Projecting the probability of survival free from cancer and cardiovascular incidence through lifestyle modification in Japan

Regional Variation in National Healthcare Expenditure and Health System Performance in Central Cities and Suburbs in Japan

The increasing national healthcare expenditure (NHE) with the aging rate is a significant social problem in Japan, and efficient distribution and use of NHE is an urgent issue. It is assumed that comparisons in subregions would be important to explore the regional variation in NHE and health system performance in targeted municipalities of the metropolitan area of Tokyo (central cities) and the neighboring municipalities of Chiba Prefecture (suburbs). This study aimed to clarify the differences of the socioeconomic factors affecting NHE and the health system performances between subregions. A multiple regression analysis was performed to extract the factors affecting the total medical expenses of NHE (Total), comprising the medical expenses of inpatients (MEI), medical expenses of outpatients (MEO), and consultation rates of inpatients (CRI) and outpatients (CRO). Using the stepwise method, dependent variables were selected from three categories: health service, socioeconomic, and lifestyle. Then, health system performance analysis was performed, and the differences between regions were clarified using the Mann–Whitney U test. The test was applied to 18 indicators, classified into five dimensions referred to in the OECD indicators: health status, risk factors for health, access to care, quality of care, and health system capacity and resources. In the central cities, the number of persons per household was the primary factor affecting Total, MEI, MEO, and CRO, and the number of persons per household and the percentage of the entirely unemployed persons primarily affected CRI. In the suburbs, the ratio of the population aged 65–74 and the number of hospital beds were significantly positively related to Total, MEI, and CRI, but the number of workers employed in primary industries was negatively related to Total and MEI. The ratio of the population aged 65–74 was significantly positively related to MEO and CRO. Regarding health system performance, while risk factors for health was high in the central cities, the others, including access to care, quality of care, and health system capacity and resources, were superior in the suburbs, suggesting that the health system might be well developed to compensate for the risks. In the suburbs, while risk factors for health were lower than those in the central cities, access to care, quality of care, and health system capacity and resources were also lower, suggesting that the healthcare system might be poorer. These results indicate a need to prioritize mitigating healthcare disparities in the central cities and promoting the health of the elderly in the suburbs by expanding the suburbs’ healthcare systems and resources. This study clarified that the determinants of NHE and health system performance are drastically varied among subregional levels and suggested the importance of precise regional moderation of the healthcare system.

Risk of stroke in cancer survivors using a propensity score-matched cohort analysis

Little is known about the risk of cerebrovascular disease in cancer survivors. We aimed to assess the association between incident cancer and the subsequent risk of stroke using a large-scale, population-based prospective study. 74,530 Japanese aged between 40 and 69 years at baseline study were matched by the status of cancer diagnosis during follow-up using propensity score nearest-neighbor matching with allowance for replacement. A total of 2242 strokes were reported during 557,885 person-years of follow-up. Associations between incident cancer and the subsequent risk of all strokes, cerebral infarction, and intracerebral hemorrhage were assessed using a Cox proportional hazards model stratified on the propensity score-matched pairs. No significant association was observed between the status of cancer diagnosis of all types, gastric, colorectal and lung cancer, and subsequent occurrence of all strokes, cerebral infarction, and intracerebral hemorrhage. However, analysis by discrete time periods suggested an elevated risk in cancer patients for one to three months after a cancer diagnosis in all stroke (HR, 2.24; 95% CI, 1.06, 4.74) and cerebral infarction (HR, 2.62; 95% CI, 1.05, 6.53). This prospective cohort study found no association between the status of cancer diagnosis and the subsequent occurrence of all strokes and its subtypes during the entire follow-up period but suggested an increase in stroke risk during the active phase of malignancy.

The Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT): Study Design and Participants

Background

Lifestyle and life-environment factors have undergone drastic changes in Japan over the last few decades. Further, many molecular epidemiologic studies have reported that genetic, epigenetic, and other biomarker information may be useful in predicting individual disease risk.

Methods

The Japan Public Health Center-based Prospective Study for the Next Generation (JPHC-NEXT) was launched in 2011 to identify risk factors for lifestyle-related disease, elucidate factors that extend healthy life expectancy, and contribute toward personalized healthcare based on our more than 20 years’ experience with the JPHC Study. From 2011 through 2016, a baseline survey was conducted at 16 municipalities in seven prefectures across the country. A self-administered questionnaire was distributed to all registered residents aged 40–74, which mainly asked about lifestyle factors, such as socio-demographic situation, personal medical history, smoking, alcohol and dietary habits. We obtained informed consent from each participant to participate in this long follow-up study of at least 20 years, including consent to the potential use of their residence registry, medical records, medical fee receipts, care insurance etc., and to the provision of biospecimens (blood and urine), including genomic analysis.

