Psychological attitudes and risk of breast cancer in Japan: a prospective study

Subjective well-being predicts Covid-19 risk in the elderly: a case-control study

BACKGROUND

Covid-19 is a serious public health concern. Previous studies have shown that although there are concerns about the subjective well-being (SWB) of older people in the Covid period, the link between SWB and the risk of Covid-19 is still unclear. This study aimed to investigate the predictive effect of SWB on the Covid-19 risk in the elderly as well as the determinants of SWB.

METHODS

This case-control study was performed in the elderly over 60 years of age. The case group consisted of all hospitalized patients with COVID-19 and the control group from the same population with no history of COVID-19 matched by age, sex, and place of residence. Data collection tools included a demographic questionnaire and SWB scale of Keyes and Magyarmo to measure emotional, psychological and social well-being. All data were analyzed via SPSS and STATA software. Multiple binary logistic regression was run to predict the probability of Covid-19 risk on the values of total SWB and its three subscales and multiple linear regression to identify SWB determinants.

RESULTS

The results showed that increasing one unit in total SWB reduces the risk of Covid-19 by 4% (OR = 0.969, CI = 0.947-0.991, p = 0.006). Emotional well-being with 0.823 had the highest odds ratio for predicting Covid-19 risk, followed by social well-being with an odds ratio of 0.981. Increasing age and education, better economic status, marriage against celibacy, lack of comorbidity, and a better understanding of own health were associated with greater SWB.

DISCUSSION

This study provides evidence for the protective effect of SWB on Covid-19 risk. To promote SWB, we need to focus on the elderly with higher financial worries and comorbidities, as well as those with less education, health perception and SWB. Therefore, it will be important for the elderly to determine strategies to improve SWB during the epidemic.

Prognostic Value of Negative Emotions on the Incidence of Breast Cancer: A Systematic Review and Meta-Analysis of 129,621 Patients with Breast Cancer

Breast cancer (BC) is one of the common malignant tumors in women and affects 1.6 million new cases globally each year. Investigators have recently found that negative emotions (NEs) and their impacts have greatly influenced the incidence and risk of BC. The present study aims to provide an association between NEs and the incidence of BC with possible risk factors. A total of 9343 studies were screened; nine studies met all inclusion criteria that were considered for the meta-analysis. The qualitative studies were measured by the Newcastle-Ottawa Scale; the observational studies were included with relative risks (RR) and corresponding 95% confidence intervals (CI). Besides the NEs and BC, the possible risk factors were evaluated. We analyzed data from 129,621 women diagnosed with NEs of which 2080 women were diagnosed with BC and their follow-up year ranges were from 4–24 years. NEs were significantly (p < 0.0001) associated with a higher incidence of BC with RR = 1.59, 95% CI:1.15–2.19, with other high-risk factors including, geographical distribution, emotion types, standard diagnosis of NEs, and follow-up duration. This study suggests that NEs significantly increase the risk for the incidence of BC, which can be supportive of the prognosis of the disease.

Social capital is associated with improved subjective well-being of older adults with chronic non-communicable disease in six low- and middle-income countries

BACKGROUND

Non-communicable diseases (NCDs) are increasingly contributing to the morbidity and mortality burden of low and-middle income countries (LMIC). Social capital, particularly participation has been considered as a possible protective factor in the prevention and management of chronic conditions. It is also largely shown to have a negative effect on the well-being of patients. The current discourse on the well-being of individuals with NCDs is however focused more on a comparison with those with no NCDs without considering the difference between individuals with one chronic condition versus those with multiple chronic conditions (MCC).

METHOD AND OBJECTIVE

We employed a multinomial logit model to examine the effect of social capital, particularly social participation, on the subjective well-being (SWB) of older adults with single chronic condition and MCC in six LMIC.

FINDINGS

Social capital was associated with increased subjective well-being of adults in all the six countries. The positive association between social capital and subjective well-being was higher for those with a single chronic condition than those with multiple chronic conditions in India and South Africa. Conversely, an increase in the likelihood of having higher subjective well-being as social capital increased was greater for those with multiple chronic conditions compared to those with a single chronic condition in Ghana.

