Training in cognitive strategies reduces eating and improves food choice.

Obesity rates continue to rise alarmingly, with dire health implications. One contributing factor is that individuals frequently forgo healthy foods in favor of inexpensive, high-calorie, unhealthy foods. One important mechanism underlying these choices is food craving: Craving increases with exposure to unhealthy foods (and food cues, such as advertisements) and prospectively predicts eating and weight. Prior work has shown that cognitive regulation strategies that emphasize the negative consequences of unhealthy foods reduce craving. In Studies 1 and 2, we show that cognitive strategies also increase craving for healthy foods by emphasizing their positive benefits, and change food valuation (willingness to pay) for both healthy and unhealthy foods. In Studies 3 and 4, we demonstrate that brief training in cognitive strategies ("Regulation of Craving Training"; ROC-T) increases subsequent healthy (vs. unhealthy) food choices. This was striking because this change in food choices generalized to nontrained items. Importantly, in Study 5, we show that brief training in cognitive strategies also reduces food consumption by 93-121 calories. Consumed calories correlated with changes in food choice. Finally, in Study 6, we show that the training component of ROC-T is necessary, above and beyond any effect of framing. Across all studies (NTOTAL = 1,528), we find that cognitive strategies substantially change craving and food valuation, and that training in cognitive strategies improves food choices by 5.4-11.2% and reduces unhealthy eating, including in obese individuals. Thus, these findings have important theoretical, public health, and clinical implications for obesity prevention and treatment.

Gastroduodenal Ulcers and ABO Blood Group: the Japan Nurses' Health Study (JNHS).

BACKGROUND: Although several studies have shown that blood type O is associated with increased risk of peptic ulcer, few studies have investigated these associations in Japan. We sought to investigate the association between the ABO blood group and risk of gastroduodenal ulcers (GDU) using combined analysis of both retrospective and prospective data from a large cohort study of Japanese women, the Japan Nurses' Health Study (JNHS; n = 15,019). METHODS: The impact of the ABO blood group on GDU risk was examined using Cox regression analysis to estimate hazard ratios (HRs) and 95% confidence intervals (CI), with adjustment for potential confounders. RESULTS: Compared with women with non-O blood types (A, B, and AB), women with blood type O had a significantly increased risk of GDU from birth (multivariable-adjusted HR 1.18; 95% CI, 1.04-1.34). Moreover, the highest cumulative incidence of GDU was observed in women born pre-1956 with blood type O. In a subgroup analysis stratified by birth year (pre-1956 or post-1955), the multivariable-adjusted HR of women with blood type O was 1.22 (95% CI, 1.00-1.49) and 1.15 (95% CI, 0.98-1.35) in the pre-1956 and post-1955 groups, respectively. CONCLUSION: In this large, combined, ambispective cohort study of Japanese women, older women with blood type O had a higher risk of developing GDU than those with other blood types.

Uterine leiomyomata: a retrospective study of correlations with hypertension and diabetes mellitus from the Japan Nurses' Health Study.

We performed a scrutiny survey of self-reported uterine leiomyomata (UL) to investigate the associations of parental history with hypertension and personal history of hypertension in the UL cases in Japanese women. Questionnaires that included items on the sites of UL determined by imaging techniques and surgical procedure were mailed to 2015 women with a self-reported UL at a baseline survey of the Japan Nurses' Health Study (n = 15,019). We found that women with a past history and a maternal history of hypertension had an increase in their risk of UL. A maternal history of hypertension was significantly associated with an increase in the risk of UL in women without a past history of hypertension but not in the women with a past history of hypertension. A past history and a parental history of diabetes mellitus were not associated with an increase in the risk of UL. Women of reproductive age with a maternal history of hypertension may be at a higher risk for hypertension and UL. Impact Statement What is already known on this subject? A positive association of uterine leiomyomata (UL) with a past history of hypertension has been found but the association of a parental history of hypertension with UL has not yet been clarified. What do the results of this study add? Maternal hypertension, as well as a personal history of hypertension, was associated with an increased risk of UL and a past history and a parental history of diabetes mellitus were not associated with an increase in the risk of UL. What are the implications of these findings for clinical practice and/or further research? Women of a reproductive age with a maternal history of hypertension may be at a higher risk for hypertension and UL.

