The relationship of sleep complaints risk factors with sleep phase, quality, and quantity in Japanese workers.

Numerous studies have determined that lifestyle factors (smoking, drinking, snacking, etc.) and the bedroom environment can influence sleep. We developed a new sleep scale-the 3-Dimensional Sleep Scale (3DSS)-which measures three elements of sleep: phase, quality, and quantity. The purpose of this study is to determine which risk factors of sleep complaints are associated with these sleep elements. Data were obtained from 366 Japanese day workers (302 men and 64 women). Sleep condition was assessed with the 3DSS, and we also assessed various habits within 2 h of going to bed, including smoking, drinking, snacking, caffeine intake, mobile phone use, and working. We also asked about bedroom environmental conditions (noise, lighting, and temperature and humidity). Multivariate logistic regression analysis using the backward selection method (likelihood ratio) was used, with 3DSS scores as the outcome (i.e., over or under the cutoff). The results showed that smoking was associated with significantly greater odds ratio [2.71 (1.65-4.44)] of disordered sleep phase, while lighting as well as temperature and humidity led to greater odds [3.67 (1.55-8.68), 1.93 (1.20-3.11)] of poor sleep quality. Finally, only noise was significantly related to greater odds [1.98 (1.13-3.46)] of low sleep quantity. These findings indicated the various risk factors of sleep complaints could be associated with different sleep elements. This might help in the effective treatment of sleep complaints.

Day workers suffering from a wider range of sleep problems are more likely to experience suicidality.

Both a higher suicide rate and widespread sleep problems are serious health concerns in Japan when compared with those of other countries. We investigated the relationship between suicidal ideation and sleep problems in Japanese day workers using the 3-dimensional sleep scale (3DSS), which measures three sleep elements (phase, quality, and quantity). Data from 635 Japanese day workers (461 mens and 174 womens) were included. The 3DSS was used to assess participants' sleep condition. Participants were classified into eight sleep types based on scores of phase, quality, and quantity: All Good Sleep, Owl (poor phase), Inefficient (poor quality), Short (poor quantity), Owl + Inefficient (poor phase and quality), Owl + Short (poor phase and quantity), Inefficient + Short (poor quality and quantity), and All Poor Sleep. We assessed participants' suicidal ideation using question 19 of the self-rating depression scale (SDS); 119 cases (18.7 %) had ratings of 2-4 for this question and were considered to have suicidal ideation. The higher the number of sleep problems, the higher the risk of suicidal ideation compared to sleep types not indicative of problems. All Poor Sleep had the highest risk of the eight sleep types. Individuals with Owl + Short, Inefficient + Short, or All Poor Sleep had a significant risk of suicidal ideation even after adjusting for hopelessness and nightmares. Our findings suggested that sleep problems assessed by the 3DSS were related to suicidal ideation. Analysis of various aspects of sleep could be helpful for suicide prevention.

Comparison of subjective symptoms associated with exposure to low levels of formaldehyde between students enrolled and not enrolled in a gross anatomy course.

OBJECTIVES: This study aimed to evaluate students' subjective symptoms associated with exposure to low levels of formaldehyde (FA) during a gross anatomy course and to survey how the risk of subjective symptoms was affected by exposure to FA. METHODS: We conducted three questionnaire surveys of 125 students enrolled in an anatomy course (FA exposure group) and 124 students not enrolled in the course (FA nonexposure group) before, during, and 6 months after the course. The questionnaire included questions inquiring about subjective symptoms, sex, age, and allergies. We analyzed differences in the prevalence of subjective symptoms in distinct survey periods. Furthermore, we analyzed the relationship between the subjective symptoms and exposure to FA after adjusting for allergy, sex, and age using multiple logistic regression analysis. RESULTS: The prevalence of some of the ocular, nasal, and nonspecific symptoms in the FA exposure group was low before the course, increased during the course and decreased 6 months after the course. A significant positive relationship was observed between exposure to FA and some symptoms after adjusting for allergy, sex, and age. CONCLUSIONS: We identified some concrete symptoms associated with exposure to FA. We suggest that the exposure to low levels of FA influences students' subjective symptoms.

Investigation of the relationship between convenient visits and doctors' fatigue using burnout and work engagement scales.