DISCUSSION

The findings suggest that improving the social capital of older adults with chronic diseases could potentially improve their subjective well-being. This study, therefore, provides valuable insights into potential social determinants of subjective well-being of older adults with chronic diseases in six different countries undergoing transition. Additional research is needed to determine if these factors do in fact have causal effects on SWB in these populations.

Multiple exposure to environmental factors and variations in CYP27B1 and the microRNA-binding site of IL-13 are associated with breast cancer risk

Purpose

Several molecular epidemiology studies have evidenced an association of environmental factors and genetic polymorphisms with breast cancer (BC) risk. However, most have considered the functions of a single element rather than combined effects.

Methods

This case‐control study of 693 newly‐diagnosed BC cases and 714 cancer‐free controls evaluated the effect of multiple exposures to environmental factors and polymorphisms in CYP27B1 and IL‐13 on BC risk. Genotypes were detected using TaqMan genotyping. Combinations and interactions were analyzed using cross‐over analysis and multivariate logistic regression. Combining exposure models were assessed using classification and regression tree and multivariate logistic regression analyses.

Results

No significant independent association was observed for any polymorphism in CYP27B1 or IL‐13 with the risk of BC. However, significant combined effects were noted for ≥1 time/wk physical activity with rs10877012 (adjusted odds ratio [OR_adj] = 0.21, 95% confidence interval [CI] = 0.11‐0.39) and rs4646536 (OR_adj = 0.21, 95% CI = 0.11‐0.39) in CYP27B1. Furthermore, taking garlic ≥4 times/wk, ≥1 time/wk physical activity, and a psychological index score ≥33 all displayed significant combined effects with three IL‐13 polymorphisms. These relationships remained significant after Bonferroni correction for multiple comparisons. Combining exposure models indicated that compared with consuming garlic ≥4 times/wk, five models (model 5, OR_adj = 2.94, 95% CI = 1.07‐8.06; model 6, OR_adj = 10.26, 95% CI = 5.81‐18.10; model 7, OR_adj = 5.05, 95% CI = 2.78‐9.17; model 8, OR_adj = 3.95, 95% CI = 2.79‐5.58; and model 9, OR_adj = 7.97, 95% CI = 5.26‐12.07) showed a significant increased risk.

Conclusions

Our findings suggest that personalized adjustments to diet and behavioral patterns may aid BC prevention in variant carriers of CYP27B1 and IL‐13.

Risk prediction for breast Cancer in Han Chinese women based on a cause-specific Hazard model

Background

Considering the lack of efficient breast cancer prediction models suitable for general population screening in China. We aimed to develop a risk prediction model to identify high-risk populations, to help with primary prevention of breast cancer among Han Chinese women.

Methods

A cause-specific competing risk model was used to develop the Han Chinese Breast Cancer Prediction model. Data from the Shandong Case-Control Study (328 cases and 656 controls) and Taixing Prospective Cohort Study (13,176 participants) were used to develop and validate the model. The expected/observed (E/O) ratio and C-statistic were calculated to evaluate calibration and discriminative accuracy of the model, respectively.

Results

Compared with the reference level, the relative risks (RRs) for highest level of number of abortions, age at first live birth, history of benign breast disease, body mass index (BMI), family history of breast cancer, and life satisfaction scores were 6.3, 3.6, 4.3, 1.9, 3.3, 2.4, respectively. The model showed good calibration and discriminatory accuracy with an E/O ratio of 1.03 and C-statistic of 0.64.

Conclusions

We developed a risk prediction model including fertility status and relevant disease history, as well as other modifiable risk factors. The model demonstrated good calibration and discrimination ability.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5321-1) contains supplementary material, which is available to authorized users.