Blood pressure-lowering effect of Shinrin-yoku (Forest bathing): a systematic review and meta-analysis.

BACKGROUND: Shinrin-yoku (experiencing the forest atmosphere or forest bathing) has received increasing attention from the perspective of preventive medicine in recent years. Some studies have reported that the forest environment decreases blood pressure. However, little is known about the possibility of anti-hypertensive applications of Shinrin-yoku. This study aimed to evaluate preventive or therapeutic effects of the forest environment on blood pressure. METHODS: We systematically reviewed the medical literature and performed a meta-analysis.Four electronic databases were systematically searched for the period before May 2016 with language restriction of English and Japanese. The review considered all published, randomized, controlled trials, cohort studies, and comparative studies that evaluated the effects of the forest environment on changes in systolic blood pressure. A subsequent meta-analysis was performed. RESULTS: Twenty trials involving 732 participants were reviewed. Systolic blood pressure of the forest environment was significantly lower than that of the non-forest environment. Additionally, diastolic blood pressure of the forest environment was significantly lower than that of the non-forest environment. CONCLUSIONS: This systematic review shows a significant effect of Shinrin-yoku on reduction of blood pressure.

The Neurobiology of Giving Versus Receiving Support: The Role of Stress-Related and Social Reward-Related Neural Activity.

OBJECTIVES: There is a strong association between supportive ties and health. However, most research has focused on the health benefits that come from the support one receives while largely ignoring the support giver and how giving may contribute to good health. Moreover, few studies have examined the neural mechanisms associated with support giving or how giving support compares to receiving support. METHOD: The current study assessed the relationships: a) between self-reported receiving and giving social support and vulnerability for negative psychological outcomes and b) between receiving and giving social support and neural activity to socially rewarding and stressful tasks. Thirty-six participants (mean [standard deviation] age = 22.36 [3.78] years, 44% female) completed three tasks in the functional magnetic resonance imaging scanner: 1) a stress task (mental arithmetic under evaluative threat), b) an affiliative task (viewing images of close others), and c) a prosocial task. RESULTS: Both self-reported receiving and giving social support were associated with reduced vulnerability for negative psychological outcomes. However, across the three neuroimaging tasks, giving but not receiving support was related to reduced stress-related activity (dorsal anterior cingulate cortex [r = -0.27], left [r = -0.28] and right anterior insula [r = -0.33], and left [r = -0.32] and right amygdala [r = -0.32]) to a stress task, greater reward-related activity (left [r = 0.42] and right ventral striatum [VS; r = 0.41]) to an affiliative task, and greater caregiving-related activity (left VS [r = 0.31], right VS [r = 0.31], and septal area [r = 0.39]) to a prosocial task. CONCLUSIONS: These results contribute to an emerging literature suggesting that support giving is an overlooked contributor to how social support can benefit health.

Risk profiles for endometriosis in Japanese women: results from a repeated survey of self-reports.

BACKGROUND: The prevalence and risk factors for endometriosis may differ according to diagnosis methodologies, such as study populations and diagnostic accuracy. We examined risk profiles in imaging-diagnosed endometriosis with and without surgical confirmation in a large population of Japanese women, as well as the differences in risk profiles of endometriosis based on history of infertility. METHODS: Questionnaires that included items on sites of endometriosis determined by imaging techniques and surgical procedure were mailed to 1025 women who self-reported endometriosis in a baseline survey of the Japan Nurses' Health Study (n = 15 019). RESULTS: Two hundred and ten women had surgically confirmed endometriosis (Group A), 120 had imaging-diagnosed endometriosis without a surgical procedure (Group B), and 264 had adenomyosis (Group C). A short menstrual cycle at 18-22 years of age and cigarette smoking at 30 years of age were associated with significantly increased risk of endometriosis (Group A plus Group B), while older age was associated with risk of adenomyosis (Group C). In women with a history of infertility, a short menstrual cycle was associated with a significantly increased risk of endometriosis in both Group A and Group B, but risk profiles of endometriosis were different between Group A and Group B in women without a history of infertility. CONCLUSIONS: Women with surgically confirmed endometriosis and those with imaging-diagnosed endometriosis without surgery have basically common risk profiles, but these risk profiles are different from those with adenomyosis. The presence of a history of infertility should be taken into consideration for evaluation of risk profiles.

