German version of the reduced Morningness–Eveningness Questionnaire (rMEQ)

Abstract

The Morningness–Eveningness Questionnaire (MEQ) is the most widely known questionnaire to assess circadian preference. In the present study, the reduced MEQ (rMEQ), a short five-item version of the MEQ, is adapted to German language. A total of 594 participants filled in the German rMEQ and the Composite Scale of Morningness to measure convergent validity. Mean rMEQ scores were 13.97 ± 3.44 and ranged from 5 to 24. Cronbach's α was 0.723 for the total sample and 0.722 in men and 0.701 in women. Cutoff scores showed 126 (21.2%) morning types, 385 (64.8%) neither types, and 83 (14.0%) morning types. A principal component analysis with varimax rotation revealed a single-factor solution. The correlation between the Composite Scale of Morningness and the rMEQ was 0.885. Based on the type classification, there was a good agreement (Cramer coefficient = 0.622). The data presented here show that the rMEQ is also a reliable tool in its German adaptation, but the cutoff scores should be refined and discussed in further work.