ROK study-C (Rainbow of KIBOU study-colorectum): a colorectal cancer survivor cohort study on food, nutrition, physical activity, psychosocial factors and its influences on colorectal cancer recurrence, survival and quality of life in Japan

BACKGROUND

Many studies have shown that lifestyle factors such as diet, physical activity are related to the incidence of cancer. However, there are few studies on the association between lifestyle factors and cancer prognosis. To investigate the influence of lifestyle factors and psychosocial factors on prognosis, we started a prospective study of women with breast cancer, the Rainbow of KIBOU study-Breast (ROK Study-B) in 2007. As of February 2018, more than 6300 women have been enrolled, thus making this one of the world's largest cancer patient cohort studies. Based on the know-how obtained from this study, we started another new cohort study for colorectal cancer patient (ROK Study-C).

METHODS

The ROK Study-C is a prospective observational study for colorectal cancer survivors at the National Cancer Center Hospital. Participants fill in several self-administrated questionnaires about lifestyle, psychosocial factors (including posttraumatic growth and benefit finding, support), and quality of life (QOL) 5 times in total: at diagnosis, 3 and 6 months, 1 and 5 years after surgery. CT-scans will be collected to assess body composition and obesity. We also use blood and cancer tissue from the Biobank. The primary endpoint is disease-free survival. The secondary endpoints are overall survival and health-related QOL. The planned sample size is 2000 and the follow-up period is 5 years after the last enrollment.

DISCUSSION

Recruitment began in December 2015 and the study is still ongoing. The ROK Study-C will contribute to improvements in patient prognosis and yield important evidence for colorectal cancer survivorship.

Psychological Well-being and Physical Health: Associations, Mechanisms, and Future Directions

A paradigm shift in public health and medicine has broadened the field from a singular focus on the ill effects of negative states and psychopathology to an expanded view that examines protective psychological assets that may promote improved physical health and longevity. We summarize recent evidence of the link between psychological well-being (including positive affect, optimism, life meaning and purpose, and life satisfaction) and physical health, with particular attention to outcomes of mortality and chronic disease incidence and progression. Within this evolving discipline there remain controversies and lessons to be learned. We discuss measurement-related challenges, concerns about the quality of the evidence, and other shortcomings in the field, along with a brief discussion of hypothesized biobehavioral mechanisms involved. Finally, we suggest next steps to move the field forward.

A case-control study on risk factors of breast cancer in Han Chinese women

This study aimed to investigate risk factors associated with breast cancer among Han Chinese women in northern and eastern China. A matched case-control study involving 1489 patients with breast cancer and 1489 controls was conducted across 21 hospitals in 11 provinces in China, from April 2012 to April 2013. We developed a structured questionnaire to record information from face-to-face interviews with participants. Student's t-tests, Pearson's chi-square tests, and univariate and multivariate conditional logistic regression analyses were used to identify variables with significant differences between the case and control groups. Ten variables were identified (P<0.05): location, economic status, waist-to-hip ratio, menopause, family history of breast cancer, present life satisfaction, sleep satisfaction, milk products, behavior prevention scores, and awareness of breast cancer. We identified a comprehensive range of factors related to breast cancer, among which several manageable factors may contribute to breast cancer prevention. Further prospective studies concerning psychological interventions, sleep regulation, health guidance, and physical exercise are required. A screening model for high-risk populations should be put on the agenda.

The interaction between individualism and wellbeing in predicting mortality: Survey of Health Ageing and Retirement in Europe

The link between greater wellbeing and longevity is well documented. The aim of the current study was to test whether this association is consistent across individualistic and collectivistic cultures. The sample consisted of 13,596 participants from 11 European countries, each of which was assigned an individualism score according to Hofstede et al.'s (Cultures and organizations: software of the mind, McGraw Hill, New York, 2010) cultural dimension of individualism. We tested whether individualism moderated the cross-sectional association between wellbeing and self-rated health or the longitudinal association between wellbeing and mortality risk. Our analysis revealed a significant interaction between individualism and wellbeing such that the association between wellbeing and self-rated health or risk of mortality from cardiovascular disease was stronger in more individualistic countries. However, the interaction between wellbeing and individualism was not significant in analysis predicting all-cause mortality. Further prospective studies are needed to confirm our finding and to explore the factors responsible for this culturally dependent effect.

