[Abstract translation] J Epidemiol, 31(1); 2021

To grasp the big picture in limited time and survey current topics across the field, I translate the titles and abstracts of the open-access Journal of Epidemiology (the journal of the Japan Epidemiological Association) into Japanese. Since the goal is a quick overview, I post the outputs from DeepL largely as they are.

Update (May 8, 2021)

I found out that official Japanese highlights can be read here.

You can read the monthly Japanese highlights of the Japan Epidemiological Association's English journal (Journal of Epidemiology) here. I didn't know that. https://t.co/aHUkv0PPX0

— Shoei (@shoei05) May 8, 2021

Volume 31(1);  2021

https://www.ncbi.nlm.nih.gov/pmc/issues/370821/

Special Article

History and profile of Diagnosis Procedure Combination (DPC): Development of a real data collection system for acute inpatient care in Japan

Hayashida, Kenshi, et al. “History and Profile of Diagnosis Procedure Combination (DPC): Development of a Real Data Collection System for Acute Inpatient Care in Japan.” Journal of Epidemiology (2020): JE20200288.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738645/

DPC stands for "Diagnosis Procedure Combination" and is a patient classification method developed in Japan for acute inpatients. It was developed as a measurement tool to make acute inpatient care transparent and to standardize, evaluate, and improve the quality of medical care in Japan. Subsequently, this classification system came to be used for the medical fee payment system for acute inpatient care and the appropriate allocation of medical resources. More recently, it has also contributed to the development and maintenance of appropriate regional healthcare delivery systems based on the DPC data used for patient classification. This article first provides an overview of DPC. Next, it looks back on more than 15 years of DPC history, exploring in particular how DPC has been refined into an appropriate medical fee payment system. Finally, it introduces an overview of DPC-related research, including studies using DPC data.

Original Articles

Impact of PSCA polymorphisms on the risk of duodenal ulcer

Usui, Yoshiaki, et al. “Impact of PSCA Polymorphisms on the Risk of Duodenal Ulcer.” Journal of Epidemiology (2019): JE20190184.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738644/

Background
Duodenal ulcer (DU) and gastric cancer (GC) are both diseases associated with H. pylori infection, but DU patients are known to have a lower risk of GC. Many epidemiological studies have identified the PSCA rs2294008 T-allele as a risk factor for GC, while other studies have revealed an association between the rs2294008 C-allele and the risk of DU and gastric ulcer (GU). However, following these initial reports, few studies have validated these associations. This study aimed to validate the association between PSCA variants and DU/GU risk and to evaluate interactions with environmental factors in a Japanese population.

Methods
We genotyped six PSCA SNPs in 584 DU cases, 925 GU cases, and 8,105 controls from the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study. Unconditional logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between SNPs and DU/GU risk.

Results
The PSCA rs2294008 C-allele was associated with DU risk, with an allelic OR of 1.34 (95% CI, 1.18–1.51; P = 2.28×10-6). This association was independent of age, sex, study site, smoking habits, drinking habits, and H. pylori status. On the other hand, no association was observed between GU risk and PSCA SNPs.

Conclusions
Our study confirmed the association between the PSCA rs2294008 C-allele and the risk of DU in a Japanese population.

Vegetable and fruit intake and the risk of cataract incidence in a Japanese population: The Japan Public Health Center-based Prospective Study

Adachi, Sayaka, et al. “Intake of Vegetables and Fruits and the Risk of Cataract Incidence in a Japanese Population: The Japan Public Health Center-Based Prospective Study.” Journal of Epidemiology (2019): JE20190116.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738640/

Background
Vegetable and fruit intake has been reported to affect the risk of cataract, but no prospective studies from Asia have yet emerged on this association. Here, we examined the association between vegetable and fruit intake and cataract incidence in a large population-based prospective cohort study in Japan.

Methods
This study included 32,387 men and 39,333 women aged 45–74 years with no history of cataract who completed a dietary questionnaire in the Japan Public Health Center-based Prospective Cohort Study. Cataract incidence was assessed after a 5-year follow-up. Multiple logistic regression analysis was used to estimate sex-specific odds ratios (ORs), adjusting for confounding factors.