Results

As of December 31, 2016, we have established a population-based cohort of 115,385 persons (Response rate 44.1%), among whom 55,278 (47.9% of participants) have provided blood and urine samples. The participation rate was slightly higher among females and in the older age group.

Conclusion

We have established a large-scale population-based cohort for next-generation epidemiological study in Japan.

Impact of drinking and smoking habits on cerebrovascular disease risk among male employees

OBJECTIVE

We aimed to analyze the impact of drinking and smoking behavior on the risk of developing cerebrovascular diseases among male employees aged 20-46 years. Twenty years of follow-up data of male employees enrolled in the DENSO Health Insurance Program were used for analyses.

SUBJECTS AND METHODS

Of 29,048 male employees aged 20-46 years who were enrolled in the insurance program in 1994, 25,084 (86.4%) employees underwent annual health check-ups until 2003 without missing an appointment. Of these 25,084 employees, the data of 11,784 (40.6%) employees who self-reported drinking and smoking habits were used for analyses. The hazard ratio and 95% confidence intervals (CIs) for developing cerebrovascular disease in 2004-2013 were calculated in four risk groups categorized as per drinking and smoking behavior in the young group who were in their 20s and the middle-aged group who were in their 30s-40s in 1994. Based on their drinking behavior, participants were categorized into two groups: "not drinking or drinking sometimes" and "drinking every day." Based on their smoking behavior, participants were also categorized into two groups: "not smoking for 10 years" and "smoking for 10 years."

RESULTS

A Cox's proportional hazard model revealed that after controlling for body mass index, systolic blood pressure, triglycerides, total cholesterol, fasting plasma glucose, and age, the hazard ratios for "smoking and drinking every day" were 3.82 (95% CI: 1.40-10.41) in the young group and 2.31 (95% CI: 1.27-4.17) in the middle-aged group.

DISCUSSION

Male employees who had been drinking and smoking for 10 years had a higher risk of developing cerebrovascular diseases. To prevent cerebrovascular diseases among male employees, it may be effective to offer behavior change interventions for both drinking and smoking habits, regardless of the age group.

Impact of five modifiable lifestyle habits on the probability of cancer occurrence in a Japanese population-based cohort: results from the JPHC study

OBJECTIVE

The present work aims to provide 10-year estimates of the probability of cancer occurrence in the Japanese population based on age, sex, and the pattern of adherence to five healthy lifestyle habits.

METHODS

The study population consisted of 74,935 participants in the Japan Public Health Center-Based Prospective Study (aged 45 to 74 years) who answered a 5-year follow-up questionnaire about various lifestyle habits between 1995 and 1999. The relationship between five previously identified healthy lifestyle habits (never smoking, moderate or no alcohol consumption, adequate physical activity, moderate salt intake, and appropriate body mass index) and cancer occurrence was assessed using a sex-specific parametric survival model.

RESULTS

Compared to individuals not adhering to any of the five habits, never-smoking men had a nearly 30% reduction in the 10-year probability of cancer occurrence (e.g., 20.5% vs. 28.7% at age 70), and never-smoking women had a 16% reduction (e.g., 10.5% vs. 12.5% at age 70). Adherence to all five habits was estimated to reduce the 10-year probability of cancer occurrence by 1/2 in men and 1/3 in women.

CONCLUSION

By quantifying the impact of lifestyle habits on the probability of cancer occurrence, this study emphasizes the importance of lifestyle improvement.

Combined impact of five lifestyle factors and subsequent risk of cancer: the Japan Public Health Center Study

OBJECTIVE

To evaluate whether 5 combined healthy lifestyle factors (not smoking, moderate drinking, eating minimum salt-preserved foods, being physically active, and having appropriate body mass index) are associated with reduced risk of cancer.

METHODS

Participants were enrolled in the Japan Public Health Center Study and responded to the 5-year follow-up questionnaire covering lifestyle factors in 1995-1999 at ages 45-74 years. During follow up through December 31, 2006, 3451 and 2125 cases of cancer were newly identified in men and women, respectively. For men and women, a factor-dependent risk reduction was observed for healthy lifestyles and cancer development. Compared to 0-1 healthy lifestyle factors, the adjusted RRs and 95% CIs for adherence to 2, 3, 4, and 5 healthy factors were 0.86 (0.78-0.95), 0.72 (0.65-0.80), 0.61 (0.54-0.69), and 0.57 (0.45-0.72), respectively, for men (P for trend<0.0001) and 0.86 (0.53-1.40), 0.73 (0.46-1.16), 0.68 (0.42-1.08), and 0.63 (0.39-1.01), respectively, for women (P for trend=0.0003). Risk was reduced 14% and 9% by each one healthy lifestyle for men and women, respectively. Risk reduction was more pronounced among elderly women.

CONCLUSION

These combined lifestyle factors have a considerable impact on preventing cancer.