Impact of musculoskeletal disorders on healthy life expectancy in Japan.

BACKGROUND: Musculoskeletal disorders are a key cause of morbidity in elderly people. How musculoskeletal disorders relate to healthy life expectancy remain elusive. Hence, we aimed to estimate gains in healthy life expectancy from the elimination of musculoskeletal diseases and injuries by using recent national health statistics data in Japan. METHODS: Mortality data were taken from Japanese national life tables and death certificates in 2016. Information on medical diagnoses, injuries, and activity were obtained from the 2016 Comprehensive Survey of Living Conditions. We examined five disorders: rheumatoid arthritis, arthrosis, low back pain, osteoporosis, and fracture. The prevalence of limitations in activities of daily living (ADL) in the population after eliminating the disorder was estimated as the proportion of outpatients without the disorder and ADL limitations, inpatients without the disorder in hospitals and clinics, and people without the disorder who reside in long-term elderly care facilities. RESULTS: There were small gains in life expectancy from elimination of all selected musculoskeletal disorders (0.0-0.1 years). Elimination of rheumatoid arthritis, osteoporosis, and fracture slightly increased the expected years without activity limitation (0.1-0.4) and slightly decreased years with activity limitation (0.1-0.4 years). Meanwhile, elimination of arthrosis, low back pain, and arthrosis and low back pain moderately increased expected years without activity limitation (0.3-1.5 years) and decreased years with activity limitation (0.3-1.5 years). In addition, elimination of rheumatoid arthritis, arthrosis, low back pain, osteoporosis, and fracture decreased expected years with ADL limitations (0.0-0.8 years) and non-ADL limitations (0.0-0.3 years). A combination of arthrosis and low back pain showed a moderate decrease in expected years with both ADL limitations (0.7-1.1 years) and non-ADL limitations (0.3-0.4). CONCLUSIONS: These findings provide clinical evidence that among the musculoskeletal disorders low back pain and arthrosis are the key factors for the elongation of healthy life expectancy.

Estimating nationwide cases of sexually transmitted diseases in 2015 from sentinel surveillance data in Japan.

BACKGROUND: The rates of newly diagnosed cases of sexually transmitted diseases, including genital chlamydial infection and gonorrhea, are important for prevention and control of these diseases. However, nationwide rates are not reported in Japan. METHODS: We used the number of cases of sexually transmitted diseases reported by nationwide sentinel surveillance in 2015, together with the number of all disease outpatients in September 2014 at all medical institutions, drawn from the Survey of Medical Institutions of Japan. The number of cases of sexually transmitted diseases in the total population was estimated using the ratio estimation method with the number of all disease outpatients as auxiliary information. This method is currently used for estimating influenza cases from sentinel surveillance data in Japan. RESULTS: The estimated number of newly diagnosed cases per 100,000 population in 2015 in Japan was 244 (95% confidence interval 211-277) for genital chlamydial infection, 87 (95% confidence interval 74-100) for genital herpes, 61 (95% confidence interval 29-93) for condyloma acuminatum, and 89 (95% confidence interval 64-113) for gonorrhea. CONCLUSION: We estimated the nationwide number of newly diagnosed cases of sexually transmitted diseases in Japan from sentinel surveillance data. This provides useful information for public health policy-making.

[The number of deaths by suicide after the Great East Japan Earthquake based on demographic statistics in the coastal and non-coastal areas of Iwate, Miyagi, and Fukushima prefectures].