The influence of personality and perceived stress on the development of breast cancer: 20-year follow-up of 29,098 Japanese women

Breast cancer is the most common cancer in women. However, it remains unproven whether psychological factors have an influence on breast cancer incidence. In our earlier study, subjects possessing two personality traits, decisiveness and "ikigai" (a Japanese word meaning something that makes one's life worth living), showed a significantly lower risk of developing breast cancer, although no psychological factors have been convincingly demonstrated to have an influence on breast cancer development in other studies. Therefore, we conducted this follow-up analysis to confirm the association between breast cancer incidence and psychological traits, using the final dataset of a large-scale prospective cohort study in Japan. We identified 209 cases of incident breast cancer out of a maximum 21-year follow-up of 29,098 Japanese women. Cox proportional hazard regression analysis, adjusted for the same potential confounders used in our previous study, did not reveal any significant relationships between breast cancer incidence and four psychological traits: having "ikigai", decisiveness, ease of anger arousal, and perceived stress. Our finding is consistent with previous studies, and suggests that the psychological traits are unlikely to be an important risk factor for breast cancer.

Wellbeing and Arthritis Incidence: the Survey of Health, Ageing and Retirement in Europe

BACKGROUND

A number of studies provide evidence for an association between psychosocial factors and risk of incident arthritis. Current evidence is largely limited to the examination of negative factors such as perceived stress, but positive factors such as subjective wellbeing may also play a role.

PURPOSE

The purpose of the current study was to investigate whether people with higher subjective wellbeing have a lower risk of developing arthritis.

METHODS

We used Cox proportional hazards regression to examine the prospective relationship between wellbeing (measured using the CASP-12) and incidence of arthritis over a 9-year period. The sample consisted of 13,594 participants aged ≥50 years from the Survey of Health, Ageing and Retirement in Europe.

RESULTS

There was a significant association between greater wellbeing and reduced incident arthritis that was stronger at younger ages. In sex-adjusted analyses, for a standard deviation increase in CASP-12 score, the hazard ratios (95 % confidence intervals) for incident arthritis in people aged <65 and ≥65 years were 0.73 (0.69-0.77) and 0.80 (0.77-0.85), respectively. After further adjustment for other established risk factors, these associations were attenuated but remained significant in both age groups: the fully adjusted hazard ratios were 0.82 (0.77-0.87) and 0.88 (0.82-0.95), respectively.

CONCLUSIONS

These results provide evidence for an association between greater wellbeing and reduced risk of incident arthritis and, more generally, support the theory that psychosocial factors are implicated in the aetiology of this disease. Future research needs to delineate the mechanisms underlying the association between wellbeing and arthritis risk.

Well-Being and Chronic Disease Incidence: The English Longitudinal Study of Ageing

BACKGROUND

Previous research suggests that greater well-being may protect against onset of chronic disease. However, it is unclear whether this association is similar across different types of disease.

METHOD

We used Cox proportional hazards regression to examine the prospective relationship between well-being (measured using the CASP-19 quality of life questionnaire) and incidence of arthritis, cancer, stroke, diabetes, myocardial infarction, and chronic lung disease over 8 years. The sample consisted of 8182 participants 50 years or older from the English Longitudinal Study of Ageing.

RESULTS

After adjustments for established risk factors, a standard deviation increase in CASP-19 score was associated with a decrease in arthritis risk (hazard ratio [HR] = 0.89, 95% confidence interval [CI] = 0.83-0.96) and, in those younger than 65 years, a decrease in diabetes risk (HR = 0.82, 95% CI = 0.70-0.95) and chronic lung disease risk (HR = 0.80, 95% CI = 0.66-0.97). Higher CASP-19 scores were associated with reduced risk for stroke and myocardial infarction; however, these associations were no longer significant after adjustments for established risk factors. No association was observed for cancer incidence. An age interaction was observed for diabetes, myocardial infarction, and chronic lung disease, with a stronger association between CASP-19 score and disease incidence at younger ages.

