Related Experiment Video
Updated: Jan 23, 2026

Author Spotlight: Unveiling the Connection Between Sleep Disorders and Cognitive Symptoms in Depression
Published on: April 26, 2024
Psychometric evaluation of the Freedman questionnaire to assess sleep in critical patients
M D Bernat Adell1, E Bisbal Andrés2, L Galarza Barrachina2
1Unidad Predepartamental de Enfermería, Universitat Jaume I, Castellón, España.
Aim:
A study was made of the psychometric characteristics of the modified Freedman questionnaire to assess sleep in critical patients.
Design:
A psychometric study was carried out, with content validity being explored by a group of experts, and internal consistency based on Cronbach's alpha coefficient. Factor analysis was performed to explore construct validity, and stability was assessed by test-retest analysis.
Setting:
The Department of Intensive Care Medicine of a reference hospital.
Participants:
Patients admitted between 23 February 2016 and 20 December 2017.
Interventions:
Questionnaire administration.
Variables:
Items of the modified Freedman questionnaire.
Results:
Item relevance and definition yielded scores >3 (Likert scale maximum=4). Cronbach's alpha showed a global value of 0.933. The intraclass correlation index was >0.75 for most of the items of the questionnaire. Factor analysis allowed the detection of specific associations between the studied variables and the four factors.
Conclusions:
The modified Freedman questionnaire showed good psychometric characteristics. It may be a reliable instrument for assessing the quality of sleep in critically ill patients, as well as the environmental factors.
Related Concept Videos
Insufficient Sleep and Sleep Deprivation
Sleep deprivation is a more severe form of sleep loss...
Critical Region, Critical Values and Significance Level
In hypothesis testing, a sample statistic is converted to a test statistic using z, t, or chi-square distribution. A critical region is an area under the curve in probability distributions demarcated by the critical value. When the test statistic falls in this region, it suggests that the null hypothesis must be rejected. As this region contains all those values of the...
Critical Values
Stages of Sleep
Before sleep begins, in wakefulness, the brain exhibits primarily beta waves, which are high in frequency and low in amplitude, indicating alertness...
Critical Thinking
Colleges and universities are...
Critical Thinking I

