Relationship between self-rating and polygraphic sleep parameters - analysis of compiled data from 12 young Japanese...

An examination of the relationship of the self-rating sleep score to polygraphic sleep parameters was conducted. The self-rating sleep questionnaire, OSA, includes five sleep quality factors: sleepiness (Fl), sleep maintenance without interruption (F2), worry about daily life or poor emotional condition (F3), integrated or perceived sleep feeling (F4) and sleep initiation or induction (F5). Polygraphic sleep parameters including each sleep stage in minutes were used. If intercorrelation coefficients exceeded 0.8, only one of the related parameters was selected for multivariate analysis. Twelve male students slept a total of 88 nights, among which the first night was not included, in an experimental room. When absolute values of Spearman's rank correlation coefficient of not less than 0.4 were tentatively selected, the following pairs were extracted: F2 score and S1 (-0.423) or S3+S4 (0.409), F5 score and sleep latency (-0.439). Deeper sleep was closely associated with sleep maintenance without interruption. Agreement between self-rating and a polygraphic sleep parameter was recognized between the F5 score and sleep latency. Each OSA factor score was predicted by other polygraphic sleep parameters using multiple regression analysis. MT significantly contributed to the Fl, F3 and F4 scores. The number of stage shifts per night significantly contributed to the Fl and F3 scores, and the number of sleep spindles significantly contributed to the F5 score. Though prediction of sleep quality by polygraphic sleep parameters is limited, the association between concrete subjective and objective sleep parameters was clarified as mentioned above, and their practical meaning was partially elucidated.