: Livio
authors.initials: L
authors.lastname: Cortese
authors.forename: Domenica
authors.initials: D
authors.lastname: Chiurco
authors.forename: Davide
authors.initials: D
authors.lastname: Fontana
authors.forename: Mariangela
authors.initials: M
authors.lastname: Calabrese
authors.forename: Riccardina
authors.initials: R
authors.lastname: Fusiello
authors.forename: Gloria
authors.initials: G
authors.lastname: Abbruzzese
authors.forename: Simona
authors.initials: S
authors.lastname: Santangelo
authors.forename: Anna
authors.initials: A
authors.lastname: Zito
authors.forename: Raffaele Antonelli
authors.initials: RA
authors.lastname: Incalzi
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000706:statistics & numerical data*; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis*; D011795:Surveys and Questionnaires
keywords: Obstructive Sleep Apnea; polysomnography; risk assessment; screening; sleep quality