Japan Nurses’ Health Study (Japan)

Field Names
Records
Coordinating Country
Japan
Region

Japan

Brief Database Description

The Japan Nurses’ Health Study (JNHS) is a prospective cohort investigation of the effects of lifestyle and healthcare on women’s health. The primary purposes of the JNHS are to describe the status of lifestyle, healthcare practice, and physical status of Japanese women, to estimate the effects of those factors on their health, and to establish evidence regarding the risk-benefits of long-term administration of women-specific health management such use of exogenous hormones.

The study was initiated in 2001 with a six-year entry period and a ten-year follow-up. The study population comprises female registered nurses, licensed practical nurses, public health nurses, and midwives, aged 25 years or more at baseline survey. The participants were recruited in cooperation with the Japan Menopause Society and the Japanese Nursing Association.

The secondary purposes of the study are to investigate occupational health among Japanese nurses, and to evaluate the effects of shift work and work-related stress on women’s health.

The study involves a self-administered baseline questionnaire that solicited demographic information, lifestyle, pharmaceutical drug use, physical condition, reproductive health, and disease history, with a list of photographs of female hormone drugs. The baseline survey was completed in 2007, and 49,997 women responded from all 47 prefectures of Japan. Among the respondents, approximately 17,000 women, who agreed to be followed-up, returned signed informed consent sheets with completed baseline questionnaires. Changes in lifestyle, healthcare, incidence of disease, and health outcome over time will be studied. The cohort receives annual JNHS newsletters and biennial follow-up questionnaires by mail.

Database Type
Longitudinal Population Database

Longitudinal Population Survey
(The Japan Nurses’ Health Study (JNHS) is a prospective cohort investigation of the effects of lifestyle and healthcare on women’s health. The study was initiated in 2001 with a six-year entry period and a ten-year follow-up. The study population comprises female registered nurses, licensed practical nurses, public health nurses, and midwives, aged 25 years or more at baseline survey. The participants were recruited in cooperation with the Japan Menopause Society and the Japanese Nursing Association.

The study involves a self-administered baseline questionnaire that solicited demographic information, lifestyle, pharmaceutical drug use, physical condition, reproductive health, and disease history, with a list of photographs of female hormone drugs. The baseline survey was completed in 2007, and 49,997 women responded from all 47 prefectures of Japan. Among the respondents, approximately 17,000 women, who agreed to be followed-up, returned signed informed consent sheets with completed baseline questionnaires. Changes in lifestyle, healthcare, incidence of disease, and health outcome over time will be studied. The cohort receives annual JNHS newsletters and biennial follow-up questionnaires by mail.)

Database Source
Case Report Forms
Survey Data
Frequency of Data Collection
Other

(Biennially)

Frequency of Data Update
Other

(Biennially)

Years Covered
2001 - Present
Population Type
Other

(Female registered nurses, licensed practical nurses, public health nurses, and midwives, aged 25 years or more at baseline survey)

Patient Type
Outpatient/Non-Institutionalized
Date of Last Update
Ongoing

(The Japan Nurses’ Health Study is updated on an ongoing basis;
This profile was developed for the B.R.I.D.G.E. TO DATA site on June 16, 2022.)

Field Names
Records
Database Population Size
<200,000

(49,927 participants. Among the respondents, approximately 15,000 women agreed to participate in the follow-up surveys.)

Active Population Size
<200,000

A total of 15,019 participants are continuing the study

Annual Change in Population
N/A

(Not applicable)

Sample Weights - Extrapolation Factors
No
Final Population Size
N/A

(Not applicable, as data are still being collected from the 15,019 participants who are continuing the study)

Field Names
Records
Age of Patients at Data Collection
Yes

DOB is collected.
The study population was designed for female registered nurses, licensed practical nurses, public health nurses, and/ or midwives, who were at least 30 years of age and resident in Japan at the baseline survey. The age limit was reduced to 25 years in 2005.