OBJECTIVES: Fatigue caused by high workload is often responsible for the high attrition among doctors, and has contributed to a disruption in community medicine. In order to address this problem, institutional mechanisms at the hospital level are required. Previous studies have shown that systemic measures at the hospital level and a change in the mindset of patients can help manage the problem. "Convenient visits" refer to emergency visits for non-emergency problems. It is an avoidable cause of high workload on doctors. Convenient visits also refer to emergency consultation for non-emergency symptoms. As this is a new phenomenon, its relationship with doctors' fatigue needs further research. We investigated the relationship between convenient visits and doctors' fatigue using burnout and work engagement scales. METHODS: We selected 44 hospitals, with >200 beds each, in provincial cities of prefectures with a doctor-population ratio lower than the national average. These cities were considered likely to manifest the phenomenon of 24-hour society and include overworked doctors. Ordinance-designated cities were excluded from this study owing to wide population variability. Three doctors from each hospital were randomly selected from among physicians, surgeons, and pediatricians. We distributed questionnaires (a questionnaire concerning convenient visits, Maslach Burnout Inventory-Human Services Survey, and Utrecht Work Engagement Scale) to 132 doctors. RESULTS: Forty-two doctors responded to the survey. The median proportion of convenient visits among emergency visits was 50%. Sixty percent of the doctors surveyed were annoyed by convenient visits. Other doctors indicated good collaboration between the hospitals and communities or that they were not currently annoyed by convenient visits, although they had been annoyed previously. The emotional exhaustion in doctors, who worked in hospitals that did not restrict convenient visits, was significantly higher than in those who worked in hospitals that restricted these visits. A significant risk of serious burnout was found via crude and multiple logistic regression analysis (adjusted for age and gender, or adjusted for age, gender, clinical department, frequency of work shifts, and sleep duration during work shifts). CONCLUSION: Doctors working in hospitals that do not protect them against convenient visits are more prone to burnout. Although the number of convenient visitors is increasing, many hospitals lack systemic measures to manage them. This contributes to doctors' burnout. We suggest that hospitals control convenient visits for preventing doctors' burnout. Collaboration between hospitals and communities is required to help alleviate this problem.

[Reliability and validity of the 3 Dimensional Sleep Scale (3DSS)--day workers version--in assessing sleep phase, quality, and quantity].

OBJECTIVES: Most sleep scales assess sleep quantity (e.g., sleep duration and daytime sleepiness) or sleep quality (e.g., sleep latency and maintenance); the Pittsburgh Sleep Quality Index (PSQI) is an exceptional example. However, the prevalence of 24-hour operations presents the need for a scale that can also measure sleep phase (e.g., sleep onset and offset). Furthermore, we have to assess the phase, quality and quantity respectively to understand which of them has a problem. Thus, the 3 Dimensional Sleep Scale (3DSS) - day workers version - was developed to assess each of them related to sleep, and this study attempted to verify its reliability and validity. METHODS: Subjects were 635 day workers (461 men, 174 women; average age = 40.5 years) from the manufacturing and service industries. A scale was created based on a pre-study and discussions with specialists. The scale consisted of 17 sleep-related items. The skew of the data was assessed, and the construct validity and reliability were verified using exploratory and confirmatory factor analysis and Cronbach's alpha, respectively. The scale was scored and G-P analysis was performed. The items measuring phase, quality, and quantity of sleep were selected from the PSQI and SDS, and their correlation with the three scales of 3DSS were measured to verify the convergent and discriminant validity. In addition, the total scores obtained on the PSQI were compared with each scale of the 3DSS. RESULTS: No skew was found in the data. Exploratory factor analysis revealed a three-factor structure--quality, quantity, and phase. Each factor consisted of five items, therefore two items were excluded. The fitness of the 15-item model was better than that of the 17-item model according to confirmatory factor analysis. Cronbach's alpha for phase, quality and quantity score were 0.685, 0.768 and 0.716, respectively. The hypothesis tests were almost accepted, therefore convergent and discriminant validity were sufficiently established. CONCLUSIONS: The present study established the reliability and validity of the 3DSS; however, further studies using larger samples are needed to standardize the test and to establish a cut-off value.

Doppler detection in Ama divers of Japan.

