The World Health Organization (WHO) has recommended that countries develop national cancer control programs in order to reduce the number of deaths due to preventable cancers. The national cancer control program should be comprehensive and systematic with evidence-based priority-setting and the efficient use of limited resources. In order to provide evidence-based information, cancer surveillance systems must be established with registration as a focus. Cancer registration monitors the incidence, mortality, survival, and prevalence of cancers. In Japan, however, cancer registration systems have not been either well developed or standardized until recently. In 2003, the Ministry of Health, Labour and Welfare of Japan launched the Third Term Comprehensive 10-Year Strategy Program for Cancer Control, which gave grants to several projects to enhance the dissemination and standardization of cancer registries. However, the establishment of a cancer registration system is merely the first step in the process to provide a comprehensive surveillance system that leads to a national cancer control program, as proposed by the WHO. To provide the best cancer care services equitably in Japan, cancer surveillance systems should be established without delay. J Epidemiol 2005; 15: 199-202.
BACKGROUND: Few studies have investigated the interaction between the Trp64Arg polymorphism of the β3-adrenergic receptor gene (ADRB3) and environmental factors. This study aimed to investigate whether energy intake affects the relationship between this polymorphism and obesity. METHODS: Healthy Japanese men (n=295; age 46.1±11.5 years (mean ±standard deviation); waist circumference 83.9±9.3 cm; body mass index (BMI) 23.3±3.3 kg/m2) recruited in a Japanese chemical industry firm were eligible for analysis. Daily energy intake, protein, fat, and carbohydrate (PFC) ratio and daily physical activity were assessed by self-reported questionnaires. Genotyping for the polymorphism was performed with written informed consent. RESULTS: When the subjects were classified into two groups according to presence of the polymorphism, the groups were not significantly different in waist circumference or BMI. Quartile classification of energy intake, however, demonstrated a significantly larger ratio of obese subjects to non-obese subjects in the group with the polymorphism in the highest 4th quartile alone. Multiple logistic regression analysis also revealed that the presence of the polymorphism increased the risk of obesity significantly in the 4th quartile alone (adjusted odds ratio=3.37, 95% confidence interval=1.12-10.2). CONCLUSION: Presence of the polymorphism alone does not significantly increase the risk of obesity. However, high energy intake interacts with the polymorphism and leads to a significant increase in risk of obesity. The Trp64Arg polymorphism of ADRB3 warrants consideration, along with other polymorphisms involved in the development of obesity, for tailor-made prevention of obesity. J Epidemiol 2005; 15: 203-210.
BACKGROUND: Several investigations have adopted self-reported intake frequency of fish as a surrogate for intake of long-chain n-3 fatty acids, for which protective effects against cancer have been suggested. Whether reported fish consumption reflects the fatty acid intake, however, has to be elucidated. METHODS: We examined the association between intake frequency of fish and serum long-chain n-3 fatty acids (weight percentage of total fatty acids) among 1,257 control subjects (631 men and 626 women), aged 40-79 years, in case-control studies nested in the Japan Collaborative Cohort Study. All the subjects were not fasting when blood was drawn. Serum fatty acids were determined by gas chromatography. RESULTS: In men, intake frequency of fresh fish and dried or salted fish was significantly but weakly correlated with serum levels of eicosapentaenoic (EPA), docosapentaenoic (n-3) (DPA), and docosahexaenoic (DHA) acids; the age-adjusted Spearman correlation coefficients ranged from 0.11 to 0.18. In women, fresh fish consumption was somewhat associated with serum EPA (Spearman correlation coefficient = 0.12) as was dried or salted fish consumption with serum DPA (0.11). A rising trend in geometric means of serum EPA, DPA, and DHA was found with an increasing intake frequency of fresh or dried/salted fish in both sexes. The geometric means adjusted for age and participating institution in the highest intake category were higher than those in the lowest by 7% to 40%. CONCLUSIONS: A population with high self-reported frequency of fish intake, as a group, may have higher bioavailability of long-chain n-3 fatty acids than one with low frequency. J Epidemiol 2005; 15: 211-218.
BACKGROUND: Disability-free life expectancy (DFLE) data for 47 prefectures in Japan were reported in 1999; however, few studies have identified the factors associated with the length of the DFLE. The objective of this study was to elucidate the primary factors that explain differences in DFLEs in Japan. METHODS: In our ecological study, 47 prefectures in Japan were used as units of analysis. The DFLEs for men and women at 65 years of age (DFLE65), calculated by Hashimoto et al using Sullivan's method, were set as dependent variables. From various national surveys, 181 factors associated with demographics, socioeconomic status, health status and health behaviors, medical environment, social relationships, climate, and other areas were gathered as independent variables. Pearson's or Spearman's correlation coefficients were calculated to screen independent variables potentially associated with the DFLE65s. Then, multivariate linear regression analyses were conducted for the selected 24 independent variables after adjusting for the proportion of older people (65 years or more) and population density. RESULTS: Multivariate linear regression analyses revealed that the large number of public health nurses per 100,000 population, a good self-reported health status, and a high proportion of older workers were significantly associated with long DFLE65s for both genders. CONCLUSIONS: These three factors could potentially explain the differences in DFLE of the older population in Japan. J Epidemiol 2005; 15:219-227.