Objective　The number of deaths by suicide after the Great East Japan Earthquake was surveyed based on demographic statistics. In particular, this study examined whether or not there were excessive deaths due to suicide (excluding people who were injured in the earthquake) after the Great East Japan Earthquake disaster. This examination surveyed municipalities in coastal and non-coastal areas of Iwate, Miyagi, and Fukushima prefectures (referred to below as the "three prefectures").Methods　The demographic statistics questionnaire survey information supplied by Article 33 of the Statistics Act (Ministry of Health, Labour and Welfare's published statistics Vol. 0925 No.4, September 25th, 2014) were used as the basic data with particular reference to the information on the deaths from January 1st, 2010 to March 31st, 2013. The information obtained included the date of death, the municipality where the address of the deceased was registered, the gender of the deceased, age at the time of death, and cause of death codes (International Classification of Disease Codes 10th revision: ICD-10). Additionally, information was gathered about the population based on the resident register from 2009 to 2013 and the 2010 National Census; the number of deaths by suicide was then totalled by period and area. The areas were classified as municipalities within three prefectures and those located elsewhere using the municipality where the address of the deceased was registered.Results　The SMR for suicides did not show a tendency to increase for coastal or non-coastal areas throughout the two-year period after the earthquake disaster (from March 2011 to February 2013).　The SMR for the three prefectures 0-1 years after the disaster compared with the year before the disaster was 0.92 and for 1-2 years after the disaster was 0.93. Both these values were significantly low. Looking at both the non-coastal and coastal areas from each of the three prefectures, the SMR for suicides for 0-1 and 1-2 years after the disaster compared with the year before the disaster ranged from 0.73 to 1.07. None were significantly high.Conclusion　The above results indicate that there was no increase in deaths by suicide in these three prefectures in the two years following the earthquake disaster.

[Changes in the average interval since last visit and the number of repeat outpatients in the Patient Survey of Japan].

Objectives　The Patient Survey provides basic information on disease and injury statistics of patients in Japan, and an estimation of the number of patients by disease and injury can be made using this survey. In this survey, the number of outpatients with repeat visits affects the survey results. The average interval since last visit (AILV) and a correction factor are used to estimate the number of repeat outpatients. Patients with AILV > 30 days are not included in the survey. However, in the last years, AILV exceeded 30 days in many cases, suggesting that the current 30-day threshold is no longer suitable. Thus, this study investigated the AILV in the current patient population and the effect of the increase in AILV on the number of repeat outpatients.Methods　Patients Survey data of 1996-2011 were used to estimate the effect of changing the AILV threshold on the number of repeat outpatients.Results　AILV increased for patients with most diseases and injuries. Using the current 30-day threshold, the overall outpatient coverage rate decreased from 91% in 1996 to 78% in 2011. A higher AILV threshold was necessary to maintain the overall outpatient coverage rate. For example, a threshold of 90 days increased the coverage rate in 2011 to 96%. However, raising the threshold markedly increased the number of repeat outpatients. For example, the overall number of repeat outpatients in 2011 increased from 43.01 million with the current 30-day threshold to 71.03 million using the 90-day threshold. The peak of the AILV of outpatients was observed on the next day after the first visit and the peak of the AILV of outpatients was observed every other week.Conclusion　AILV increased over time and changing the AILV threshold markedly increased the number of repeat outpatients and total patients, indicating that there is a need to raise the AILV threshold.

Effects of the Great East Japan Earthquake on Secondary Sex Ratio and Perinatal Outcomes.

BACKGROUND: The effect of natural disasters on secondary sex ratio (SSR) and perinatal outcomes has been suggested. This study aimed to examine effects of the Great East Japan Earthquake on perinatal outcomes using vital statistics of Japan. METHODS: Birth registration data from vital statistics of Japan between March 2010 and March 2012 were used. Pregnant women who experienced the earthquake were categorized according to their gestational period as of March 11, 2011, as follows: gestational weeks 4-11, 12-19, 20-27, and 28-36 (2011 group). Similarly, pregnant women who did not experience the earthquake were categorized according to their gestational period as of March 11, 2010 and used as controls (2010 group). We also categorized prefectures as "extremely affected", "moderately affected", and "slightly or unaffected" regions. SSR, birth weight, and gestational period were compared between both groups. RESULTS: The number of singleton births was 688,479 in the 2010 group and 679,131 in the 2011 group. In the extremely affected region, the SSR among women at 4-11 weeks of gestation was significantly lower in the 2011 group compared with the 2010 group (49.8% vs 52.1%, P = 0.009). In the extremely affected region, children born to women who experienced the earthquake at 28-36 weeks of gestation had significantly lower birth weights. CONCLUSIONS: The SSR declined among women who experienced the earthquake during early pregnancy, particularly in the extremely affected region. However, no apparent negative effect of the earthquake on perinatal outcomes was observed, although birth weight of infants who were born to women who experienced the earthquake at 28-36 weeks of gestation were lower.