OBJECTIVE: Symptoms consistent with neurological decompression sickness (DCS) in commercial breath-hold (Ama) divers has been reported from a few districts of Japan. The aim of this study was to detect circulating intravascular bubbles after repetitive breath-hold diving in a local area where DCS has been reported in Ama divers. METHODS: The participants were 12 partially assisted (descent using weights) male Ama divers. The equipment (AQUALAB system) consisted of continuous-wave Doppler with a 5-MHz frequency, and the Doppler probe was placed in the precordial site with the ultrasonic wave directed into the pulmonary infundibulum. We carried out continuous monitoring for 10 minutes at the end of the series of repetitive dives, and the recordings were made on numerical tracks and graded in a blind manner by 2 experienced investigators, according to the Spencer Doppler code. RESULTS: Depths and number of dives were 8 to 20 m and 75 to 131 times. Mean diving duration and surface interval were 64 ± 12 seconds and 48 ± 8 seconds, respectively (mean ± SD). We detected the lowest grade of intravascular bubbles (Spencer's grade I) in an Ama diver whose mean surface interval was only 35.2 ± 6.2 seconds. His mean descending, bottom, and ascending times were 10.4 ± 1.6 seconds, 39.2 ± 8 seconds, and 18.2 ± 3.0 seconds, respectively, over the course of 99 dives. CONCLUSIONS: Intravascular bubbles may be formed after repetitive breath-hold dives with short surface intervals or after a long breath-holding session in Ama divers. Symptoms consistent with neurological accidents in repetitive breath-hold diving may be caused in part by the intravascular presence of bubbles, indicating the need for safety procedures.

Development of a Scale for Assessing Three Aspects of Sleep: Regularity, Quality, and Quantity.

Objectives: It is difficult to assess sleep habits using one factor (i.e., sleep duration) alone. Regularity and quality of sleep have to be considered to assess sleep accurately. However, to our knowledge there is no scale which scores the three factors simultaneously. The purpose of this study was to inspect the reliability and validity (content, construct, and discriminant validity) of a scale we developed to screen for poor sleep habits. This scale was constructed to assess three aspects of sleep: regularity, quality, and quantity. Methods: Subjects were 563 day workers (370 men and 193 women; average age = 40.4 yr) from the manufacturing and service industries. We created a 21-item questionnaire (7 items for each of 3 factors) based on earlier studies and discussions with specialists. Reliability and construct validity of the questionnaire were assessed through item and factor analyses and Cronbach's alpha. In addition, subjects' scores were using principal component analysis, and subjects were classified according to their scores through a cluster analysis. We compared lifestyles, daytime sleepiness, stress, and chronic disease among the subjects to examine the instrument's discriminant validity. Results: Although our analysis revealed 6 items were invalid, the questionnaire assessed the three factors (regularity, quality and quantity) as expected: Cronbach's alpha was 0.744, 0.757, and 0.548, respectively. Two of the 7 quantity items were identified as assessing regularity instead, but all other items performed as expected. Four items measuring insomnia (disturbance of sleep induction, disturbance of sound sleep, nocturnal awakening, and early morning awakening) included constant burden as a quality factor. Chi-squared tests showed that the ratio of participants who took good care of their health and had less stress and daytime sleepiness was significantly high in the highest-scoring group, while the ratio of people reporting stress and chronic disease was significantly high in the lowest-scoring group. Conclusions: The questionnaire we developed for assessing three factors of sleep (regularity, quality and quantity) was determined to have construct validity. However, since some items were excluded and some assessed into another factor, sufficient reliability and content validity were not found. Revision is needed to improve the scale's accuracy, and we also have to examine detailed discriminant validity controlling for factors such as age and sex.

Changes in subjective symptoms and allergy state among medical students exposed to low-level formaldehyde 6 months after completion of a gross anatomy dissection course.

OBJECTIVES: Our purpose was to clarify whether subjective symptoms of low-level formaldehyde (FA) exposure in medical students were transient or persistent and to investigate whether the allergy state changed as a result of exposure. METHODS: We surveyed the prevalence of medical students' subjective symptoms and their allergy state before, during, and 6 months after completion of a gross anatomy dissection course by using two self-administrative questionnaires. Students completed the first survey at the end of the anatomy course to assess symptoms before and during the course. The second survey was completed 6 months after course completion. RESULTS: The prevalence of most subjective symptoms was lower 6 months after the course than during the course. The major symptoms experienced during the course were eye fatigue, runny nose, and dry eyes. The most common symptom 6 months after the course was eye fatigue. Four students continued to experience symptoms even after course completion. Three students developed symptoms only after course completion. Forty-eight students had allergies before the course began and the severity of the allergies did not change after the course. Additionally, the prevalence of most subjective symptoms 6 months after the course was lower than before the course. The patterns of subjective symptoms in the three periods differed between male and female students; the prevalence of most subjective symptoms tended to be higher in females. CONCLUSIONS: Subjective symptoms resulting from FA exposure during a gross anatomy course were transient and did not affect students' allergy states.

[Effect of large-scale repair work on indoor formaldehyde levels upon and subjective symptoms in, medical students during gross anatomy dissection course].

