Showing papers by "Shosuke Suzuki published in 1997"
TL;DR: It is suggested that road traffic noise raises the sound level in bedrooms in such zones, and consequently the prevalence rate of insomnia among the residents, and that noise-induced insomnia is an important public health problem, at least in highly urbanized areas.
Abstract: In an effort to identify risk factors for insomnia and determine the contribution of nightime road traffic volume to insomnia in the general population, a questionnaire survey was carried out among 3,600 adult Japanese women living in eight urban residential areas. The crude prevalence rate of insomnia was 11.2%. Multivariate analysis revealed that aging, living with a child/children aged six or younger, undergoing medical treatment, experiencing major life events, having an irregular bedtime, having a sleep apnealike symptom, and living near a road with a heavy volume of traffic are risk factors for insomnia. Taking into account other risk factors, there was a level-response relationship between the nighttime traffic volume of main roads and the risk of insomnia in the subjects living in the zones 0-20 m from these roads. These results suggest that road traffic noise raises the sound level in bedrooms in such zones, and consequently the prevalence rate of insomnia among the residents, and that noise-induced insomnia is an important public health problem, at least in highly urbanized areas. To confirm this, a further study on noise exposure is needed.
83 citations
TL;DR: The authors speculate that the decrease in the shallow stage as noisy nights were repeated reflects habituation of night sleep to repeated passing truck noise, whose interval, duration and nature was constant.
10 citations
TL;DR: In this paper, 3600 adult Japanese women living in urban residential areas were surveyed to determine the contribution of night-time road traffic noise to insomnia in the general population, and the risk for insomnia in zones 0-20 m from the main roads increased linearly with the nighttime traffic volume.
7 citations
TL;DR: In this paper, 12 subjects were exposed to the noise of passing trucks at peak levels of 45, 50, 55 and 60 dB(A) for 15 min intervals throughout the night each for seven to 12 nights.
5 citations
TL;DR: Increases in the percentages of difficulty in inducting and maintaining sleep, early morning awakening and worry about poor sleep quality in the subjects in their sixties, and sleep dissatisfaction of those in their thirties were recognized.
Abstract: The prevalence rate of insomnia among 424 married women and its associated factors were surveyed Insomnia is defined as having one of the following symptoms one or more times per week: difficulty inducing sleep (Fl), difficulty maintaining sleep (F2), early morning awakening (F3), light sleep (F4), or worry about poor sleep quality (F5) Poor sleep as a whole in the past one month (F6) was also inquired about Percentages of Fl, F2, F3 and F5 among the subjects in their sixties were 213%, 133%, 67% and 107%, respectively, relatively higher than those of subjects in their thirties or forties There was a significant difference in the percentage of F6 among four age categories (p < 005), and the percentage of F6 was highest (233%) in those in their thirties Depressive state correlated with six insomnia items, Fl to F6 (rs=-0195, -0161, -0117,-0221, -0176, 0284, respectively) Perceived health status correlated with Fl (-0237), F4 (-0213), F5 (-0259), and F6 (0373) Present medical condition correlated with Fl (-0195), F3 (-0146), and F5 (-0220) The prevalence rates of insomnia for subjects in their thirties, forties, fifties and sixties were 167%, 177%, 257%, and 240%, respectively Increases in the percentages of difficulty in inducting and maintaining sleep, early morning awakening and worry about poor sleep quality in the subjects in their sixties, and sleep dissatisfaction of those in their thirties were recognized
5 citations
TL;DR: Though prediction of sleep quality by polygraphic sleep parameters is limited, the association between concrete subjective and objective sleep parameters was clarified, and their practical meaning was partially elucidated.
Abstract: 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.
4 citations
TL;DR: The authors attempted to ascertain the working conditions of physicians employed in large hospitals in Gunma Prefecture, Japan, and found that they cannot take enough holidays and have little time to study or to refresh the knowledge essential to their professional lives.
Abstract: The government of Japan is now implementing a policy aimed at reducing the occupational working hours, for all types of labor in Japan, to 40 hrs/week and 1, 800 hrs/year. The implementation of this policy began in 1988 and is scheduled to be completed in 1997. In fact, average working hours have decreased, reaching 1, 904hrs/year in 1995, a level comparable to those of the USA and the United Kingdom. Physicians have, however, been dealt with differently from other hospital workers. Even physicians employed in large hospitals seem to work harder for a longer time than ever. The authors attempted to ascertain the working conditions of physicians employed in large hospitals in Gunma Prefecture, Japan. Twenty-four male physicians in their 30s of age, working in national university hospitals and relatively large private and public hospitals, were randomly selected from the membership list of the alumni association of a national medical school in the same prefecture. A questionnaire was prepared to include the following items: working hours, number of holidays, annual income, actual time budget on seven successive days. The questionnaire was distributed by an interviewer after obtaining each subject's consent to participate in the survey. After a week or more the interviewer retrieved the filled-in forms. Intotal, 19 physicians responded. Average working hours for 11 university hospital physicians (UP) and 8 other hospital physicians (HP) were 2, 781 and 2, 346 hrs/year, or 66.3 and 57.7 hrs/week, respectively. Average weekly working hours of approximately 5, 000 general and non-general physicians sampled in the USA were 51 hrs in 1980, based on a periodic survey conducted by the American Medical Association.Numbers of holidays per year for UP and HP were 57.8 and 69.6 days, respectively, though the number for workers employed in Gunma Prefecture was 107.5 days. Incomes per year for UP were 3.79 million yen from the university hospital and 4.86 from hospitals employed as part timers, a total of 8.65 million yen, while that of HP was 12.56 million yen. The UP time budgets for primary (sleep, etc.), secondary (work, etc .) and tertiary (learning, etc.) activities were 70.4, 71.2 and 24.4 hrs/week, respectively; these figures were almost the same as those of HP. The longer the secondary activity time the shorter the primary and tertiary activity times. The shift system and the team approach for physicians employed in hospitals are so inadequate that they cannot take enough holidays and have little time to study or to refresh the knowledge essential to their professional lives.
4 citations