Association between cancer screening behavior and family history among Japanese women.

OBJECTIVE: To examine lifestyle habits and cancer screening behavior in relation to a family history of cancer among Japanese women. METHODS: A cross-sectional study was conducted based on baseline data from the Japan Nurses' Health Study collected from June 2001 to March 2007. Participants were 47,347 female nurses aged 30-59 years residing in 47 prefectures in Japan. We compared lifestyle habits and the utilization of cancer screenings (cervical and breast) between women with and without a family history of the relevant cancer. RESULTS: Although there were no differences in lifestyle habits with the exception of smoking status, women with a family history of uterine cancer were more likely to have undergone cervical cancer screenings (p<0.01). Women with a family history of breast cancer were also more likely to have undergone breast cancer screenings regardless of their age (p<0.01), but lifestyle behaviors did not differ. Among women with a family history of uterine cancer, those with a sister history were more likely to have undergone not only cervical (OR, 1.89; 95% CIs, 1.39-2.58), but also breast cancer screenings (OR, 1.54; 95% CIs 1.13-2.09). CONCLUSION: Having a family history of cancer was associated with cancer screening behavior, but not health promotive behaviors.

Use of Dietary Supplements among Japanese Female Nursing Professionals.

The use of dietary supplements has become a common way to maintain good health. This study evaluated the status of supplement use and supplement user characteristics among participants from the Japan Nurses' Health Study, which comprised a cohort of Japanese female nursing professionals. A questionnaire survey covering the use of vitamins and supplements was conducted. Supplements were classified according to their constituents and formulations. Logistic regression analyses were performed to determine the characteristics of supplement users. Results were as follows. There were 4,017 supplement users (34.4% of 11,665 valid answers). The supplement types used were: vitamins (n=2,655), minerals (n=1,121), amino acids and proteins (n=139), botanical products (n=714), animal by-products (n=849), herbal medicines (n=152), nutritional drinks (n=19), others (n=117), and unclassified supplements (n=320). Logistic regression analyses showed that supplement use was significantly associated with age and body mass index, and there were significantly higher proportions of supplement users among pregnant women, black tea drinkers, soy milk consumers, and lactobacillus beverage drinkers. In conclusion, the overall percentage of supplement users was 34.4%. A high prevalence of supplement use was observed among older, non-obese, and pregnant participants, and those who paid more attention to their health. The prevalence of supplement users was significantly higher among those who habitually drank black tea, soy milk, and lactobacillus beverages, suggesting participants used supplements to maintain their health or prevent diseases based on high health consciousness.

Health status and lifestyle factors as predictors of depression in middle-aged and elderly Japanese adults: a seven-year follow-up of the Komo-Ise cohort study.

BACKGROUND: Depression is a common mental disorder. Several studies suggest that lifestyle and health status are associated with depression. However, only a few large-scale longitudinal studies have been conducted on this topic. METHODS: The subjects were middle-aged and elderly Japanese adults between the ages of 40 and 69 years. A total of 9,650 respondents completed questionnaires for the baseline survey and participated in the second wave of the survey, which was conducted 7 years later. We excluded those who complained of depressive symptoms in the baseline survey and analyzed data for the remaining 9,201 individuals. In the second-wave survey, the DSM-12D was used to determine depression. We examined the risks associated with health status and lifestyle factors in the baseline survey using a logistic regression model. RESULTS: An age-adjusted analysis showed an increased risk of depression in those who had poor perceived health and chronic diseases in both sexes. In men, those who were physically inactive also had an increased risk of depression. In women, the analysis also showed an increased risk of depression those with a BMI of 25 or more, in those sleeping 9 hours a day or more and who were current smokers. A multivariate analysis showed that increased risks of depression still existed in men who had chronic diseases and who were physically inactive, and in women who had poor perceived health and who had a BMI of 25 or more. CONCLUSIONS: These results suggest that lifestyle and health status are risk factors for depression. Having a chronic disease and physical inactivity were distinctive risk factors for depression in men. On the other hand, poor perceived health and a BMI of 25 or more were distinctive risk factors for depression in women. Preventive measures for depression must therefore take gender into account.