OBJECTIVES: To examine the effect of large-scale repair work on indoor formaldehyde (FA) levels and subjective symptoms in medical students during a gross anatomy dissection course. METHODS: We measured the indoor FA levels, room air temperature, and room humidity during a gross anatomy dissection course. In addition, the prevalence of subjective symptoms, keeping allergy state, and wearing personal protective equipment were surveyed in two groups of students using a self-administered questionnaire. RESULTS: The mean indoor FA levels before and after repair work were 1.22 ppm and 0.14 ppm, respectively. The mean indoor FA level significantly decreased after repair work. The prevalences of most subjective symptoms before the anatomy practice were similar before and after the repair work. However, the prevalences of most subjective symptoms during the anatomy practice were lower after the repair work. CONCLUSIONS: The mean indoor FA levels and prevalences of subjective symptoms decreased after the repair work. We have to continuously monitor indoor FA levels, carry out private countermeasures to minimize exposure to FA, and maintain equipment for ventilation to be able to conduct practice in a comfortable environment.

Association between the transition from unemployment to re-employment after abrupt bankruptcy and the depressive symptoms.

The study aimed to examine the effects of long-term unemployment and the transition from unemployment to re-employment after abrupt bankruptcy on the mental health of unemployed Japanese. The cases of 96 men and 54 women who were laid off by a large shoemaking company because of sudden bankruptcy in 1998, were examined for one year. The mental health of these individuals was evaluated using a 'self-rating questionnaire for depression (SRQ-D)'. The respondents were categorized by employment transition status into four groups: (1) still employed full-time, (2) unemployment to full-time employment, (3) unemployment to part-time employment, and (4) still unemployed. The prevalence rate of depressive symptoms in the 'still unemployed' group was significantly higher (adjusted odds ratio (OR) = 4.33) than in the still employed group. Moreover, high levels of depressive symptoms were observed in the individuals in the 'unemployment to part-time employment' group (adjusted OR = 4.93). There was no significant risk of depressive tendency among individuals in the 'unemployment to full-time employment' group. The results suggest that the negative effect of re-employment to part-time employment on depressive symptoms is similar to that in long-term unemployment.

[Modifications in health and welfare jobs transferred to thirty-five participating "core cities"].

PURPOSE: The aim of this study was to determine modifications in health and welfare jobs transferred to thirty-five participating "core cities. METHODS: We focused on health and welfare jobs in the following sectors: (1) local welfare; (2) health care; (3) city planning; (4) environmental protection; (5) education; and (6) urban revitalization. We developed a self-report questionnaire regarding implementation of administrative jobs transferred from prefectures to the core cities with attention to affects of changes in the jobs on the city administrative efficiency and the health of both the citizens and the city officials. The questionnaire, consisting of 27 multiple-choice and 12 open-ended questions, was forwarded via e-mail to lead city officials of the thirty-five core cities in mid-February 2008. RESULTS: Twenty-seven cities responded to the questionnaire in mid-March 2008 (collection rate: 77%). The core cities incorporated almost all the jobs transferred from the prefectures, in spite of some limitations regarding time taken for delivering assistive equipment to disabled children, implementing wider administrative plans and establishing educational centers. Almost all core cities answered that they implemented their jobs independently, autonomously and systematically. Seventeen out of 27 core cities established new health care centers during the transition period and increased their number of staff. The majority of these 17 answered that establishment of organizations directly providing services to citizens contributed to improvement in the efficiency of the administrative jobs. CONCLUSIONS: The core cities incorporated almost all the jobs transferred from the prefectures in spite of some limitations. The core cities which established their new health care centers during this transition period increased their number of staff to address modifications to the work load.

[Change of citizen's expectations for health activity in transition to a "Core City": focus on newly established public health centers].

PURPOSE: This article aims to predict the future course of city administration and public health centers through clarifying the actual state and local residents' expectations of new public health centers on becoming a "Core City". METHOD: Online questionnaire surveys targeting Kurume City residents were conducted in March 2008 (before becoming a Core City) and in October 2008, six months after becoming a Core City. Questions involved awareness of the Core City concept and the expectations for administration of the Core City and its new public health centers. RESULT: The recognition rate for the Core City concept was 62.6% in the first questionnaire survey and 78.9% in the second survey, demonstrating a significant increase (P < 0.001). The expectations for the Core City centered on "Vitalization of the city" in both surveys. However, in the second survey results, "Nothing in particular" accounted for 81.2% of the responses for what the residents felt as a change after becoming a Core City. On the other hand, "Vitalization of the city" recorded 5.5% for the same question, showing a low rate. "Health promotion, Cancer check-ups, and Vaccination" were the most commonly chosen responses regarding expectations of the new public health centers in both surveys, accounting for approximately 30%. Nonetheless, the response to a question asking about actual utilization of the public health centers revealed a high rate of 83.4% for "Nothing in particular" in the second survey result. The recognition rate for the "Health Promotional Members" system implemented by the Kurume City public health centers from 2007 was a low 6.5%. Furthermore, the responses to the "District-Assigned Public Health Service" system to be introduced from 2009 were: In favor 52.6%, Opposed 3.0%, and Neither 44.3%. CONCLUSION: Although residents' expectations of public health centers are high, the surveys revealed that the health promotional activities provided by the public health centers were not fully utilized. In the future, the recognition rate of the "District-Assigned Public Health Service" starting in 2009 should be improved as quickly as possible to enhance the support system to accommodate individual health needs.

