Modified Munich chronotype questionnaire for application to short-interval split sleep of non-shift workers

Area of Science:

• Chronobiology
• Sleep Science
• Psychometrics

Background:

• The Munich Chronotype Questionnaire (MCTQ) is a validated tool for chronotype assessment.
• Chronotype determination in individuals with split sleep patterns, especially on free days, remains underexplored.
• Split sleep involves short intervals between sleep bouts, posing challenges for traditional chronotype assessment.

Purpose of the Study:

• To validate a modified version of the Munich Chronotype Questionnaire (MCTQ) for individuals with split sleep patterns.
• To assess the accuracy of the modified MCTQ by comparing its sleep-wake timing measures against the Morningness-Eveningness Questionnaire (MEQ).
• To adapt the calculation of midpoint of sleep on free days (MSF) for split sleep patterns.

Main Methods:

• Recruited 161 participants (38.7 ± 7.8 years; 73% female), including 29% with split sleep patterns.
• Administered the modified MCTQ and the Morningness-Eveningness Questionnaire (MEQ).
• Modified the MSF calculation to consider the second sleep bout as total sleep duration for split sleepers.

Main Results:

• Original MCTQ parameters (MSW, MSF, MSF_sc) showed significant correlations with MEQ scores (r ≈ -0.57).
• The modified MSF for split sleep, calculated within 60 minutes after the first awakening, exhibited the highest correlation with MEQ (r = -0.576).
• All tested MCTQ parameters demonstrated significant correlations with MEQ, indicating validity.

Conclusions:

• The modified MCTQ is a valid instrument for determining chronotype in individuals with both consolidated and split sleep patterns.
• This adapted questionnaire addresses the limitations of traditional chronotype assessment in populations with fragmented sleep.
• The findings support the use of the modified MCTQ for accurate chronotype assessment across diverse sleep schedules.