Results
We confirmed 1,836 incident cases of cataract in 594 men and 1,242 women. In men, higher vegetable intake was associated with a decreased OR for cataract (ORQ5 vs Q1, 0.77; 95% confidence interval [CI], 0.59–1.01; Ptrend across quartile categories = 0.03). In contrast, in women, the OR for cataract increased with higher vegetable intake (ORQ5 vs Q1, 1.28; 95% CI, 1.06–1.53; Ptrend = 0.01). Intakes of green and yellow vegetables and fruits were not associated with cataract in either sex.

Conclusions
This study suggests that vegetables may lower the risk of cataract in men, but not in women.

Alcohol consumption and the risk of gastric cancer: The Japan Collaborative Cohort Study

Li, Yuting, et al. “Alcohol Consumption and Risk of Gastric Cancer: The Japan Collaborative Cohort Study.” Journal of Epidemiology (2019): JE20190304.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738647/

Background
Alcohol consumption is a potential risk factor for gastric cancer. However, results from cohort studies examining the relationship between alcohol consumption and gastric cancer risk in the Japanese population remain inconclusive.

Methods
A total of 54,682 Japanese men and women participating in the Japan Collaborative Cohort Study completed a questionnaire that included information on alcohol consumption. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results
During a median follow-up of 13.4 years, 801 cases of gastric cancer in men and 466 in women were reported. Alcohol consumption was associated with an increased risk of gastric cancer in men (compared with non-drinkers, HRs for former drinkers and current alcohol consumption categories of <23 g, 23 to <46 g, 46 to <69 g, and ≥69 g/d were 1.82; 95% CI, 1.38–2.42; 1.41; 95% CI, 1.10–1.80; 1.47; 95% CI, 1.17–1.85; 1.88; 95% CI, 1.48–2.38; and 1.85; 95% CI, 1.35–2.53, respectively; and 1.07; 95% CI, 1.04–1.10 per 10-g increment of alcohol consumption after excluding former drinkers). In men, associations were observed for both cardia and non-cardia gastric cancer (HRs for the highest alcohol consumption category were 9.96; 95% CI, 2.22–44.67 for cardia gastric cancer, and 2.40; 95% CI, 1.64–3.52 for non-cardia gastric cancer). However, no such trend was observed in women.

Conclusions
In Japanese men, alcohol consumption is associated with an increased risk of gastric cancer regardless of the anatomical site of the cancer.

Effects of edible seaweed (nori) on blood pressure in young Japanese children: An intervention study

Wada, Keiko, et al. “Effect of dietary nori (dried laver) on blood pressure in young Japanese children: an intervention study.” Journal of Epidemiology (2020): JE20190176.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738648/

Background
Few studies have examined the association between seaweed intake and blood pressure in children. We conducted an intervention study to investigate whether seaweed intake affects blood pressure.

Methods
The subjects were 4- to 5-year-old children attending a nursery school in Aichi Prefecture in 2010. Of the 99 children at the school, 89 (89.9%) were enrolled in this study. Edible laver (nori), which is widely consumed in Japan, was used as the dietary intervention. Children in the intervention group consumed 1.76 g/day of toasted nori in addition to their standard diet for 10 weeks. Children in the control group consumed their usual diet. Before the intervention and at week 10 of the intervention, the children's blood pressure was measured three consecutive times in a seated position using an automated sphygmomanometer. Changes in systolic blood pressure (SBP) and diastolic blood pressure (DBP) were compared between 55 children in the intervention group and 26 in the control group after adjusting for pre-intervention SBP and DBP.

Results
In boys, the change in SBP was -8.29 mmHg in the intervention group and +0.50 mmHg in the control group (P for difference in change = 0.051). The change in DBP was -6.77 mmHg in the intervention group and -0.05 mmHg in the control group (P for difference in change = 0.031). In girls, no difference in blood pressure changes was observed between the intervention and control groups.

Conclusions
Nori consumption lowered DBP in boys. Nori intake may have a preventive effect against elevated blood pressure in childhood.

Infant mortality rates in farming and unemployed households in Japanese prefectures: An ecological time-trend analysis, 1999–2017

Kanamori, Mariko, Naoki Kondo, and Yasuhide Nakamura. “Infant Mortality Rates for Farming and Unemployed Households in the Japanese Prefectures: An Ecological Time Trend Analysis, 1999–2017.” Journal of Epidemiology (2020): JE20190090.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738643/

Background
Recent studies suggest that inter-prefectural disparities in the risk of death before reaching age 5 have widened in Japan since the 2000s. However, no studies have examined recent trends in inequalities in the infant mortality rate (IMR) and associated socioeconomic characteristics. This study focused specifically on household occupation, environment, and perinatal parental support systems.

