[Development of a test for the objective classification of types of circadian phase]

The authors deal with the question of interindividual differences in the circadian periodicity of man and with the possibility of the classification of circadian phase types resulting from this (morning type, evening type, indifference type). For this purpose on 26 test persons on 3 consecutive days at 9 o'clock and at 17 o'clock, respectively, 11 different vegetatively influenced parameters were measured. The quotients from the averaged 9 o'clock and 17 o'clock-values (Q 9/17) formed the basis for the statistical evaluation (cluster analysis in combination with a discriminance analysis). The result of the discrimination was compared with a subjective subdivision of our test group, based on a questionnaire newly developed by the authors, and yielded a portion of error of 4%. Issuing from this, the authors demonstrate an objective investigation method which shall allow to classify any patients simply, quickly and with high reliability into morning, evening and indifference types, respectively.