Reliability and validity of the Thai version of the Pittsburgh Sleep Quality Index.
OBJECTIVE
To assess the internal consistency, test-retest reliability, and validity of the Thai version of the Pittsburgh Sleep Quality Index (Thai-PSQI), which was recently translated using a standardized method, in Thai patients with major sleep disorders.


METHODS
The Thai-PSQI was developed under a standard translation protocol and administered to "bad" sleepers (i.e. patients with suspected obstructive sleep apnea [OSA], depression, or insomnia) and "good" sleepers in an academic tertiary care setting. All participants were asked to complete the same questionnaire after 2-4 weeks.


RESULTS
A total of 138 participants consisting of 69 patients with OSA, 28 with major depression, 11 with primary insomnia, and 30 controls completed the questionnaire. The global scores of the Thai-PSQI revealed that it had excellent internal consistency (Cronbach's alpha = 0.837) and test-retest reliability (intraclass correlation coefficient = 0.89). An analysis of covariance demonstrated a significant difference in Thai-PSQI global score between good sleepers and bad sleepers (p < 0.001). A cut-off point of 5 out of 6 on the global score resulted in a sensitivity of 77.78% and specificity of 93.33%.


CONCLUSIONS
The Thai-PSQI is a valid and reliable tool for screening and identifying the presence of significant sleep disturbances, and is comparable to the original English version.
Tullaya
T
Sitasuwan
Sontuss
S
Bussaratid
Pimon
P
Ruttanaumpawan
Wattanachai
W
Chotinaiwattarakul
D000328:Adult; D000368:Aged; D003431:Cross-Cultural Comparison; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D015203:Reproducibility of Results; D012891:Sleep Apnea Syndromes / Q000175:diagnosis*; D011795:Surveys and Questionnaires; D013785:Thailand