Two scene navigation systems dissociated by deliberate versus automatic processing.

Successfully navigating the world requires avoiding boundaries and obstacles in one's immediately-visible environment, as well as finding one's way to distant places in the broader environment. Recent neuroimaging studies suggest that these two navigational processes involve distinct cortical scene processing systems, with the occipital place area (OPA) supporting navigation through the local visual environment, and the retrosplenial complex (RSC) supporting navigation through the broader spatial environment. Here we hypothesized that these systems are distinguished not only by the scene information they represent (i.e., the local visual versus broader spatial environment), but also based on the automaticity of the process they involve, with navigation through the broader environment (including RSC) operating deliberately, and navigation through the local visual environment (including OPA) operating automatically. We tested this hypothesis using fMRI and a maze-navigation paradigm, where participants navigated two maze structures (complex or simple, testing representation of the broader spatial environment) under two conditions (active or passive, testing deliberate versus automatic processing). Consistent with the hypothesis that RSC supports deliberate navigation through the broader environment, RSC responded significantly more to complex than simple mazes during active, but not passive navigation. By contrast, consistent with the hypothesis that OPA supports automatic navigation through the local visual environment, OPA responded strongly even during passive navigation, and did not differentiate between active versus passive conditions. Taken together, these findings suggest the novel hypothesis that navigation through the broader spatial environment is deliberate, whereas navigation through the local visual environment is automatic, shedding new light on the dissociable functions of these systems.

Distinct regions of the striatum underlying effort, movement initiation and effort discounting.

The ventral striatum is believed to encode the subjective value of cost-benefit options; however, this effect has notably been absent during choices that involve physical effort. Previous work in freely moving animals has revealed opposing striatal signals, with greater response to increasing effort demands and reduced responses to rewards requiring effort. Yet, the relationship between these conflicting signals remains unknown. Using functional magnetic resonance imaging with a naturalistic maze-navigation paradigm, we identified functionally segregated regions within the ventral striatum that separately encoded effort activation, movement initiation and effort discounting of rewards. In addition, activity in regions associated with effort activation and discounting oppositely predicted striatal encoding of effort during effort-based decision-making. Our results suggest that the dorsomedial region hitherto associated with action may instead represent the cost of effort and raise fundamental questions regarding the interpretation of striatal 'reward' signals in the context of effort demands. This has implications for uncovering the neural architecture underlying motivated behaviour.

Association of trajectory of body mass index with knee pain risk in Japanese middle-aged women in a prospective cohort study: the Japan Nurses' Health Study.

OBJECTIVES: To investigate whether body mass index (BMI) trajectory, lifestyle and reproductive factors are associated with knee pain risk among middle-aged women. DESIGN: Prospective study of the Japan Nurses' Health Study (JNHS). SETTING: The JNHS investigates the health of female nurses in Japan. Biennial follow-up questionnaires are mailed to the participants. PARTICIPANTS: The 7434 women aged over 40 years who responded to the 10-year self-administered follow-up questionnaire. PRIMARY OUTCOME MEASURE: Self-reported knee pain at the 10-year follow-up was the primary outcome. We analysed BMI (normal or overweight) trajectory data from a baseline survey to the 10-year follow-up survey using group-based trajectory modelling. Exposure measurements were BMI trajectory, BMI at age 18 years, lifestyle variables and reproductive history. RESULTS: BMI trajectories from baseline to the 10-year follow-up were divided into four groups: remained normal, remained overweight, gained weight or lost weight. At the 10-year follow-up, 1281 women (17.2%) reported knee pain. Multivariable logistic regression analysis revealed that compared with the remained normal group, multivariable-adjusted ORs (95% CI) of knee pain were 1.93 (1.60 to 2.33) for the remained overweight group, 1.60 (1.23 to 2.08) for the gained weight group and 1.40 (0.88 to 2.21) for the lost weight group. The attributable risk percent (95% CI) of the remained overweight group was 48.1% (37.3% to 57.0%) compared with the reference group of remained normal. Alcohol intake at baseline was significantly associated with knee pain. CONCLUSIONS: The lost weight group had a lower risk than the remained overweight group and the gained weight group and did not carry statistically significant risks for knee pain. Weight reduction and maintaining a normal BMI in middle age was important for preventing knee pain in women.

