Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2012 Feb;13(2):207-10.
doi: 10.1016/j.sleep.2011.06.019. Epub 2011 Dec 14.

The Spanish version of the Insomnia Severity Index: a confirmatory factor analysis

Julio Fernandez-Mendoza  1 , Alfredo Rodriguez-Muñoz, Antonio Vela-Bueno, Sara Olavarrieta-Bernardino, Susan L Calhoun, Edward O Bixler, Alexandros N Vgontzas
Affiliations

The Spanish version of the Insomnia Severity Index: a confirmatory factor analysis

Julio Fernandez-Mendoza et al. Sleep Med. 2012 Feb.

Abstract

Objective: To examine the psychometric properties of the Spanish version of the Insomnia Severity Index (ISI) and to determine its factor structure with confirmatory factor analysis (CFA).

Methods: Self-reported information was collected from a sample of 500 adults (mean age 39.13 [standard deviation 15.85]years) drawn from a population of medical students and their social networks. Together with the ISI, a measure of the subjective severity of insomnia, subjects completed the Pittsburg Sleep Quality Index, the Epworth Sleepiness Scale, and the Profile of Mood States to study concurrent validity of the ISI. CFA was used to test alternative models to ascertain the factorial structure of the ISI.

Results: The Spanish version of the ISI showed adequate indices of internal consistency (Cronbach's α=0.82). CFA showed that a three-factor structure provided a better fit to the data than one-factor and two-factor structures. The ISI was significantly correlated with poor sleep quality, fatigue, anxiety, and depression, and discriminated between good and poor sleepers.

Conclusions: The ISI is a reliable and valid instrument to assess the subjective severity of insomnia in Spanish-speaking populations. Its three-factor structure (i.e., night-time sleep difficulties, sleep dissatisfaction and daytime impact of insomnia) makes it a psychometrically robust and clinically useful measure.

PubMed Disclaimer

Publication types