Number of sentinel medical institutions needed for estimating prefectural incidence in influenza surveillance in Japan.

BACKGROUND: The sentinel surveillance system in Japan provides estimates of nationwide influenza incidence. Although prefectural influenza incidences can be estimated using data from the current surveillance system, such estimates may be imprecise. METHODS: We calculated the numbers of sentinel medical institutions (SMIs) needed in the surveillance system to estimate influenza incidences in prefectures, under the assumption that the standard error rates in 75% of influenza epidemic cases are less than 10%. Epidemic cases observed in 47 prefectures during the 2007/2008, 2008/2009, and 2009/2010 seasons, respectively, were used. RESULTS: The present total number of SMIs was 6669. With respect to current standards, the increases required in prefectures ranged from 0 to 59, and the total increase required in the number of SMIs was 1668. CONCLUSIONS: We used sentinel surveillance data for Japan to calculate the number of SMIs required to estimate influenza incidence in each prefecture.

Low intake of vegetables and fruits and risk of colorectal cancer: the Japan Collaborative Cohort Study.

BACKGROUND: The evidence for an association between low intake of vegetables and fruits and increased colorectal cancer risk is inconclusive. Evaluating the colorectal cancer risk associated with continued low intake is important. METHODS: We used data of 45 516 and 14 549 subjects aged 40-79 years obtained in the baseline and interim surveys, respectively, from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study). The intake frequency of vegetables and fruits as assessed by a self-administered questionnaire was classified into tertiles of low, middle, and high groups, and the low group was subdivided into 2 equal groups (lower low and higher low groups). Colorectal cancer incidence determined from follow-up was used. Cox's proportional hazard model was employed to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for covariates. RESULTS: During 598 605 person-years of subject follow-up after baseline, we identified 806 colorectal cancer cases. HRs for the lower low versus the middle and high intake frequencies of vegetables and fruits at baseline were 0.95 (95% CI 0.77-1.16) and 1.08 (95% CI 0.90-1.29), respectively. During 125 980 person-years of subject follow-up after the interim survey, 197 colorectal cancer cases were identified. HRs for the low versus middle and high intake frequencies of vegetables and fruits in both baseline and interim surveys were 0.91 (95% CI 0.61-1.37) and 0.87 (95% CI 0.59-1.27), respectively. CONCLUSIONS: Our results suggest that low intake and continued low intake of vegetables and fruits are not strongly associated with colorectal cancer risk.

Coffee consumption and risk of colorectal cancer: the Japan Collaborative Cohort Study.

BACKGROUND: Epidemiologic studies have reported coffee consumption to be associated with various health conditions. The purpose of this study was to examine the relationship of coffee consumption with colorectal cancer incidence in a large-scale prospective cohort study in Japan. METHODS: We used data from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study). Here, we analyzed a total of 58 221 persons (23 607 men, 34 614 women) followed from 1988 to the end of 2009. During 738 669 person-years of follow-up for the analysis of colorectal cancer risk with coffee consumption at baseline, we identified 687 cases of colon cancer (355 males and 332 females) and 314 cases of rectal cancer (202 males and 112 females). We used the Cox proportional-hazard regression model to estimate hazard ratio (HR). RESULTS: Compared to those who consumed less than 1 cup of coffee per day, men who consumed 2-3 cups of coffee per day had an HR of 1.26 (95% confidence interval [CI] 0.93-1.70), and men who consumed more than 4 cups of coffee per day had an HR of 1.79 (95% CI 1.01-3.18). A statistically significant increase in the risk of colon cancer was associated with increasing coffee consumption among men (P for trend = 0.03). On the other hand, coffee consumption in women was not associated with incident risk of colon cancer. Coffee consumption was also not associated with rectal cancer incidence in men or women. CONCLUSIONS: This large-scale population-based cohort study showed that coffee consumption increases the risk of colon cancer among Japanese men.

