Exploratory factor analysis of the Modified Somatic Perception Questionnaire on a sample with insomnia symptoms

Area of Science:

• Psychometrics
• Sleep Medicine
• Mental Health Research

Background:

• The Modified Somatic Perception Questionnaire (MSPQ) is commonly used to assess somatic symptoms.
• Its underlying factor structure, particularly in populations with insomnia symptoms, requires further investigation.

Purpose of the Study:

• To investigate the factorial structure of the Modified Somatic Perception Questionnaire (MSPQ).
• To examine the MSPQ's psychometric properties in a general population sample experiencing insomnia symptoms.

Main Methods:

• A cross-sectional study utilized a randomly selected general population sample (N=3600).
• 251 respondents with insomnia symptoms completed the MSPQ, alongside measures of anxiety, depression, and sleep-related factors.
• Exploratory factor analysis and correlational analyses were employed to determine the MSPQ's structure.

Main Results:

• A two-factor solution emerged from the 13-item MSPQ, explaining 47.31% of the variance.
• Factor 1 (10 items) represented general somatic arousal (alpha = 0.83), and Factor 2 (3 items) assessed stomach symptoms and nausea (alpha = 0.78).
• Both factors demonstrated significant inter-correlations, associations with total MSPQ scores, discriminant validity with anxiety/depression, and predictive validity for sleep medication use and healthcare consumption.

Conclusions:

• Contrary to the assumption of a single factor, a two-factor structure appears to be a better fit for the MSPQ in individuals with insomnia symptoms.
• These findings highlight the need for further research to validate the factorial solution of the MSPQ in diverse populations.