Journal of Epidemiology
Online ISSN : 1349-9092
Print ISSN : 0917-5040
ISSN-L : 0917-5040
Volume 27, Issue 4
Displaying 1-7 of 7 articles from this issue
Original Articles
  • Hui Li, Xuezheng Sun, Erline Miller, Qiong Wang, Ping Tao, Li Liu, Yin ...
    2017 Volume 27 Issue 4 Pages 143-151
    Published: 2017
    Released on J-STAGE: April 25, 2017
    Supplementary material

    Background: The effects of body mass index (BMI) and reproductive factors may vary among breast cancer molecular subtypes, evidence of which is lacking in East Asia.

    Methods: From 2002 to 2010, 1256 breast cancer patients and 1416 healthy women were recruited. Anthropometric and reproductive factors were collected from medical charts. Breast cancer subtype was defined by ER, PR, and HER2 status. Polytomous logistic regression was used to evaluate associations between risk factors and breast cancer subtypes, with subgroup analysis by menopausal status. A metaanalysis of relevant published studies in East Asia was also performed.

    Results: In our case-control study, late menarche was negatively associated with luminal tumor risk (Ptrend = 0.03). Higher BMI was associated with risk of both luminal and triple-negative tumors (Ptrend<0.001). Late age at first live birth was associated with a 1.41- to 2.08-fold increased risk of all subtypes, while late menopause increased risk by 2.62–5.56 times. Heterogeneity of these associations was not detected for different menopausal statuses. The meta-analysis revealed a positive dose-response relationship between BMI and risk of both luminal and ER-PR- subtypes (Ptrend<0.05). Early menarche and nulliparity increased luminal tumor risk by 1.39 and 1.26 times, respectively. Non-breastfeeding also increased the risk of all subtypes.

    Conclusions: For East Asian women, overweight, late menopause, and lack of breastfeeding appear to increase risk of both luminal and ER–PR– tumors. Early menarche and nulliparity mainly impacted luminal tumor risk. These associations were not impacted by menopausal status.

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  • Ribeka Takachi, Manami Inoue, Yumi Sugawara, Ichiro Tsuji, Shoichiro T ...
    2017 Volume 27 Issue 4 Pages 152-162
    Published: 2017
    Released on J-STAGE: April 25, 2017

    Background: A series of recent reports from large-scale cohort studies involving more than 100,000 subjects reported no or only very small inverse associations between fruit and vegetable intake and overall cancer incidence, despite having sufficient power to do so. To date, however, no such data have been reported for Asian populations.

    Objective: To provide some indication of the net impact of fruit and vegetable consumption on overall cancer prevention, we examined these associations in a pooled analysis of large-scale cohort studies in Japanese populations.

    Methods: We analyzed original data from four cohort studies that measured fruit and vegetable consumption using validated questionnaires at baseline. Hazard ratios (HRs) in the individual studies were calculated, with adjustment for a common set of variables, and combined using a random-effects model.

    Results: During 2,318,927 person-years of follow-up for a total of 191,519 subjects, 17,681 cases of overall cancers were identified. Consumption of fruit or vegetables was not associated with decreased risk of overall cancers: corresponding HRs for the highest versus lowest quartiles of intake for men and women were 1.03 (95% CI, 0.97–1.10; trend p = 1.00) and 1.03 (95% CI, 0.95–1.11; trend p = 0.97), respectively, for fruit and 1.07 (95% CI, 1.01–1.14; trend p = 0.18) and 0.98 (95% CI, 0.91–1.06; trend p = 0.99), respectively, for vegetables, even in analyses stratified by smoking status and alcohol drinking.

    Conclusions: The results of this pooled analysis do not support inverse associations of fruit and vegetable consumption with overall cancers in the Japanese population.

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  • Judith Godin, Janice Keefe, Melissa K. Andrew
    2017 Volume 27 Issue 4 Pages 163-171
    Published: 2017
    Released on J-STAGE: April 25, 2017

    Background: Missing values are commonly encountered on the Mini Mental State Examination (MMSE), particularly when administered to frail older people. This presents challenges for MMSE scoring in research settings. We sought to describe missingness in MMSEs administered in long-term-care facilities (LTCF) and to compare and contrast approaches to dealing with missing items.