BACKGROUND: The job characteristics scale of job strain, which combines high job demands and low decision latitude based on Karasek's model, has been applied to studies on health care and cardiovascular disease. However, little is known about the long-term stability of this scale with exposure of workers to job. We investigated the 5-year intraindividual variation in job characteristics scores among healthy community workers. METHODS: Subjects of the study were 458 community dwelling persons forming part of the Jichi Medical School Cohort Study at Yamato (currently, Minami-Uonuma city), Niigata prefecture. The Japanese version of the World Health Organization Multinational Monitoring of Trends and Determinants in Cardiovascular Disease (WHO-MONICA) Psychosocial Study Questionnaire was implemented twice (from 1992 through 1995, and in 1999) to measure job demands and decision latitude levels. Intraclass correlation coefficients were computed to evaluate stability of scores of the questionnaire. RESULTS: Intraclass correlation coefficient of the decision latitude scores was 0.629 (95% confidence interval: 0.564 - 0.686) and that of the job demands scores was 0.551 (0.476 - 0.617). Subgroup analyses by age, sex, education level, years since first employment, number of co-workers, and job category and status at baseline revealed similar results. In contrast, subjects who experienced position changes within the same enterprise or changed jobs showed lower correlation coefficients of both decision latitude and job demands scores compared to those who experienced no change in job contents. CONCLUSION: The Japanese version of the WHO-MONICA Psychosocial Study Questionnaire showed statistically significant long-term stability and could be to some extent responsive to change in job strain levels. J Epidemiol 2005; 15:228-234.
BACKGROUND: This study evaluates the statistical and discriminatory powers of three statistical test methods (Begg's, Egger's, and Macaskill's) to detect publication bias in meta-analyses. METHODS: The data sources were 130 reviews from the Cochrane Database of Systematic Reviews 2002 issue, which considered a binary endpoint and contained 10 or more individual studies. Funnel plots with observers'agreements were selected as a reference standard. We evaluated a trade-off between sensitivity and specificity by varying cut-off p-values, power of statistical tests given fixed false positive rates, and area under the receiver operating characteristic curve. RESULTS: In 36 reviews, 733 original studies evaluated 2,874,006 subjects. The number of trials included in each ranged from 10 to 70 (median 14.5). Given that the false positive rate was 0.1, the sensitivity of Egger's method was 0.93, and was larger than that of Begg's method (0.86) and Macaskill's method (0.43). The sensitivities of three statistical tests increased as the cut-off p-values increased without a substantial decrement of specificities. The area under the ROC curve of Egger's method was 0.955 (95% confidence interval, 0.889-1.000) and was not different from that of Begg's method (area=0.913, p=0.2302), but it was larger than that of Macaskill's method (area=0.719, p=0.0116). CONCLUSION: Egger's linear regression method and Begg's method had stronger statistical and discriminatory powers than Macaskill's method for detecting publication bias given the same type I error level. The power of these methods could be improved by increasing the cut-off p-value without a substantial increment of false positive rate. J Epidemiol 2005; 15: 235-243.
BACKGROUND: Our prior study revealed that nearly half of the Japanese women between the ages of 35 and 49 years experience an unintended pregnancy, many of which are carried to term. The present study is intended to investigate the association of the intention to become pregnant with parenting difficulty after birth. METHODS: We distributed self-administered questionnaires to mothers of 317 randomly selected children aged 3 to 18 months who resided in Sukagawa City, Fukushima. The extent to which the unintended pregnancy is associated with the risk of negative attitude in parenting was examined by using multiple logistic regression analysis. RESULTS: The response rate was 69% and the proportion of births, the outcome of an unintended pregnancy, 22%. When the pregnancy was unintended, the mother may not deny her feelings toward child abuse (odds ratio [OR] = 5.2). She was unlikely to have discussion about child rearing with her husband (OR=3.1) or family (OR=3.3); or the husband rarely participate in child rearing (OR=1.9). CONCLUSION: To improve the child rearing environment, these findings provide preliminary evidence to underscore the importance of pregnancy planning and providing services to augment the parenting skills of couples who have an unintended pregnancy. A follow-up of pregnant women is currently underway to examine prospectively the effects on child rearing of one's intention to become pregnant. J Epidemiol 2005; 15: 244-246.