Approximate Percentage of Participants <18 years and those >65 years

< 18 = 0%
> 65 = 0.8%

At Enrollment:
between 30-34: 22.5%
between 35-39: 20.5%
between 40-44: 9.5%
between 45-49: 6.4%
between 50-54: 12.0%
between 55-59: 4.4%
> 60: 0.8%

Gender Data
Yes
Percentage of Males/Females

Females = 100%
Males = 0%

Ethnicity / Race Data
Yes

Asian: Japanese

Geographic Location

Japan

Date of Birth Recorded
Yes
Death Recorded
Yes

Limited records: death from cardiovascular diseases (myocardial infarction, coronary heart disease, subarachnoid hemorrhage, cerebral infarction, cerebral hemorrhage) identified by the death certificates from the National Vital Statistics

Availability of death certificate / autopsy information
Yes
Other Demographic Data
Yes

Including:
- Birth place,
- Marital status,
- Education,
- Nursing qualification,
- Employment position,
- Place of employment,
- History of shift work.

Field Names
Records
Physician ID
N/A

(Not applicable)

Physician Specialty
N/A

(Not applicable)

Pharmacy ID
N/A

(Not applicable)

Field Names
Records
Diagnosis Data
Yes

This includes:
1. Self-reported diagnosed diseases in regular follow-up questionnaires
2. Additional confirmation questionnaires for self-reported cases
3. Cause of death in the Death Certificate
4. JNHS committee criteria

Diagnoses Coded
ICD-10
Diagnoses: Date Parameters
2001 - Present
Diagnoses: Maximum Number of Codes Allowed
Unlimited
Physical Examination Findings
Yes

Current weight, weight at birth, weight at age 18, height

Birth Defect Data
N/A

(Not applicable)

Cancer Data
Yes

(Cervical cancer, endometrial cancer, ovarian cancer, breast cancer, gastric cancer, colon-rectal cancer)

Infectious Disease Data
Yes

Information is collected on HPV, SARS-Cov-2, and vaccinations

Environmental Exposures
Yes

(Effect of night-shift work)

Behavioral Data Elements
Yes

Smoking, alcohol consumption, physical exercise, food

Field Names
Records
Procedure Data
No
Procedures Coded
N/A

(Not applicable)

Number of Procedures Coded
N/A

(Not applicable)

Procedure Date Parameters
N/A

(Not applicable)

Laboratory Information
Yes

Laboratory information is available on blood pressure, total serum cholesterol, HDL-cholesterol, FBS, HbA1c

Field Names
Records
Drug Data
Yes: Prescription & OTC
Drug Date Parameters
2001 - Present
Drug Regimen & Route
Yes
Drug Manufacturer
No
Drug Dosage
Yes
Drug Days Supply
Yes
Drug Coding System: Maximum Number
Yes
Drug Coding System: Primary
Other

(They use their own proprietary drug coding system)

Drug Coding System: Other
N/A

(Not applicable)

Drug Generic Name
Yes
Drug Additional Information
N/A

(Not applicable)

Field Names
Records
Biobank Type
N/A
Human Specimen
N/A
Blood Type
N/A
Biomarkers
N/A
Patient ID
N/A
Number of Samples
N/A
Frequency of Sample Collection
N/A
Pre-diagnostic Sample Collection
N/A
Post-treatment Sample Collection
N/A
Method of Sample Collection
N/A
Age at Sample Collection
N/A
Date of Sample Collection
N/A
Reason for Sample Collection
N/A
Method of Sample Storage
N/A
Length of Sample Storage
N/A
Pathology
N/A
DNA Isolation
N/A
RNA Isolation
N/A
Cell Culture
N/A
Genetic Testing
N/A
Access for Research: Specimens
N/A
Access for Research: Genetic Data
N/A
Access for Research: Epidemiologic Data
N/A
Quality Assurance Procedures
N/A
Family History
N/A
Medical History
N/A
Biobank Linkage
N/A
Field Names
Records
Type of Genetic Database
N/A
Source of Genetic Data
N/A
Specimen Genotyped
N/A
Tissue Form
N/A
Genetic Template
N/A
Gene-Drug Response
N/A
Gene-Disease Relationship
N/A
Gene-Health Outcome Relationship
N/A
Gene-Environment Response
N/A
Method of Imputing Genetic Data
N/A
Genetic Variant Identification
N/A
Genetic Data Level
N/A
Genotyping Method
N/A
Method of Genetic Variant Filtering
N/A
Haplotypes
N/A
Haplogroups
N/A
Variable Number of Tandem Repeats (VNTR)
N/A
Single Nucleotide Polymorphisms (SNPs)
N/A
Variant Type
N/A
Variant Class
N/A
Mutation Indicated
N/A
Position
N/A
Amino Acid Change
N/A
Genotype / Polymorphism
N/A
Allele Frequency
N/A
Linkage Disequilibrium (r²)
N/A
Noncarriers Indicated
N/A
Association Statistics
N/A
Genetic Relatedness Pairing
N/A
Data Sharing: Genetic Data
N/A
Access for Research
N/A
Genetic Data Linkage
N/A
Description of Genetic Data Linkage
N/A
Field Names
Records
Cost Data
No
Cost Denomination
N/A