CONCLUSIONS

The extent of association between well-being and incident disease risk is not consistent across different chronic diseases. Future studies should examine the cause of this variation.

A survey of overall life satisfaction and its association with breast diseases in Chinese women

To investigate the association between overall life satisfaction and healthy lifestyle, knowledge of breast cancer, physical examination, and detection rate of breast cancer and benign breast disease in Chinese women. In a multicentered breast disease screening program in China, we enrolled 33,057 women aged 45-65 years without prior diagnosis of breast cancer. After completing an epidemiological questionnaire, all participants were examined by clinical breast examination, breast ultrasound, and mammography independently. All breast cancer cases and a selected sample of benign breast diseases were confirmed pathologically. Univariate and multivariate odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the association between life satisfaction and lifestyle, knowledge of breast cancer, physical examination, and detection rate of breast diseases. Overall life satisfaction was positively associated with women's healthy lifestyle. Compared with less satisfied women, satisfied women were less likely to be smokers (OR = 0.54; 95% CI: 0.47-0.62), have more exercise (OR = 1.49; 95% CI: 1.26-1.75), eat less fried (OR = 0.60; 95% CI: 0.50-0.71), smoked (OR = 0.54, 95% CI: 0.47-0.63), pickled (OR = 0.66, 95% CI: 0.55-0.79), and grilled (OR = 0.63, 95% CI: 0.54-0.74) foods. Satisfied women were more likely to have knowledge of breast cancer (OR = 1.48, 95% CI: 1.29-1.70), and have regular physical examinations (OR = 1.11, 95% CI: 1.01-1.12). Compared to less satisfied women, we found significantly lower detection rate of benign breast diseases (OR = 0.90, 95% CI: 0.82-0.99), and lower but nonsignificant detection rate of breast cancer (OR = 0.66, 95% CI: 0.35-1.25) in satisfied women. Women with a higher overall life satisfaction are more likely to have healthy lifestyle, knowledge of breast cancer, and regular physical examination, thus resulting in a lower detection rate of breast diseases in screening.

Life satisfaction and risk of chronic diseases in the European prospective investigation into cancer and nutrition (EPIC)-Germany study

OBJECTIVE

The aim of the study was to examine the prospective association between life satisfaction and risk of type 2 diabetes mellitus, myocardial infarction, stroke, and cancer. Previous studies suggested that psychosocial factors may affect the development of chronic diseases but the impact of positive attitudes, in particular life satisfaction, is yet to be determined.

METHODS

The analysis included 50,358 participants of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Germany study in Potsdam and Heidelberg. Life satisfaction was assessed in a baseline interview and incident cases of chronic diseases were identified and verified during follow-up. Hazard ratios were calculated using Cox proportional hazards regression models that were systematically multivariable-adjusted for established risk factors and prevalent diseases.

RESULTS

During an average of 8 years of follow-up 2,293 cases of cancer, 1,840 cases of type 2 diabetes mellitus, 440 cases of stroke, and 562 cases of myocardial infarction were observed. Women who were unsatisfied with life at baseline showed in all models a significantly increased risk of cancer (HR: 1.45; 95% CI: 1.18-1.78) and stroke (HR: 1.69; 95% CI: 1.05-2.73) as well as an increased risk of type 2 diabetes mellitus by trend across categories (p-trend=0.04) compared to women very satisfied with life. In men, a relationship between life satisfaction and stroke was found but did not persist after consideration of lifestyle factors and prevalent diseases. No significant association was observed between life satisfaction and risk of myocardial infarction.

CONCLUSIONS

The results of this study suggest that reduced life satisfaction is related to the development of chronic diseases--particularly in women and partly mediated by established risk factors.