Methods
Using national vital statistics by household occupation for all 47 prefectures from 1999 to 2017, we conducted multilevel negative binomial regression analysis to assess the association between occupation and IMR, and joinpoint analysis to observe temporal trends. We also created thematic maps showing the geographical distribution of IMR.

Results
Compared with the most privileged occupation (Type II regular workers, including employees of companies with 100 or more employees), the infant mortality rate (IMR) ratio was 1.26 for Type I regular workers (including employees of companies with fewer than 100 employees), 1.41 for the self-employed, 1.96 for farming workers, and 6.48 for the unemployed. The IMR ratio for farming households was 1.75 (lowest) in prefectures with high population density and 1.41 (lowest) in prefectures with a high number of farming households per 100 households. Joinpoint regression also revealed that compared with Type II regular worker households, the IMR difference and ratio for farming households increased monotonically year by year. For the unemployed, the IMR difference increased sharply from 2009, and the ratio increased from 2012.

Conclusions
Inequalities in IMR across occupations in Japan increased from 1999 to 2017. Further research using individual-level data is needed to better understand the mechanisms that contributed to this increase.

Hospital surgical volume and 3-year mortality in severe prognosis cancers: A population-based study using cancer registry data

Taniyama, Yukari, et al. “Hospital Surgical Volume and 3-Year Mortality in Severe Prognosis Cancers: A Population-Based Study Using Cancer Registry Data.” Journal of Epidemiology (2020): JE20190242.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738649/

Background
Although esophageal, biliary tract, and pancreatic cancers require advanced medical expertise, the impact of hospital surgical volume on long-term mortality has not been thoroughly evaluated in Japan. This study aimed to examine the association between hospital surgical volume and 3-year mortality in patients with these poor-prognosis cancers.

Methods
Using data from the Osaka Cancer Registry from 2006 to 2013, we analyzed patients who underwent curative surgery for esophageal, biliary tract, and pancreatic cancers. Based on the average annual number of curative surgeries per hospital for each cancer, we categorized hospital surgical volume into three levels (high, medium, and low) and calculated 3-year survival rates using the Kaplan-Meier method. Hazard ratios (HRs) for 3-year mortality were calculated using Cox proportional hazards models adjusted for patient characteristics.

Results
Three-year survival rates were higher at hospitals with larger surgical volumes across all three cancers, though the relative importance of surgical volume varied by site. After adjusting for all confounding factors, the HRs for medium- and low-volume hospitals were 1.34 (95% confidence interval [CI], 1.14–1.58) and 1.57 (95% CI, 1.33–1.86) for esophageal cancer, 1.39 (95% CI, 1.15–1.67) and 1.57 (95% CI, 1.30–1.89) for biliary tract cancer, and 1.38 (95% CI, 1.16–1.63) and 1.90 (95% CI, 1.60–2.25) for pancreatic cancer, respectively. The impact of hospital surgical volume on 3-year mortality was particularly strong for localized pancreatic cancer (HR 2.66; 95% CI, 1.61–4.38).

Conclusion
These findings suggest that referring patients who require curative surgery for esophageal, biliary tract, or pancreatic cancer to high-volume hospitals is effective.

Relationship between urine proteinuria levels and the risk of developing gallstone disease

Park, Sung Keun, et al. “The Level of Urine Dipstick Proteinuria and Its Relation to the Risk of Incident Cholelithiasis.” Journal of Epidemiology (2020): JE20190223.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738639/

Background
Previous studies have suggested a potential association between kidney disease and gallstones. The degree of proteinuria is recognized as an indicator of the severity of chronic kidney disease. However, few data are available to determine the risk of gallstone development according to the degree of proteinuria.

Methods
Using data from 207,356 Koreans registered in the National Health Insurance database, we evaluated the risk of gallstones according to urine proteinuria levels over an average follow-up of 4.36 years. Subjects were divided into three groups based on their urine proteinuria levels (negative: 0, mild: 1+, and heavy: 2+ or higher). Multivariable Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for developing gallstone disease according to urine protein levels.

