Validation of the three-factor model of the PSQI in a large sample of chronic fatigue syndrome (CFS) patients

Department of General Internal Medicine, Infectious Diseases and Psychosomatic Medicine, University Hospital Ghent, Belgium.
Journal of psychosomatic research (Impact Factor: 2.84). 02/2012; 72(2):111-3. DOI: 10.1016/j.jpsychores.2011.11.004
Source: PubMed

ABSTRACT To evaluate whether a 3-factor model of the Pittsburgh Sleep Quality Index (PSQI) scale would fit the constellation of sleep disturbances in patients with a diagnosis of chronic fatigue syndrome (CFS).
Consecutive CFS patients filled out the PSQI. Scores from this self-report questionnaire were examined with exploratory and confirmatory factor analysis (CFA).
413 CFS patients were included for analysis in this study. CFA showed that the 7 PSQI component scores clustered into the 3 factors reported by Cole et al. (2006), i.e. Sleep Efficiency, Perceived Sleep Quality and Daily Disturbances. In contrast with the single-factor and all 2-factor models, all factor loadings were significant, and all goodness-of-fit values were acceptable.
In CFS, the PSQI operates as a 3-factor scoring model as initially seen in healthy and depressed older adults. The separation into 3 discrete factors suggests the limited usefulness of the global PSQI as a single factor for the assessment of subjective sleep quality, as also evidenced by a low Cronbach's alpha (0.64) in this patient sample.

  • [Show abstract] [Hide abstract]
    ABSTRACT: The Pittsburgh Sleep Quality Index (PSQI) is a widely used measure for assessing sleep impairment. Although it was developed as a unidimensional instrument, there is much debate that it contains multidimensional latent constructs. We examined the dimensionality of the underlying factor structure of PSQI in Singapore, a rapidly industrialising Asian country with multi-ethnicities representing the Chinese, Malays and Indians. The PSQI was administered through an interviewer-based questionnaire in two separate population-based cross-sectional surveys. An explanatory factor analysis (EFA) was first used to explore the underlying construct of the PSQI in both studies. Then, a confirmatory factor analysis (CFA) was conducted to evaluate an optimal factor model by comparing against other possible models identified in EFA. There are three correlated yet distinguishable factors that account for an individual's sleep experience from the same best-fit model obtained in both studies: perceived sleep quality, daily disturbances and sleep efficiency. Our three-factor structure of PSQI is superior to the originally intended unidimensional model. Our model also shows the best-fit indices when compared to the previously reported single-factor, two-factor and three-factor (by Cole et al.) models in a multi-ethnic Asian population. There is strong evidence that the PSQI contains a three-factor rather than a unidimensional structure in a multi-ethnic Asian population. Scoring the PSQI along their multidimensional perspectives may provide a more accurate understanding of the relationship between sleep impairment and health conditions rather than using a single global score.
    Sleep And Breathing 02/2015; DOI:10.1007/s11325-015-1130-1
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Introduction. Mild traumatic brain injury (mTBI) has been widely studied and the effects of injury can be long term or even lifelong. This research aims to characterize the sleep problems of patients following acute mTBI. Methods. A total of 171 patients with mTBI within one month and 145 non-mTBI controls were recruited in this study. The questionnaire, Pittsburgh Sleep Quality Index (PSQI), was used to evaluate seven aspects of sleep problems. A propensity score method was used to generate a quasirandomized design to account for the background information, including gender, age, Beck's Anxiety Index, Beck's Depression Index, and Epworth Sleepiness Scale. The effect was evaluated via cumulative logit regression including propensity scores as a covariate. Results. Before adjustment, about 60% mTBI patients and over three quarters of control subjects had mild sleep disturbance while one third mTBI patients had moderate sleep disturbance. After adjusting by the propensity scores, the scores of sleep quality and duration were significant between mTBI and control groups. Conclusion. Our study supports that sleep problem is common in mTBI group. After adjusting the confounders by propensity score, sleep duration and subjective sleep quality are the most frequently reported problems in mTBI patients within one month after the injury.
    Behavioural neurology 01/2015; 2015:378726. DOI:10.1155/2015/378726
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Although ample research has shown the satisfaction of the basic psychological needs for autonomy, competence, and relatedness, as defined within Self-Determination Theory, to be related to well-being, the relation with sleep-related functioning has not yet been examined. Hence, the present study explored the association between basic psychological need satisfaction and subjective measures of sleep and daytime dysfunction, as well as the explanatory role of need satisfaction in the relation between mindfulness and financial strain and these outcomes, in an adult sample (N = 215, 61% female; Mean age = 31). The results indicated that low psychological need satisfaction related to poor sleep quality, lower sleep quantity, and more daytime dysfunction. Finally, mindfulness and financial strain related, respectively, negatively and positively to poor sleep quality and daytime dysfunction through need satisfaction, suggesting that need satisfaction represents a critical explanatory mechanism. The role of psychological need satisfaction in the adequate regulation and satisfaction of the physiological need for sleep is discussed.
    Personality and Individual Differences 04/2015; 77. DOI:10.1016/j.paid.2015.01.003


Available from
Jun 5, 2014