(Not applicable)

Type of Cost Data
N/A

(Not applicable)

Surrogate Cost Data Link
No
Description of Surrogate Link
N/A

(Not applicable)

Field Names
Records
Data Validation Against Original Source
Yes

Moreover, for most diseases, self-reported information is confirmed with additional questionnaires and medical records by the sub-studies implemented by the JNHS Validation Study Committee

Access to Medical Records
No
Linkage to Other Databases
No
Brief Description of Linkage Capabilities

N/A

(Not applicable)

Field Names
Records
Database Contact Data

Principal Investigator - 
Kunihiko Hayashi, PhD
Executive Director of Education and Evaluation 
Vice-President, Gunma University
4-2 Aramaki
Maebashi
Gunma 371-8510
JAPAN
Tel: (+81) 27-220-7112
Fax: (+81) 27-220-7535 
Email: khayashi@gunma-u.ac.jp 

Website
https://plaza.umin.ac.jp/~jnhs/eng/
Alternate Contact

Email: jnhs.jimu@gmail.com

Source of Database Funding
Government
Sponsoring Government Agency
1. Department of Basic Allied Medicine, School of Health Sciences, Gunma University

2. Department of Obstetrics and Gynecology, Hirosaki University School of Medicine

3. Department of Data Science, The Institute of Statistical Mathematics

4. Gunma Occupational Health Promotion Center, Gunma Medical Center

5. Center for Cancer Control & Information Services, National Cancer Center

6. Information Center, National Institute of Health and Nutrition

7. Department of Comprehensive Reproductive Medicine, Tokyo Medical and Dental University
Sponsoring Pharmaceutical Manufacturer

N/A

(Not applicable)

Database Usage Restrictions
Private Access

Access is restricted to JNHS researchers only

Charge for Database Usage
N/A

(Not applicable, as access is restricted to JNHS researchers only)

Data Media Format
N/A

(Not applicable, as access is restricted to JNHS researchers only)

Number of Publications Using Database
< 10
References of Studies Using/Describing Database

1. Yasui T, Ideno Y, Shinozaki H, Kitahara Y, Nagai K, Hayashi K. Prevalence of the Use of Oral Contraceptives and Hormone Replacement Therapy in Japan: The Japan Nurses' Health Study. J Epidemiol. 2022 Mar 5;32(3):117-124.

2. Katanoda K, Ideno Y, Maruoka N, Nagai K, Tsukada Y, Matsuki M, Higashi T, Hayashi K. Validation of Identifying Cancer Diagnosis Based on Self-Reported Information in the Japan Nurses' Health Study. Asian Pac J Cancer Prev. 2022 Feb 1;23(2):651-657.

3. Nagai K, Homma Y, Ideno Y, Hayashi K. Prevalence and factors associated with overactive bladder and stress urinary incontinence in the Japan Nurses' Health Study. Menopause. 2021 Dec 13;29(2):129-136.