[Prediction of future cost savings in long-term care and medical care if Japan achieves the health expectancy target of Health Japan 21 (second term)].

OBJECTIVES: An earlier study using the data from the Japanese Long-term Care Insurance (LTCI) system reported a scenario for achieving the target of Health Japan 21 (the second term): future gains in health expectancy from 2011 to 2020 must be larger than gains in expectancy. According to this scenario (the Healthy Life Expectancy Extension Scenario), the proportion of disability (cases≥Care Level 2 in LTCI disability certification) will gradually decrease by 1% per year from 2011. The purpose of this study was to estimate the cost savings in long-term care and medical care if the Healthy Life Expectancy Extension Scenario is achieved. METHODS: We used data from Japanese national statistics and a survey conducted in Osaki city, Miyagi. The natural course of disability cases (≥Care Level 2) was estimated under the assumption that the future population composition would be equal to the population projections for Japan and the future proportion of disabilities for each age grade would be equal to that of 2010. Then, the decrease in the number of disabilities based on the Healthy Life Expectancy Extension Scenario was calculated. Finally, the cost savings in long-term care and medical care associated with the assumed decrease in the number of disability cases was calculated. RESULTS: When the disability cases (≥Care Level 2) were shifted to "no disability certification (not requiring care)," a total estimated cost reduction of 5,291 billion yen was achieved from 2011 to 2020. Furthermore, a total estimated reduction of 2,491 billion yen was achieved for the same period when all disability shifts to "Care Level 1" were accounted for. CONCLUSION: As a rough calculation, if the Health Japan 21 (second term) target is achieved, approximately 2,500-5,300 billion yen will be saved in the cost of long-term care and medical care.

[Future prediction of health expectancy considering the target of Health Japan 21 (the second term)].

OBJECTIVES: We attempted to predict health expectancy in Japan for the period between 2011 and 2020, considering the target of Health Japan 21 (the second term) that future gains in health expectancy be larger than in life expectancy. METHODS: We used data from Japanese national statistics. Health expectancy between 2011 and 2020 was predicted using the Sullivan method under the assumption that future mortality was equal to the estimate in Population Projections for Japan (January 2012), and under three scenarios of future prevalence of bad health status. RESULTS: The numbers of expected years without activity limitation at birth for males and females in 2020 were predicted as 71.2 and 74.3, respectively, under the scenario that prevalence of activity limitation was constant since 2010; 71.4 and 74.5 under the scenario that the prevalence followed the recent trend; and 71.7 and 74.9 under the scenario that the prevalence decreased with such a rate that future gains in health expectancy were equal to in life expectancy. The rate of decrease in the prevalence in 2010-2020 in the last scenario was estimated to be 0.95 in males and 0.96 in females. The numbers of expected years with subjective well-being at birth in 2020 predicted under above three scenarios were between 69.5 and 71.2 in males and between 72.9 and 74.6 in females. The rate of decrease in the last scenario was estimated to be 0.96 in males and 0.97 in females. The numbers of expected years without care needs at age 65 in 2020 predicted under above three scenarios were between 18.0-18.2 in males and between 21.2-21.5 in females. The rate of decrease in the last scenario was estimated to be 0.90 in males and 0.91 in females. CONCLUSION: The health expectancy in 2011-2020 was predicted under some scenarios of future prevalence of bad health status. The rate of decrease in the future prevalence of bad health status was estimated with a view to the accomplishment of the target of Health Japan 21 (the second term).

