Reliability, Validity, and Factor Structure of Pittsburgh Sleep Quality Index in Community-Based Centenarians

Chi Zhang; Hao Zhang; Minghao Zhao; Zhongquan Li; Chad E Cook; Daniel J Buysse; Yali Zhao; Yao Yao

doi:10.3389/fpsyt.2020.573530

Reliability, Validity, and Factor Structure of Pittsburgh Sleep Quality Index in Community-Based Centenarians

Front Psychiatry. 2020 Aug 31:11:573530. doi: 10.3389/fpsyt.2020.573530. eCollection 2020.

Authors

Chi Zhang^{1

2}, Hao Zhang³, Minghao Zhao⁴, Zhongquan Li⁵, Chad E Cook⁶, Daniel J Buysse⁷, Yali Zhao⁸, Yao Yao^{9

10}

Affiliations

¹ Department of Education, Beijing Hospital, National Center of Gerontology, Beijing, China.
² Institute of Geriatrics Medicine, Chinese Academy of Medical Sciences, Beijing, China.
³ Department of Healthcare Policy and Research, Weill Cornell Medicine, New York, NY, United States.
⁴ School of Basic Medicine, Peking University Health Science Center, Beijing, China.
⁵ School of Social and Behavioral Sciences, Nanjing University, Nanjing, China.
⁶ Department of Orthopaedics, Medical School of Duke University, Durham, NC, United States.
⁷ Psychiatry and Clinical and Translational Science, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States.
⁸ Central Laboratory, Hainan Hospital of Chinese PLA General Hospital, Sanya, China.
⁹ Center for Healthy Aging and Development Studies, National School of Development, Peking University, Beijing, China.
¹⁰ Center for the Study of Aging and Human Development and Geriatrics Division, Medical School of Duke University, Durham, NC, United States.

Abstract

Background: The Pittsburgh Sleep Quality Index (PSQI) is a widely used self-report questionnaire that measures general sleep quality in general populations. However, its psychometric properties have yet to be thoroughly examined in longevous persons.

Objectives: This study aimed to explore the reliability, validity and factor structure of the Chinese-language version of the PSQI in community-dwelling centenarians.

Methods: A total of 958 centenarians (mean age = 102.8 years; 81.8% females) recruited from 18 regions in Hainan, China, completed the PSQI scale. Cronbach's alpha coefficient was used to measure the internal consistency. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were performed to explore the validity and factor structure of the PSQI in this sample. Correlations between the global PSQI score and physical function, depression symptoms, self-reported health status and subjective well-being were used to assess divergent validity.

Results: The Cronbach's α coefficient of the PSQI was 0.68, and it increased to 0.78 after two components (medication use and daytime dysfunction) were removed. The Spearman correlation coefficients of the PSQI score with each component were statistically significant (P<0.01). EFA yielded a two-factor structure model of the original PSQI-7 and a one-factor structure model of the simplified PSQI-5. The one-factor model with five components (χ²/df =1.59, CFI=0.99, RMSEA=0.03) fit the data well and had good configural invariance across demographic characteristics (0.53<_Δχ²<5.58, P>0.05).

Conclusions: The original PSQI showed acceptable applicability in Chinese community-dwelling centenarians, and its psychometric characteristics moderately improved after sleeping medication and daytime dysfunction were removed. Further validation studies on PSQI are needed among centenarians from varied backgrounds.

Keywords: Pittsburgh Sleep Quality Index; centenarians; factor analysis; reliability; validity.