    Methods: As part of the Care and Construction project in Nova Scotia, Canada, LTCF residents completed an MMSE. Different methods of dealingwith missing values (e.g., use of raw scores, raw scores/number of items attempted, scale-level multiple imputation [MI], and blended approaches) are compared to item-level MI.

    Results: The MMSE was administered to 320 residents living in 23 LTCF. The sample was predominately female (73%), and 38% of participants were aged >85 years. At least one item was missing from 122 (38.2%) of the MMSEs. Data were not Missing Completely at Random (MCAR), χ2 (1110) = 1,351, p < 0.001. Using raw scores for those missing <6 items in combination with scale-level MI resulted in the regression coefficients and standard errors closest to item-level MI.

    Conclusions: Patterns of missing items often suggest systematic problems, such as trouble with manual dexterity, literacy, or visual impairment. While these observations may be relatively easy to take into account in clinical settings, non-random missingness presents challenges for research and must be considered in statistical analyses. We present suggestions for dealing with missing MMSE data based on the extent of missingness and the goal of analyses.

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  • Mie Shiraishi, Megumi Haruna, Masayo Matsuzaki, Ryoko Murayama, Satosh ...
    2017 Volume 27 Issue 4 Pages 172-179
    Published: 2017
    Released on J-STAGE: April 25, 2017

    Background: Accurate and easy dietary assessment methods that can be used during pregnancy are required in both epidemiological studies and clinical settings. To verify the utility of dietary assessment questionnaires in pregnancy, we examined the validity and reliability of a self-administered diet history questionnaire (DHQ) and a brief-type self-administered diet history questionnaire (BDHQ) to measure energy, protein, sodium, and potassium intake among pregnant Japanese women.

    Methods: The research was conducted at a university hospital in Tokyo, Japan, between 2010 and 2011. The urinary urea nitrogen, sodium, and potassium levels were used as reference values in the validation study. For the reliability assessment, participants completed the questionnaires twice within a 4-week interval.

    Results: For the DHQ (n = 115), the correlation coefficients between survey-assessed energy-adjusted intake and urinary protein, sodium, and potassium levels were 0.359, 0.341, and 0.368, respectively; for the BDHQ (n = 112), corresponding values were 0.302, 0.314, and 0.401, respectively. The DHQ-measured unadjusted protein and potassium intake levels were significantly correlated with the corresponding urinary levels (rs = 0.307 and rs = 0.342, respectively). The intra-class correlation coefficients for energy, protein, sodium, and potassium between the time 1 and time 2 DHQ (n = 58) and between the time 1 and time 2 BDHQ (n = 54) ranged from 0.505 to 0.796.

    Conclusions: Both the DHQ and the BDHQ were valid and reliable questionnaires for assessing the energy-adjusted intake of protein, sodium, and potassium during pregnancy. In addition, given the observed validity of unadjusted protein and potassium intake measures, the DHQ can be a useful tool to estimate energy intake of pregnant Japanese women.

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  • Atsushi Takahashi, Tetsuya Ohira, Mitsuaki Hosoya, Seiji Yasumura, Mas ...
    2017 Volume 27 Issue 4 Pages 180-185
    Published: 2017
    Released on J-STAGE: April 25, 2017

    Background: The Great East Japan Earthquake and subsequent Fukushima Daiichi Nuclear Power Plant accident caused residents to switch from their normal lives to lives focused on evacuation. We evaluated liver function before and after this disaster to elucidate the effects of evacuation on liver function.

    Methods: This study was a longitudinal survey of 26,006 Japanese men and women living near the Fukushima Daiichi Nuclear Power Plant. This study was undertaken using data from annual health checkups conducted for persons aged 40–90 years between 2008 and 2010. Follow-up examinations were conducted from June 2011 to the end of March 2013, with a mean follow up of 1.6 years. Changes in liver function before and after the disaster were compared among evacuees and non-evacuees. We also assessed groups according to alcohol drinking status.