Intention to work among outpatients with malignant neoplasms, ischemic heart disease, and cerebrovascular disease.

Objectives: Employment support for working age people with disease is important. We investigated the intention to work among outpatients with malignant neoplasms, ischemic heart disease, and cerebrovascular disease. Methods: We used anonymous data from the 2007, 2010, and 2013 Comprehensive Survey of Living Conditions in Japan, a self-administered nationwide questionnaire survey. Data for 154,445 participants (76,059 men and 78,386 women) aged 20-64 years were analyzed using logistic regression models adjusted for covariates. Results: The number of outpatients with malignant neoplasms, ischemic heart disease, and cerebrovascular disease was 851, 1,037, and 716, respectively. The adjusted odds ratio for not working in people with the intention to work was significantly higher among outpatients with the three diseases than among non-outpatients, for both men and women. The adjusted odds ratio for intention to seek permanent work in unemployed people with the intention to work was lower among outpatients with cerebrovascular disease than among non-outpatients for men (p=0.093), and was significantly higher among outpatients with malignant neoplasms than among non-outpatients for women (p=0.007). Conclusions: This study identified a high proportion of unemployed people with the intention to work among outpatients with these three diseases, and suggests that there are disease-associated differences in employment type sought.

Gains in disability-free life expectancy from elimination of diseases and injuries in Japan.

BACKGROUND: Although disability-free life expectancy has been investigated in Japan, gains from elimination of diseases and injuries have not been examined. METHODS: We used data from the 2007 Japanese national health statistics to calculate the number of years with and without activity limitation that could be expected from eliminating 6 selected diseases and injuries. RESULTS: At birth, the number of expected years of life without and with activity limitation was 70.8 and 8.4, respectively, in males and 74.2 and 11.8 in females. More than 1.0 expected years without activity limitation were gained from eliminating malignant neoplasms and cerebrovascular diseases; smaller gains were observed after eliminating other diseases and injuries. Elimination of cerebrovascular diseases, dementia, and fracture decreased expected years with activities of daily living (ADL) limitation, and elimination of shoulder lesions/low back pain decreased expected years with non-ADL limitation. CONCLUSIONS: Elimination of diseases and injuries increased expected years with and without activity limitation among Japanese, which suggests that improved prevention of those diseases and injuries-including cerebrovascular diseases and dementia-would result in longer disability-free life expectancy and fewer years of severe disability.

Trends in life expectancy with care needs based on long-term care insurance data in Japan.

BACKGROUND: Using a previously developed method for calculating expected years of life with care needs based on data from the Japanese long-term care insurance system, we examined recent trends in expected years of life with care needs by age group and prefecture. METHODS: Information on care needs was available from the long-term care insurance system of Japan. Expected years of life with care needs by age group and prefecture in 2005-2009 were calculated. RESULTS: Expected years of life with care needs at age 65 increased from 1.43 years in 2005 to 1.62 years in 2009 for men, and from 2.99 to 3.44 years for women. As a proportion of total life expectancy, these values show an increase from 7.9% to 8.6% in men and from 12.9% to 14.4% in women. Expected years with care needs did not increase in the age groups of 65 to 69 and 70 to 74 years but markedly increased in the age group of 85 years or older. Expected years with care needs increased in every prefecture during the period studied. The difference in 2005 between the 25th and 75th percentiles in prefectural distributions was 0.16 years for men and 0.35 years for women. The difference remained nearly constant between 2005 and 2009. CONCLUSIONS: Expected number of years of life with care needs increased among Japanese from 2005 to 2009, and there was a wide range in distribution among prefectures. Further studies on coverage of care needs under the long-term insurance program are necessary.

Association between serum carotenoids and premature mortality in a population-based case-control study.