Regulation of Craving and Negative Emotion in Alcohol Use Disorder.

BACKGROUND: Alcohol use disorder (AUD) is a chronic, relapsing condition with poor treatment outcomes. Both alcohol craving and negative affect increase alcohol drinking, and-in healthy adults-can be attenuated using cognitive strategies, which rely on the prefrontal cortex (PFC). However, AUD is associated with cognitive impairments and PFC disruptions. Thus, we tested whether individuals with AUD can successfully recruit the PFC to effectively regulate craving and negative emotions, whether neural mechanisms are shared between the two types of regulation, and whether individual differences influence regulation success. METHODS: During functional magnetic resonance imaging, participants with AUD completed the regulation of craving task (n = 17) that compares a cue-induced craving condition with an instructed regulation condition. They also completed the emotion regulation task (n = 15) that compares a negative affect condition with an instructed regulation condition. Regulation strategies were drawn from cognitive behavioral therapy treatments for AUD. Self-reported craving and negative affect were collected on each trial. RESULTS: Individuals with AUD effectively regulated their craving and negative affect when instructed to do so using cognitive behavioral therapy-based strategies. Regulation was associated with recruitment of both common and distinct PFC regions across tasks, as well as with reduced activity in regions associated with craving and negative affect (e.g., ventral striatum, amygdala). Effective regulation of craving was associated with negative alcohol expectancies. CONCLUSIONS: Both common and distinct regulatory systems underlie regulation of craving and negative emotions in AUD, with notable individual differences. This has important implications for AUD treatment.

A proper reference metabolic equivalent value to assess physical activity intensity in Japanese female nurses.

BACKGROUND: Various questionnaires have been developed to assess physical activity, but only a few simple questionnaires are suitable for self-administration in large groups of midlife working women. This study examined the usefulness of the Japan Nurses' Health Study (JNHS) questionnaire for self-administered physical activity surveys. METHODS: The JNHS physical activity questionnaire consisted of items covering seven degrees of intensity. The metabolic equivalents (METs) for the physical activity intensity of the questionnaire were estimated from energy expenditure as measured by a uniaxial accelerometer with the Markov Chain Monte Carlo (MCMC) simulation. The estimated METs were then assigned to the JNHS baseline survey data, and the total energy expenditure (TEE) and the time spent performing ≥3 METs hour of physical activity, called moderate to vigorous intensity physical activity (MVPA), were calculated. RESULTS: For working situations, application of the MCMC simulation resulted in estimated reference values of 1.2 METs for "sitting work", 1.6 METs for "standing work", 1.8 METs for "walking work", and 4.5 METs for "heavy work". For non-working situations, the estimated values were 1.1 METs for sedentary time, 2.4 METs for "moderate physical activity", 4.4 METs for "vigorous physical activity", and 9.4 METs for "very vigorous physical activity". When these estimated METs were used, the mean TEE/day was 1808 kcal. This corresponded to - 3.0% of the TEE/day generated by the accelerometer. These estimated MET values showed similar results as a previous study measuring activity using the doubly-labeled water method. The number of hours per week of MVPA significantly decreased with age, which is also consistent with previous findings. CONCLUSIONS: Estimated reference MET values in this study were similar to those in previous studies of Japanese women. The JNHS questionnaire is therefore useful for epidemiological surveys of midlife working women because it assigns estimated MET values as physical activity intensities.