    Results: The prevalence of liver dysfunction significantly increased in all participants from 16.4% before to 19.2% after the disaster. The incidence of liver dysfunction was significantly higher in evacuees than in non-evacuees. Multivariate logistic regression analysis showed that evacuation was significantly associated with liver dysfunction among residents.

    Conclusions: This is the first study to show that evacuation due to the Fukushima Daiichi nuclear power plant disaster was associated with an increase in liver dysfunction.

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  • Takahiro Tabuchi, Naoki Kondo
    2017 Volume 27 Issue 4 Pages 186-192
    Published: 2017
    Released on J-STAGE: April 25, 2017
    Supplementary material

    Background: Few studies have investigated differences in age- and gender-specific educational gradients in tobacco smoking among the whole range of adult age groups. We examined educational inequality in smoking among Japanese adults aged 25–94 years.

    Methods: Using a large nationally representative sample (167,925 men and 186,588 women) in 2010, prevalence of current smoking and heavy smoking among daily smokers and their inequalities attributable to educational attainment were analyzed according to sex and age groups.

    Results: Among men aged 25–34 years, junior high school graduates had the highest current smoking prevalence at 68.4% (95% confidence interval [CI], 66.0%–70.6%), and graduate school graduates had the lowest at 19.4% (95% CI, 17.2%–21.9%). High school graduates had the second highest current smoking prevalence (e.g., 55.9%; 95% CI, 54.9%–56.8% in men aged 25–34 years). Among men aged 75–94 years, the difference in current smoking across educational categories was small. A similar but steeper educational gradient in current smoking was observed among women. Among women aged 25–34 years, junior high school graduates had the highest current smoking prevalence at 49.3% (95% CI, 46.3%–52.3%), and graduate school graduates had the lowest at 4.8% (95% CI, 2.9%–7.4%). Compared with older age groups, such as 65–94 years, younger age groups, such as 25–54 years, had higher estimates of inequality indicators for educational inequality in both current and heavy smoking in both sexes.

    Conclusions: Educational inequalities in current and heavy smoking were apparent and large in the young population compared with older generations. The current study provides basic data on educational inequalities in smoking among Japanese adults.

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Study Profile
  • Junya Sado, Tetsuhisa Kitamura, Yuri Kitamura, Ling Zha, Rong Liu, Tom ...
    2017 Volume 27 Issue 4 Pages 193-199
    Published: 2017
    Released on J-STAGE: April 25, 2017

    Background: We reutilized the existing Three-Prefecture Cohort to evaluate the relationship between lifestyle factors and the incidence or mortality from non-communicable diseases.

    Methods: This study was a prospective population-based observation conducted from the 1980s to 2000 in three prefectures (Miyagi, Aichi, and Osaka) in Japan. The study subjects were residents aged ≥40 years who received a questionnaire. The follow-up period was 15 years from the baseline survey in each study area. A self-administered questionnaire, which included items on participants' demographic factors and lifestyle characteristics, was administered. Vital status and date of death were collected from residence certificates by the local government, and cause of death was identified using vital statistics. Cancer incidence and the date of diagnosis were collected from local cancer registry data.

    Results: A total of 46,421 men and 54,189 women were eligible for our analysis. The person-years of follow-up for cancer incidence were 464,664 and 567,271 for men and women, respectively, and those for death were 527,940 and 648,601 for men and women, respectively. There were 8479 cancer incidences (5106 men and 3373 women) and 20,240 total deaths (11,156 men and 9084 women). The stomach was the most common cancer incidence site for both men (25.6%) and women (18.6%). The leading cause of death was cancer among men (35.0%) and cardiovascular disease among women (41.0%).

    Conclusions: The Three-Prefecture Cohort Study enabled us to reveal the association of multiphasic lifestyle factors with cancer incidence and mortality. The study will also allow us to conduct a pooled analysis in combination with other large-scale cohorts.

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