Carotenoids are abundant pigments mainly contained in vegetables and fruits, and show antioxidant properties by quenching free radicals in human body. Few studies have investigated associations between serum carotenoid levels and premature mortality. The objective of this study was to investigate the association between serum carotenoid level and premature mortality in a Japanese population. This study included 446 Japanese adults (174 men, aged of 40-64) recruited as participants in the Japan Collaborative Cohort (JACC) Study. Serum carotenoid level was measured by high-performance liquid chromatography. Premature mortality was defined as death before 65 years old during the follow-up period. Premature mortality was ascertained in 60 men (34.5%) and 65 women (23.9%). In men, compared to the 1st tertile of serum ß-cryptoxanthin and provitamin A, those who were in the 3rd tertile had lower risks of premature all-cause mortality (OR, 95% CI: 0.19, 0.07-0.47 for ß-cryptoxanthin, and 0.24, 0.09-0.61 for provitamin A). In women, compared to the 1st tertile of serum ß-cryptoxanthin, those who were in the 3rd tertile had higher risks of premature all-cause mortality (OR, 95% CI: 1.94, 1.00-4.03). These significant associations were observed in analyses for premature cancer mortality. We found significant associations between higher levels of serum ß-cryptoxanthin and provitamin A and lower risks of premature mortality among Japanese men, while a different directional association was found in women. Although these findings suggest roles of serum carotenoids on premature mortality, further studies are needed to validate this association in other populations.

Effect of coffee consumption on all-cause and total cancer mortality: findings from the JACC study.

Coffee consumption is known to be related to various health conditions. Recently, its antioxidant effects have been suggested to be associated with all-cause or cancer mortality by various cohort studies. However, there has been only one small Asian cohort study that has assessed this association. Thus, we tried to assess the association of coffee with all-cause and total cancer mortality by conducting a large-scale cohort study in Japan. A total of 97,753 Japanese men and women aged 40-79 years were followed for 16 years. Hazard ratios and 95% confidence intervals of all-cause and total cancer mortality in relation to coffee consumption were calculated from proportional-hazards regression models. A total of 19,532 deaths occurred during the follow-up period; 34.8% of these deaths were caused by cancer. The all-cause mortality risk decreased with increasing coffee consumption in both men and women, with a risk elevation at the highest coffee consumption level (≥4 cups/day) compared with the 2nd highest consumption level in women, although the number of subjects evaluated at this level was small. No association was found between coffee consumption and total cancer mortality among men, whereas a weak inverse association was found among women. The present cohort study among the Japanese population suggested that there are beneficial effects of coffee on all-cause mortality among both men and women. Furthermore, the results showed that coffee consumption might not be associated with an increased risk of total cancer mortality.

Circulating miR-21, miR-29a, and miR-126 are associated with premature death risk due to cancer and cardiovascular disease: the JACC Study.

Primary prevention of premature death is a public health concern worldwide. Circulating microRNAs (miRNAs) have been described as potential diagnostic biomarkers for diseases as cancer and cardiovascular disease (CVD). This case-cohort study aimed to investigate the potential relationship between circulating miRNAs and the risk of premature death. A total of 39,242 subjects provided baseline serum samples in 1988-1990. Of these, 345 subjects who died of intrinsic disease (< 65 years old) and for which measurable samples were available were included in this study. We randomly selected a sub-cohort of 879 subjects. Circulatring miR-21, miR-29a, and miR-126 were determined using qRT-PCR. Conditional logistic regression models were used to analyse the data with respect to stratified miRNA levels. Multivariable logistic regression revealed that subjects with high circulating miR-21 and miR-29a individual levels had a significantly higher risk of total death, cancer death, and CVD death than those with medium miR-21 and miR-29a individual levels. Conversely, subjects with low circulating miR-126 levels had a significantly higher risk of total death than those with medium levels. This suggests that circulating miRNAs are associated with the risk of premature death from cancer and CVD, identifying them as potential biomarkers for early detection of high-risk individuals.

Change in activities of daily living, functional capacity, and life satisfaction in Japanese patients with subacute myelo-optico-neuropathy.

