The reliability and validity of the Korean version of the Pittsburgh Sleep Quality Index

PurposeThe Pittsburgh Sleep Quality Index (PSQI) is a self-reported questionnaire that measures sleep quality during the previous month. The aims of this study were to analyze the reliability and validity of the Korean version of the PSQI (PSQI-K) and to evaluate its usefulness.MethodsWe developed the PSQI-K, which involved translating the original PSQI into Korean and then translating back into English to check its accuracy. We tested the validity of the PSQI-K on a total of 394 individuals: 261 with poor sleep (primary insomnia, n = 211; narcolepsy, n = 50) and 133 with good sleep. All subjects completed the PSQI-K, 285 had overnight nocturnal polysomnography, and 53 were randomly selected for a retest with the questionnaire after 2–4 weeks without any intervening treatment. The mean PSQI-K global scores in each group were analyzed after adjusting for age and sex.ResultsCronbach's α coefficient for internal consistency of the total score of the PSQI-K was 0.84 which shows high reliability. Sensitivity and specificity for distinguishing poor and good sleepers were 0.943 and 0.844 using the best cutoff point of 8.5. The total and component scores of the PSQI-K for insomnia and narcolepsy were significantly higher than those for controls (p < 0.05). The test–retest correlation coefficient was 0.65 for the total score (p < 0.001). There was no significant difference between the two values using the paired t tests.ConclusionsThe PSQI-K is a reliable and valid questionnaire for evaluating sleep quality in patients with sleep disorders.

[1]  M Jinks,et al.  Insomnia and its treatment. , 1976, Journal of the American Pharmaceutical Association.

[2]  E. C. Hammond,et al.  Short and long sleep and sleeping pills. Is increased mortality associated? , 1979, Archives of general psychiatry.

[3]  R. Malcolm,et al.  Insomnia and its treatment. When are hypnotics justified? , 1984, Postgraduate medicine.

[4]  E. Uhlenhuth,et al.  Insomnia and its treatment. Prevalence and correlates. , 1985, Archives of general psychiatry.

[5]  Daniel J Buysse,et al.  The Pittsburgh sleep quality index: A new instrument for psychiatric practice and research , 1989, Psychiatry Research.

[6]  Daniel J Buysse,et al.  Quantification of subjective sleep quality in healthy elderly men and women using the Pittsburgh Sleep Quality Index (PSQI) , 1991, Sleep.

[7]  R. Daroff,et al.  The International Classification of Sleep Disorders , 1991, Neurology.

[8]  Daniel J Buysse,et al.  A longitudinal study of laboratory- and diary-based sleep measures in healthy "old old" and "young old" volunteers. , 1994, Sleep.

[9]  L. Sheely.  Sleep disturbances in hospitalized patients with cancer. , 1996, Oncology nursing forum.

[10]  Sheely Lc.  Sleep disturbances in hospitalized patients with cancer. , 1996 .

[11]  J. Pilcher,et al.  Sleep quality versus sleep quantity: relationships between sleep and measures of health, well-being and sleepiness in college students. , 1997, Journal of psychosomatic research.

[12]  M. Andrykowski,et al.  Psychometric evaluation of the Pittsburgh Sleep Quality Index. , 1998, Journal of psychosomatic research.

[13]  Makoto Uchiyama,et al.  Psychometric assessment of subjective sleep quality using the Japanese version of the Pittsburgh Sleep Quality Index (PSQI-J) in psychiatric disordered and control subjects , 2000, Psychiatry Research.

[14]  C. Morin,et al.  Validation of the Insomnia Severity Index as an outcome measure for insomnia research. , 2001, Sleep medicine.

[15]  K. Junghanns,et al.  Test-retest reliability and validity of the Pittsburgh Sleep Quality Index in primary insomnia. , 2002, Journal of psychosomatic research.

[16]  A. Barsevick,et al.  Psychometric evaluation of the Pittsburgh Sleep Quality Index in cancer patients. , 2004, Journal of pain and symptom management.

[17]  Chun-Jen Huang,et al.  Psychometric Evaluation of the Chinese Version of the Pittsburgh Sleep Quality Index (CPSQI) in Primary Insomnia and Control Subjects , 2005, Quality of Life Research.

[18]  Daniel J Buysse,et al.  Validation of a 3-factor scoring model for the Pittsburgh sleep quality index in older adults. , 2006, Sleep.

[19]  A. Oksenberg,et al.  Validation of the Pittsburgh Sleep Quality Index Hebrew translation (PSQI-H) in a sleep clinic sample. , 2007, The Israel Medical Association journal : IMAJ.

[20]  A. Adewuya,et al.  Validity of the Pittsburgh Sleep Quality Index (PSQI) among Nigerian university students. , 2007, Sleep medicine.

[21]  Donald M Hilty,et al.  Sleep in hospitalized medical patients, part 1: factors affecting sleep. , 2008, Journal of hospital medicine.

[22]  B. Garrusi,et al.  Psychometric properties of the Persian version of the Pittsburgh Sleep Quality Index addendum for PTSD (PSQI-A) , 2009, Sleep and Breathing.

[23]  M. Sateia.  Update on sleep and psychiatric disorders. , 2009, Chest.

[24]  Y. Cho,et al.  The reliability and validity of the Korean version of the Epworth sleepiness scale , 2011, Sleep and Breathing.

[25]  B. Yates,et al.  Translating the Pittsburgh Sleep Quality Index Into Arabic , 2010, Western journal of nursing research.

[26]  S. Fagondes,et al.  Validation of the Brazilian Portuguese version of the Pittsburgh Sleep Quality Index. , 2011, Sleep medicine.