Reliability and validity of PSQI among frontline health care workers of COVID-19 using classical test theory and item response theory.

Wang, Ling; Wu, Yong-Xi; Lin, Yi-Qi; Wang, Lin; Zeng, Zhao-Nan; Xie, Xiao-Liang; Chen, Qiu-Yang; Wei, Shi-Chao

STUDY OBJECTIVES The applicability of sleep-related scale in frontline medical staff of COVID-19 epidemic has not been fully proved, so the sleep survey results lack credibility and accuracy, which brings difficulties to the guidance and treatment of frontline medical staff with sleep disorders, and is not conducive to the prevention and control of COVID-19 epidemic. This study sought to analyze the reliability and validity of the Pittsburgh Sleep Quality Index (PSQI) among the frontline medical staff fighting against COVID-19 epidemic. METHODS A network questionnaire survey was used to investigate PSQI among frontline medical staff who fought against COVID-19 in Wuhan from March 19 to April 15, 2020. Combined with classical test theory (CTT) and item response theory (IRT), the content validity, internal consistency, construct validity and others of PSQI were evaluated. RESULTS According to CTT, content validity, criterion validity, and construct validity of PSQI was good. But the internal consistency was better after the deletion of "daytime dysfunction" subscale. As for IRT, difficulty, differential item function and wright map performed well. CONCLUSIONS The original PSQI showed acceptable applicability in frontline anti-epidemic medical staff, and its characteristics moderately improved after "daytime dysfunction" subscale was removed.