Predictive validity of the total health index for all-cause mortality assessed in the Komo-Ise cohort.

BACKGROUND: The Total Health Index (THI), a self-administered questionnaire developed in Japan, is used for symptom assessment and stress management of employees and others; however, it has not been reported whether it can predict mortality risk. METHODS: The THI, with 12 primary and 5 secondary scales, was applied to a cohort consisting of middle-aged residents in Japan. This study, called the Komo-Ise cohort study, was started in 1993. The scale scores were related to 481 deaths from all causes among 10,816 residents over 93 months. The statistics were tested by the Cox hazard model and adjusted for three background variables (sex, age, and district where the subject resided). RESULTS: Five of the scales [depression and aggression (primary scales), and psychosomatics, neurotics, and schizophrenics (secondary scales)] indicated significant hazard ratios for mortality. The lowest quintile group of the aggression scale score had the largest hazard ratio of 2.58, compared with the middle quintile group (95% confidence interval: 1.88-3.52). The psychosomatics, neurotic scales and depression scales also had a minimum hazard ratio in the middle quintile group. One of the secondary scales, T1, which represents a somatoform disorder, had a significant linear relationship with the mortality risk, although its proportionality with the cumulative mortality rates was not satisfactory. CONCLUSIONS: Five scales of the THI were significantly related to mortality risk in the Komo-Ise cohort, which could be used for score evaluation and in the personal health advice system of the THI.

Physical symptoms and psychological health status by the type of job.

BACKGROUND: The physical symptoms and mental health status of 3,447 men working in a dairy product company were evaluated by a health questionnaire, the Todai Health Index (THI). The purpose of this study is to determine the relationship between job content and subjective health status. METHOD: The authors conducted a cross-sectional study. Thirty-three branches of the company are distributed throughout Japan. The subjects ranged in age from 18 to 59 years old. The THI is composed of 130 questions and each subject's physical and mental health status was evaluated based on the scores in 13 specific scales. The subjects' jobs were classified into three categories: 1 production process work; 2 clerical or technical work; 3 transportation or sales work. Subjects grouped into the clerical or technical work category were set as the control group, because the authors speculated that the lowest workload was observed in group of clerical or technical work. RESULTS: The scores in each of the THI scales were compared among workers in the three job categories stratified by the age group (10-year age groups). The transportation or sales workers began to show high scores for irregularity of lifestyle from their 30's, and this was maintained until subjects' retirement from the company. In addition, the same group also began to show higher scores for physical symptoms, such as vague complaints, respiratory complaints, and eye complaints from their 40's and higher scores for mouth and evacuation and digestive complaints from their 50's. CONCLUSIONS: Transportation or sales workers should receive adequate health care to prevent a high prevalence of physical and/or illness.

[Perceived health and its correlation with depression and subjective symptoms of nurses and care workers].

The objective of this study was to identify psychological and physical health characteristics of nurses and care workers employed at a psychiatric hospital and to characterize depressive symptoms by means of correlation analysis. Subjects were 89 nurses and 78 care workers employed at a psychiatric and rehabilitation hospital in Gunma Prefecture, Japan. They responded to a structured questionnaire, the Total Health Index (THI). Mean scores of the four THI scales, Vague Complaints, Respiratory, Depression and Neurotics, of all the 167 study subjects were significantly higher than those of three reference groups. The smoking rate was almost two times higher than that of adult Japanese women. These results may be attributed to psychological stress these workers suffer in their daily human service. However, we found little difference in THI scores based on shift work or responsibilities (nursing vs. care taking). Our findings suggest that it is necessary to provide these workers some support for stress management. THI scores that correlated most strongly with the Depression score were Mental Instability, Irregularity of Life, Irritability, and Vague Complaints (correlation coefficients were 0.75, 0.54, 0.53, and 0.52, respectively). THI scores that correlated most weakly with the Depression score were Digestive, Respiratory, and Mouth and Anal (correlation coefficients were 0.35, 0.34, and 0.32, respectively). Depression in our subjects appeared to be related exclusively to vague psychological symptoms rather than organ-specific symptoms.