A case-control study on risk factors of breast cancer in China

INTRODUCTION

To screen the risk factors associated with breast cancer among Chinese women in order to evaluate the individual risk of developing breast cancer among women in China.

MATERIAL AND METHODS

A case-control study on 416 breast cancer patients and 1156 matched controls was conducted in 14 hospitals in 8 provinces of China in 2008. Controls were age- and region-matched to the cases. Clinicians conducted in-person interviews with the subjects to collect information on demographics and suspected risk factors for breast cancer that are known worldwide. Conditional logistic regression was used to derive odds ratios (OR) and 95% confidence intervals (CI) for the associations between risk factors and breast cancer.

RESULTS

Compared with matched controls, women with breast cancer were significantly more likely to have higher body mass index (BMI, OR = 4.07, 95% CI: 2.98-5.55), history of benign breast disease (BBD) biopsy (OR = 1.68, 95% CI: 1.19-2.38), older age of menarche (AOM) (OR = 1.41, 95% CI: 1.07-1.87), stress anticipation (SA), for grade 1-4, OR = 2.15, 95% CI: 1.26-3.66; for grade 5-9, OR = 3.48, 95% CI: 2.03-5.95) and menopause (OR = 2.22, 95% CI: 1.50-3.282) at the level of p < 0.05. Family history of breast cancer (FHBC) in first-degree relatives (OR = 1.66, 95% CI: 0.77-3.59) and use of oral contraceptives (OC) (OR = 1.59, 95% CI: 0.83-3.05) were associated with an increased risk of breast cancer at the level of p < 0.20.

CONCLUSIONS

Our results showed that BMI, history of BBD biopsy, older AOM, SA and menopause were associated with increased risk of breast cancer among Chinese women. The findings derived from the study provided some suggestions for population-based prevention and control of breast cancer in China.

Association between stress and breast cancer in women: a meta-analysis

The objective of the current meta-analysis was to verify the association between stressful life events and primary breast cancer incidence in women. A total of 618 studies from 1982-2007 were found in the PubMed, LILACS, and Cochrane Library databases. Methodological quality was evaluated according to the Downs & Black criteria. Eight studies were selected (six case-controls and two cohorts). The studies were grouped in three analyses, two of which based on the categories widowhood and divorce and the other based on self-rated intensity and frequency of stressful events. Relative risks were: widowhood 1.04 (95%CI: 0.75-1.44; p = 0.800); divorce 1.03 (95%: 0.72-1.48; p = 0.850); and intensity/frequency of stress 1.73 (95%CI: 0.98-3.05; p = 0.059). We conclude that stressful life events as a whole are not associated with risk of breast cancer in women. However, it is not possible to rule out high-intensity stress as a risk factor for breast cancer.

Cancer incidence in Israeli Jewish survivors of World War II

BACKGROUND

Israeli Jews of European origin have high incidence rates of all cancers, and many of them were exposed to severe famine and stress during World War II. We assessed cancer incidence in Israeli Jewish survivors of World War II.

METHODS

Cancer rates were compared in a cohort of 315 544 Israeli Jews who were born in Europe and immigrated to Israel before or during World War II (nonexposed group, n = 57 496) or after World War II and up to 1989 (the exposed group, ie, those potentially exposed to the Holocaust, n = 258 048). Because no individual data were available on actual Holocaust exposure, we based exposure on the immigration date for European-born Israeli Jews and decided against use of the term "Holocaust survivors," implying a known, direct individual Holocaust exposure. Cancer incidences were obtained from the Israel National Cancer Registry. Relative risk (RR) estimates and 95% confidence intervals (95% CIs) were calculated for all cancer sites and for specific cancer sites, stratified by sex and birth cohort, and adjusted for time period.

