Validation of a 3-Factor scoring model for the Pittsburgh Sleep Quality Index in Older Adults

University of California, Cousins Center for Psychoneuroimmunology, Los Angeles, CA 90095-7076, USA.
Sleep (Impact Factor: 4.59). 02/2006; 29(1):112-6.
Source: PubMed


The Pittsburgh Sleep Quality Index (PSQI) is widely used to assess subjective sleep disturbances in psychiatric, medical, and healthy adult and older adult populations. Yet, validation of the PSQI single-factor scoring has not been carried out.
The PSQI was administered as a self-report questionnaire. Using a cross-validation approach, scores from the PSQI were analyzed with exploratory and confirmatory factor analyses.
San Diego, Denver, and Los Angeles community-based clinics.
Community-dwelling depressed and nondepressed adults older that 60 years of age (N = 417)
Results yielded a 3-factor scoring model that obtained a measure of perfect fit and was significantly better fitted than either the original single-factor model or a 2-factor model. Components of the 3 factors were characterized by the descriptors sleep efficiency, perceived sleep quality, and daily disturbances.
These findings validate the factor structure of the PSQI and demonstrate that a 3-factor score should be used to assess disturbances in three separate factors of subjective sleep reports.

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Available from: Michael R Irwin, Mar 16, 2014
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    • "Four CFA models were specified for Time 1 and Time 2 data: the original one-factor model [5], a two-factor model [12], a three-factor model [6], and a revised one-factor model. "
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    ABSTRACT: Objective The Pittsburgh Sleep Quality Index (PSQI) is used extensively to assess subjective sleep disturbance in cancer populations. Although previous studies on the PSQI suggested a better fit for a two- or three-factor model than the original one-factor model, none accounted for the indicator-specific effect between sleep duration and habitual sleep efficiency. This study evaluated the PSQI’s dimensionality and its convergent validity with cancer-related psychopathological states in female breast cancer patients. Methods The PSQI was administered to 197 women with breast cancer. Confirmatory factor analysis examined the relative fit of one-, two-, three-, and revised one-factor models. The PSQI’s convergent validity was evaluated via bivariate correlations between the PSQI factor scores and measures of anxiety, depression, fatigue, pain, and quality of life. Results Confirmatory factor analyses showed an adequate fit for the revised one-factor model with the PSQI global score as the overall index of sleep disturbance. Although the revised one- and two-factor solutions showed statistically equivalent model fits, the one-factor model was selected due to utility reasons. The severity of sleep dysfunction that the PSQI global score represented was positively correlated with anxiety, depression, fatigue, pain, and reduced quality of life. Conclusion The results support the PSQI’s original unidimensional structure, demonstrating that the PSQI global score is a valid and parsimonious measure for assessing and screening sleep dysfunction in cancer patients.
    Sleep Medicine 05/2014; 15(5). DOI:10.1016/j.sleep.2013.10.019 · 3.15 Impact Factor
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    • "A three-factor model of the PSQI was also found to have a better fit in a sample of renal transplant recipients [9] as well as in a sample of chronic fatigue syndrome patients [10]. Cole et al. found that the PSQI factor structure has three separate factors, that is, dimensions of sleep efficiency, perceived sleep quality, and daily disturbances and these are reported as 3 separate scores [6]. "
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    ABSTRACT: This study assessed the dimensional structure of sleep quality with the Pittsburgh Sleep Quality Index (PSQI) and investigated its psychometric properties in cases with temporomandibular disorders (TMD). A convenience sample of 609 TMD cases (age: 37.1 + 13.1 yrs, 18-67 yrs, 85% female) of the multi-center Validation Project meeting Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and with sufficient PSQI data were included in this study. To investigate PSQI scores' dimensionality, exploratory factor analysis was used. Factors were identified using the Scree plot. To investigate internal consistency, Cronbach's alpha was calculated. Analyses were separately performed for TMD cases with (N = 496) and TMD cases without a pain-related diagnosis (N = 113). The mean PSQI score for all TMD cases was 7.1 + 4.0 units, range: 0-19. The exploratory factor analysis identified one factor for cases with at least one pain-related TMD diagnosis as well as one factor for cases with a pain-free TMD diagnosis that explained 41% of the variance in cases with pain-related TMD and 37% in cases with pain-free TMD. Internal consistency for PSQI scores was alpha of 0.75 in cases with pain-related TMD, alpha of 0.66 in cases with pain-free TMD and alpha = 0.75 for all TMD cases. Sleep quality in TMD patients is a unidimensional construct and can therefore be represented by one summary score; a finding that is in line with previous reports in TMD patients.
    Health and Quality of Life Outcomes 01/2014; 12(1):10. DOI:10.1186/1477-7525-12-10 · 2.12 Impact Factor
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    • "Therefore, the relation between sleep and depression may change further as people reach older age. An examination of the relation between age and PSQI factor scores (Cole et al., 2006), after controlling for gender, psychological factors, and risk of SDB, also revealed interesting findings. "
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    ABSTRACT: Controversy exists as to whether self-reported sleep quality declines with age, despite changes in sleep being accepted as part of normal aging. This study sought to investigate age-related differences in self-reported sleep quality, after controlling for conditions that are common with age, such as psychological symptoms and increased risk of sleep-disordered breathing (SDB). The Pittsburgh Sleep Quality Index (PSQI) was administered to a sample of 582 community adults (aged 18-89 years), and the association between age and 3 factors of the PSQI (sleep efficiency, perceived sleep quality, and daily disturbance), and global scores, was examined controlling for depression, anxiety, stress, gender, and SDB risk. Results indicate that (a) before controlling for covariates, there was no significant relation between age and all indexes of self-reported sleep quality, with the exception of sleep efficiency. However, once depression, gender, and SDB risk were controlled for, a significant, yet small, relation was revealed between older age and poorer global sleep quality; (b) there was no association between age and perceived sleep quality or daily disturbances before or after controlling for relevant covariates; and (c) depression, gender, and SDB risk were significant predictors of poorer sleep quality across the indexes but, in general, did not have a marked impact on the relation between age and sleep quality. In conclusion, results suggest that sleep problems are common across the lifespan, and that there were modest age-related differences in self-reported sleep quality, which were not due to depressed mood, gender, or risk of SDB.
    Behavioral Sleep Medicine 06/2013; 12(3). DOI:10.1080/15402002.2013.801343 · 2.34 Impact Factor
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