Agricultural workers in a cohort of middle-aged Japanese women showed better health status than did women with other occupations.

Objective: This study investigated the relationship between occupations and health status to obtain an overall understanding of a cohort of Japanese middle-aged women, including unemployed women, who comprised approximately 30% of the sample. Participants and Methods: Participants of this study were 4,454 women aged 40-69 years, classified into the following five groups based on their occupation: unemployed, 1,432; agriculture, 439; self-employed, 1,596; white collared, 793; and blue collared, 194. Participants' perceived health was assessed using a symptoms checklist called the Todai Health Index (THI, later renamed as the Total Health Index) in a baseline survey conducted in 1993. The mortality risk of the participants was assessed using the Cox's Proportional Hazards Model. Results: The means of the percentile values on the Total Scale 1 in the THI were as follows: agriculture, 43.7; unemployed, 50.8; self-employed, 52.5; white collared, 53.0; and blue collared, 56.1, with lower percentile values indicating better perceived health. The results showed that women engaged in agriculture were in significantly better health than were those in the other four occupations. The hazard ratios (HRs) and 95% confidence intervals of the occupational groups adjusted for age, area of residence, and Total Scale 1 scores were as follows: agriculture (reference group), 1; white collared, 1.16 (0.77-1.74); self-employed, 1.25 (0.87-1.78); unemployed, 1.27 (0.91-1.77); and blue collared, 1.50 (0.86-2.60). Conclusions: Women engaged in agriculture had a significantly higher tendency to have a better health status on the THI as compared to those from the other four occupational groups, and they exhibited the lowest HR as compared to their counterparts, though not statistically significant. We concluded that the perceived health status of unemployed women was similar to that of women engaged in agriculture.

Design of the Japan Nurses' Health Study: a prospective occupational cohort study of women's health in Japan.

The Japan Nurses' Health Study (JNHS) is a prospective occupational cohort study investigating the effects of lifestyle and healthcare practices on women's health. It was initiated in 2001, with a six-year entry period and a proposed ten-year follow-up. Participants comprise female registered nurses, licensed practical nurses, public health nurses, and midwives, aged 25 yr or over at the baseline survey. Participants were recruited in cooperation with the Japanese Nursing Association and the Japan Menopause Society. A self-administered baseline questionnaire was distributed, requesting demographic information, lifestyle factors, pharmaceutical drug use, physical condition, reproductive health, and disease history. A total of 49,914 women from all 47 prefectures in Japan responded to the baseline survey. Among them, approximately 18,000 agreed to be followed-up, and returned signed informed-consent sheets, together with their completed baseline questionnaires. Changes in lifestyle, healthcare, incidence of disease, and health outcomes over time will now be studied. The cohort receives annual JNHS newsletters and biennial follow-up questionnaires by mail.

Prevalence of diseases and statistical power of the Japan Nurses' Health Study.

The Japan Nurses' Health Study (JNHS) is a long-term, large-scale cohort study investigating the effects of various lifestyle factors and healthcare habits on the health of Japanese women. Based on currently limited statistical data regarding the incidence of disease among Japanese women, our initial sample size was tentatively set at 50,000 during the design phase. The actual number of women who agreed to participate in follow-up surveys was approximately 18,000. Taking into account the actual sample size and new information on disease frequency obtained during the baseline component, we established the prevalence of past diagnoses of target diseases, predicted their incidence, and calculated the statistical power for JNHS follow-up surveys. For all diseases except ovarian cancer, the prevalence of a past diagnosis increased markedly with age, and incidence rates could be predicted based on the degree of increase in prevalence between two adjacent 5-yr age groups. The predicted incidence rate for uterine myoma, hypercholesterolemia, and hypertension was > or =3.0 (per 1,000 women, per year), while the rate of thyroid disease, hepatitis, gallstone disease, and benign breast tumor was predicted to be > or =1.0. For these diseases, the statistical power to detect risk factors with a relative risk of 1.5 or more within ten years, was 70% or higher.