Results
The heavy urine proteinuria group had worse metabolic, renal, and hepatic function profiles than the non-proteinuria group, and similar results were observed in the group that developed gallstone disease. The incidence of gallstone disease was highest in the heavy proteinuria group (2.39%), followed by the mild group (1.54%) and the proteinuria-negative group (1.39%). Multivariable Cox proportional hazards analysis showed that the heavy proteinuria group had a higher risk of developing gallstone disease than the other groups (negative: reference; mild proteinuria: HR 0.97 [95% CI, 0.74–1.26]; heavy proteinuria: HR 1.46 [95% CI, 1.09–1.96]).

Conclusion
Urine proteinuria of 2+ or higher was significantly associated with an increased risk of developing gallstones.

Study Profile

Overview of the Tohoku Medical Megabank Community-Based Cohort Study

Hozawa, Atsushi, et al. “Study profile of The Tohoku Medical Megabank Community-Based Cohort Study.” Journal of Epidemiology (2020): JE20190271.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738642/

Background
We established a community-based cohort study to evaluate the long-term impact of the Great East Japan Earthquake on disaster survivors and the gene-environment interactions affecting the incidence of major diseases such as cancer and cardiovascular disease.

Methods
Participants were recruited into the cohort through health checkup sites and assessment centers. Eligibility criteria included residents of Miyagi or Iwate Prefecture aged 20 years or older. We collected information on lifestyle habits, disaster impacts, and blood and urine data (Type 1 survey), as well as detailed measurements such as carotid ultrasound and calcaneal ultrasound bone mineral density (Type 2 survey). All participants consented to genomic analysis and the broad sharing of their data.

Results
A total of 87,865 individuals gave informed consent and participated in the study. The participation rate at health checkup sites was approximately 70%. Type 1 survey participants were more likely to experience psychological distress than Type 2 survey participants, and women were more likely to experience psychological distress than men. Furthermore, regardless of sex, residents in coastal areas had higher levels of psychological distress than those in inland areas.

Conclusion
This cohort has a large sample size and includes natural disaster data, genomic data, and metabolomic data, alongside several detailed physiological measurements. Using this cohort makes it possible to clarify the long-term impacts of the disaster and establish personalized preventive measures based on genomic, metabolomic, and other omics data.

Implementation of the Adachi Child Health Impact of Living Difficulty (A-CHILD) study: research protocol and participant profile

Ochi, Manami, et al. “Adachi Child Health Impact of Living Difficulty (A-CHILD) study: research protocol and profiles of participants.” Journal of Epidemiology (2020): JE20190177.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738641/

Background
The Adachi Child Health Impact of Living Difficulty (A-CHILD) study has been conducted since 2015 to clarify the association between socioeconomic factors and child health and to accumulate data for policy evaluation on child poverty. This paper describes the objectives and study design of the A-CHILD study, the baseline profile of participants, and the future framework for conducting this cohort study.

Methods
We conducted two types of ongoing surveys: a complete-sample longitudinal survey started in 2015 as the first wave targeting all first-grade students in public elementary schools in Adachi Ward, Tokyo, and a biennial fixed-grade repeated cross-sectional survey started in 2016 targeting selected elementary and junior high schools. Caregivers of all target children completed questionnaires, and children in the fourth grade and above also completed self-administered questionnaires. In addition, A-CHILD data are linked with school health checkup records for all participating grades, as well as blood test and blood pressure measurement results for second-year junior high school students conducted since 2016.

Results
Valid responses in the first wave totaled 4,291 (80.1%). A total of 1,047 households (24.5%) were experiencing "living difficulties," defined as low household income or material deprivation.

Conclusion
The A-CHILD study will help clarify the impact of poverty on child health disparities and pave the way for managing this issue within the local community.

Letters to the Editor

Excess all-cause mortality during the COVID-19 outbreak in Japan

Yorifuji, Takashi, Naomi Matsumoto, and Soshi Takao. “Excess All-Cause Mortality During the COVID-19 Outbreak in Japan.” Journal of Epidemiology (2020): JE20200492.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738637/

Deterioration of mental health during repeated COVID-19 outbreaks is greatest among individuals with low educational attainment: a cohort study of Japanese employees

Sasaki, Natsu, et al. “Deterioration in Mental Health Under Repeated COVID-19 Outbreaks Greatest in the Less Educated: A Cohort Study of Japanese Employees.” Journal of Epidemiology (2020): JE20200499.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738638/

Urgent need for guidelines on using preprints as an information source

Ide, Kazuki, et al. “Guidelines are urgently needed for the use of preprints as a source of information.” Journal of Epidemiology (2020): JE20200506.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738646/