The Pittsburgh Sleep Quality Index (PSQI): Psychometric and Clinical Risk Score Applications Among College Students

Sleep is closely related to physical andmental health problems as well as problem behaviors among adolescents and young adults. Thus, to better understand sleep seems paramount, including how to best measure it. The Pittsburgh Sleep Quality Index (PSQI) is one of the most widely used sleep measures. Some recent psychometric evidence (i.e., inconsistent dimensionality across studies) has called into question the application of this clinically developed measure. The current study sought to rigorously test the dimensionality of the measure, by comparing a psychometric application of it to a clinical application. It also tested correlates of sleep quality measured by the PSQI, including academic achievement, mental health, and substance use (alcohol and drug use). Data were collected from 820 college students using an online computer-assisted protocol. Results from factor analyses supported a 2-factor solution for the PSQI. Findings from path analyses using scale scores based on the extracted factor structure as the independent variable provided evidence that the psychometric approach worked equally well as the clinical application using the global sleep quality risk score, providing some support for the use of a psychometric approach of the PSQI. Sleep quality scores (both scale and global sleep quality risk scores)were consistently associatedwith academic achievement,mental health, and substance use problems, thus providing further support on the importance of good sleep for young adults.