BACKGROUND: There have been few reports on longitudinal change in activities of daily living (ADL), functional capacity, and life satisfaction in patients with subacute myelo-optico-neuropathy (SMON). METHODS: A total of 1309 SMON patients 40 to 79 years of age underwent a medical examination conducted by the SMON Research Committee during the period from 1993 through 1995 (baseline) in Japan; 666 (51%) were followed-up after 12 years and were thus eligible for analysis. We calculated scores for ADL, functional capacity, and life satisfaction at baseline, and at 3, 6, 9, and 12 years after baseline, using data from medical examinations conducted in 1993 through 2007. The Barthel Index, the Tokyo Metropolitan Institute of Gerontology Index of Competence, and the patient's response to the question "Are you satisfied with life?" were used to assess ADL, functional capacity, and life satisfaction, respectively. RESULTS: As compared with baseline, the mean scores for ADL, functional capacity, and life satisfaction were all significantly lower after 12 years in men and women, with the exception of life satisfaction in women. The change in scores for functional capacity from baseline to year 12 was significantly associated with change in life satisfaction; however, the changes in ADL and age at baseline were not. CONCLUSIONS: We observed decreases in ADL, functional capacity, and life satisfaction among SMON patients. Our results suggest that a decrease in life satisfaction can be prevented by maintaining or improving functional capacity.

Impact of smoking and other lifestyle factors on life expectancy among japanese: findings from the Japan Collaborative Cohort (JACC) Study.

BACKGROUND: A number of lifestyle factors, including smoking and drinking, are known to be independently associated with all-cause mortality. However, it might be more effective in motivating the public to adopt a healthier lifestyle if the combined effect of several lifestyle factors on all-cause mortality could be demonstrated in a straightforward manner. METHODS: We examined the combined effects of 6 healthy lifestyle behaviors on all-cause mortality by estimating life expectancies at 40 and 60 years of age among 62 106 participants in a prospective cohort study with a 14.5-year follow-up. The healthy behaviors selected were current nonsmoking, not heavily drinking, walking 1 hour or more per day, sleeping 6.5 to 7.4 hours per day, eating green leafy vegetables almost daily, and having a BMI between 18.5 to 24.9. RESULTS: At age 40, we found a 10.3-year increase in life expectancy for men and a 8.3-year increase for women who had all 6 healthy behaviors, as compared with those who had only 0 to 2 healthy behaviors. Increases of 9.6 and 8.2 years were observed for men and women, respectively, at age 60 with all 6 healthy behaviors. When comparing currently nonsmoking individuals with 0 to 1 healthy behaviors, the life expectancy of smokers was shorter in both men and women, even if they maintained all 5 other healthy behaviors. CONCLUSIONS: Among individuals aged 40 and 60 years, maintaining all 6 healthy lifestyle factors was associated with longer life expectancy. Smokers should be encouraged to quit smoking first and then to maintain or adopt the other 5 lifestyle factors.

Trends in disability-free life expectancy in Japan, 1995-2004.

BACKGROUND: In Japan, life expectancy at birth is currently the highest in the world. However, recent trends in disability-free life expectancy in Japan have not been examined. METHODS: We used data from Japanese national surveys for the period 1995-2004. These surveys included information on activity status measured by common self-reported instruments. The numbers of expected years with and without activity limitation were estimated by using the Sullivan method. RESULTS: The numbers of expected years of life without activity limitation, at birth, in 1995 and 2004 were 68.5 and 69.7, respectively, in males and 72.1 and 73.0 in females. As a proportion of total life expectancy, at birth, these values represent a decrease from 89.7% to 88.6% in males and from 87.1% to 85.3% in females. The proportion of expected years with a limitation of some activities except activities of daily living (ADL) increased in males and females. The proportion of those with an ADL limitation increased in females, but not in males. CONCLUSIONS: The trends in expected years with and without activity limitation suggest that the duration of life with a light or moderate disability increased in Japanese males and females during the period 1995-2004.