Self-Reported Sleep Quality Using the Malay Version of the Pittsburgh Sleep Quality Index (PSQI-M) In Malaysian...

(1) Background: The Pittsburgh Sleep Quality Index (PSQI) is a useful tool for the assessment of subjective sleep quality in non-clinical and clinical settings. This study aimed to determine sleep quality in a general Malaysian adult population using a validated Malay version of the Pittsburgh sleep quality index (PSQI-M); (2) Methods: The original PSQI was translated into Malay following forward and backward translation guidelines. The final Malay version was administered to a sample of healthy working adults (n = 106; mean age: 35.3 ± 7.6 years) without history of sleep disorders. Reliability and agreement were assessed using Cronbach's alpha, intra-class correlations coefficient (ICC), standard error of measurement (SEM), and Bland-Altman plot. Convergent validity of PSQI-M was examined with the Malay version of Epworth sleepiness scale (ESS-M) using Pearson's correlation coefficient; (3) Results: Overall mean PSQI global score was 5.25 ± 1.85. About 45% of the sample had PSQI global score >5, indicating poor sleep quality. Total sleep duration per night was 5.95 ± 1.05 h, below the recommended amount. Sleep quality seems to be affected by age but not gender. Internal consistency as measured by Cronbach's alpha in the whole sample was 0.74, with test-retest reliability (ICC) of 0.58 and SEM of 1.34. The PSQI test-retest scores indicated that most of the respondents (90%) lay within the 95% limits of agreement. The PSQI-M also showed significant correlation with ESS-M scores (r = 0.37, p < 0.01); (4) Conclusion: The PSQI-M showed acceptable reliability and is valid to be used in a general Malaysian adult population. Findings also indicate that a majority of the adults in our sample were experiencing inadequate sleep, thus further research is needed to identify the factors associated with poor sleep quality.