RESULTS

The nonexposed group contributed 908 436 person-years of follow-up, with 13 237 cancer diagnoses (crude rate per 100 000 person-years = 1457.1). The exposed group contributed 4 011 264 person-years of follow-up, with 56 060 cancer diagnoses (crude rate per 100 000 person-years = 1397.6). Exposure, compared with nonexposure, was associated with a statistically significantly increased risk for all-site cancer for all birth cohorts and for both sexes. The strongest associations between exposure and all-site cancer risk were observed in the youngest birth cohort of 1940-1945 (for men, RR = 3.50, 95% CI = 2.17 to 5.65; for women, RR = 2.33, 95% CI = 1.69 to 3.21). Excess risk was pronounced for breast cancer in the 1940-1945 birth cohort (RR = 2.44, 95% CI = 1.46 to 4.06) and for colorectal cancer in the 1935-1939 cohort (for men, RR = 1.75, 95% CI = 1.19 to 2.59; for women, RR = 1.93, 95% CI = 1.25 to 3.00).

CONCLUSIONS

Incidence of all cancers, particularly breast and colorectal cancer, was higher among Israeli Jews who were potentially exposed to the Holocaust than among those who were not.

Associations of ikigai as a positive psychological factor with all-cause mortality and cause-specific mortality among middle-aged and elderly Japanese people: findings from the Japan Collaborative Cohort Study

OBJECTIVE

To determine whether presence of ikigai as a positive psychological factor is associated with decreased risks for all-cause and cause-specific mortality among middle-aged and elderly Japanese men and women.

METHODS

From 1988 to 1990, a total of 30,155 men and 43,117 women aged 40 to 79 years completed a lifestyle questionnaire including a question about ikigai. Mortality follow-up was available for a mean of 12.5 years and was classified as having occurred in the first 5 years or the subsequent follow-up period. Associations between ikigai and all-cause and cause-specific mortality were assessed using a Cox's regression model. Multivariate hazard ratios (HRs) were adjusted for age, body mass index, drinking and smoking status, physical activity, sleep duration, education, occupation, marital status, perceived mental stress, and medical history.

RESULTS

During the follow-up period, 10,021 deaths were recorded. Men and women with ikigai had decreased risks of mortality from all causes in the long-term follow-up period; multivariate HRs (95% confidence intervals, CIs) were 0.85 (0.80-0.90) for men and 0.93 (0.86-1.00) for women. The risk of cardiovascular mortality was reduced in men with ikigai; the multivariate HR (95% CI) was 0.86 (0.76-0.97). Furthermore, men and women with ikigai had a decreased risk for mortality from external causes; multivariate HRs (95% CIs) were 0.74 (0.59-0.93) for men and 0.67 (0.51-0.88) for women.

CONCLUSION

The findings suggest that a positive psychological factor such as ikigai is associated with longevity among Japanese people.

Sense of life worth living (ikigai) and mortality in Japan: Ohsaki Study

OBJECTIVE

To investigate the association between the sense of "life worth living (ikigai)" and the cause-specific mortality risk. The psychological factors play important roles in morbidity and mortality risks. However, the association between the negative psychological factors and the risk of mortality is inconclusive.

METHODS

The Ohsaki Study, a prospective cohort study, was initiated on 43,391 Japanese adults. To assess if the subjects found a sense of ikigai, they were asked the question, "Do you have ikigai in your life?" We used Cox regression analysis to calculate the hazard ratio of the all-cause and cause-specific mortality according to the sense of ikigai categories.

RESULTS

Over 7 years' follow-up, 3048 of the subjects died. The risk of all-cause mortality was significantly higher among the subjects who did not find a sense of ikigai as compared with that in the subjects who found a sense of ikigai; the multivariate adjusted hazard ratio (95% confidence interval) was 1.5 (1.3-1.7). As for the cause-specific mortality, subjects who did not find a sense of ikigai were significantly associated with an increased risk of cardiovascular disease (1.6; 1.3-2.0) and external cause mortality (1.9; 1.1-3.3), but not of the cancer mortality (1.3; 1.0-1.6).

CONCLUSIONS

In this prospective cohort study, subjects who did not find a sense of ikigai were associated with an increased risk of all-cause mortality. The increase in mortality risk was attributable to cardiovascular disease and external causes, but not cancer.