Predictive factors of psychological disorder development during recovery following SARS outbreak.

OBJECTIVE: To investigate strategies for broad mass isolation during outbreaks of infectious diseases. DESIGN: A survey using a self-administered questionnaire was conducted on 300 printing company workers in Beijing, China, which was under mass isolation following the 2003 SARS outbreak, in the 7-8 months after the isolation was lifted. MAIN OUTCOME MEASURES: Individuals with psychological disorders were classified on the basis of scores on the 30-item General Health Questionnaire during the recovery period. Psychological disorders were observed in 49 of 187 respondents (26.2%; 95% CI = 20.2, 32.7). RESULTS: The predicting factor with the highest correlation was income reduction, with an odds ratio of 25.0. Other items obtained were gender, range of activities, eating restrictions, restrictions in going out, disinfection of clothing, and infection control, with odds ratios of 3.2, 5.5, 3.9, 3.2, 0.2, and 0.1, respectively, and the contribution ratio was 87.7%. CONCLUSION: Securing income is suggested to be important in future strategies.

Effect of short-term exposure to whole body vibration in humans: relationship between wakefulness level and vibration frequencies.

The purpose of this study was to clarify the influence of different vibration frequencies on wakefulness level. Subjects were 7 healthy male university students aged 21.9+/-1.6 years (mean). All students were non-smokers. Three exposure conditions were used (10 Hz vibration, 20 Hz vibration, and no vibration). Whole-body vertical vibration was applied to subjects sitting on a car passenger seat using a whole-body vibration shaker (CV-300, Akashi) at a single frequency (10 or 20 Hz) at an acceleration level of 0.3 ms(-2) r.m.s. for 24 min. The objective wakefulness level based on EEGs was evaluated in terms of the alpha attenuation coefficient (AAC) obtained by the Alpha Attenuation Test (AAT). As parameters of psychological stress, salivary 3-methoxy-4-hydroxyphenylglycol (MHPG) and homovanillic acid (HVA) were used. The subjective wakefulness level was evaluated using a questionnaire based on the Kwansei Gakuin Sleepiness Scale (KSS), which is a scale developed for the Japanese based on the Stanford Sleepiness Scale (SSS). The KSS score, representing the subjective wakefulness level, decreased after the exposure irrespective of the exposure condition, but the decrease was not significant. The AAC, representing the objective wakefulness level, significantly decreased only after vibration exposure (10 Hz/20 Hz) but did not differ between the two vibration frequencies. No significant changes were observed after exposure to whole-body vibration in MHPG or HVA as parameters of vibration-related stress. The AAC decreased after exposure to whole-body vibration (10 Hz/20 Hz), suggesting a decrease in the wakefulness level. However, no differences were observed in the influence of the two different vibration frequencies test.

[Case report of acute death on the 7th day due to exposure to the vapor of the insecticide chlorfenapyr].

We present the case of a 55-year-old male agricultural worker who complained of severe general fatigue and hyperperspiration after exposure to an insecticide vapor. He worked in a tea plantation and used chlorfenapyr, a broad spectrum for harmful insects, without any protective mask or clothes. After one day of insecticide spray work, he gradually began to complain of general fatigue, hyperperspiration, nausea and vomiting. At first, he was diagnosed as being dehydrated and was treated with fluid replacement therapy. Although he received this conservative therapy, there was no effect on the above mentioned symptoms. On the 7th day of the onset of his symptoms, his consciousness level deteriorated rapidly and body temperature exceeded 40 degrees C. No cerebral vascular disease or meningitis was observed. Finally, he died despite intensive care. The findings of the clinical course and laboratory data suggest a clinical diagnosis of acute pesticide poisoning due to exposure to chlorfenapyr vapor. We suggest that agricultural workers should use this insecticide with caution and sufficient protective gear.