4. Ri M, Hayashi K, Kurabayashi T, Lee JS, Ideno Y, Nagai K, Yasui T, Kubota T, Takamatsu K. Hypertensive disorders of pregnancy increase the risk of future menopausal hot flashes in Japanese women: results from the Japan Nurses' Health Study. Menopause. 2021 Oct 25;29(2):164-169.

5. Kurabayashi T, Mizunuma H, Kubota T, Nagai K, Hayashi K. Low birth weight and prematurity are associated with hypertensive disorder of pregnancy in later life: a cross-sectional study in Japan. Am J Perinatol. 2021 Aug;38(10):1096-102.

6. Takamatsu K, Ideno Y, Kikuchi M, Yasui T, Maruoka N, Nagai K, Hayashi K. Validity of self-reported diagnoses of gynaecological and breast cancers in a prospective cohort study: the Japan Nurses' Health Study. BMJ Open. 2021 Jun 18;11(6):e045491.

7. Taguchi A, Nagai K, Ideno Y, Kurabayashi T, Hayashi K. Parity and number of teeth present in Japanese women: Results from the Japan Nurses’ Health Study. Women’s Health Reports 2020 Dec; 1(1): 366-74.

8. Ito A, Hayashi K, Suzuki S, Ideno Y, Kurabayashi T, Ogata T, Seichi A, Akai M, Iwaya T. Association of trajectory of body mass index with knee pain risk in Japanese middle-aged women in a prospective cohort study: The Japan Nurses’ Health Study. BMJ Open 2020 Feb; 10: e033853.

9. Katanoda K, Noda M, Goto A, Mizunuma H, Lee JS, Hayashi K. Being underweight in adolescence is independently associated with adult-onset diabetes among women: The Japan Nurses' Health Study. J Diabetes Investig. 2019 May;10(3):827-836.

10. Alkebsi L, Ohnishi H, Nakajima-Shimada J, Onizuka Y, Ideno Y, Sato Y, Hayashi K. Validation of the Accuracy of Self-Reported ABO Blood Types in the Japan Nurses’ Health Study. Asian Pac J Cancer Prev. 2019 Mar 26;20(3):789-793.

Database Contact
Database Contact Data

Principal Investigator - 
Kunihiko Hayashi, PhD
Executive Director of Education and Evaluation 
Vice-President, Gunma University
4-2 Aramaki
Maebashi
Gunma 371-8510
JAPAN
Tel: (+81) 27-220-7112
Fax: (+81) 27-220-7535 
Email: khayashi@gunma-u.ac.jp 

Alternate Contact

Email: jnhs.jimu@gmail.com

References of Studies Using/Describing Database

1. Yasui T, Ideno Y, Shinozaki H, Kitahara Y, Nagai K, Hayashi K. Prevalence of the Use of Oral Contraceptives and Hormone Replacement Therapy in Japan: The Japan Nurses' Health Study. J Epidemiol. 2022 Mar 5;32(3):117-124.

2. Katanoda K, Ideno Y, Maruoka N, Nagai K, Tsukada Y, Matsuki M, Higashi T, Hayashi K. Validation of Identifying Cancer Diagnosis Based on Self-Reported Information in the Japan Nurses' Health Study. Asian Pac J Cancer Prev. 2022 Feb 1;23(2):651-657.

3. Nagai K, Homma Y, Ideno Y, Hayashi K. Prevalence and factors associated with overactive bladder and stress urinary incontinence in the Japan Nurses' Health Study. Menopause. 2021 Dec 13;29(2):129-136.

4. Ri M, Hayashi K, Kurabayashi T, Lee JS, Ideno Y, Nagai K, Yasui T, Kubota T, Takamatsu K. Hypertensive disorders of pregnancy increase the risk of future menopausal hot flashes in Japanese women: results from the Japan Nurses' Health Study. Menopause. 2021 Oct 25;29(2):164-169.

5. Kurabayashi T, Mizunuma H, Kubota T, Nagai K, Hayashi K. Low birth weight and prematurity are associated with hypertensive disorder of pregnancy in later life: a cross-sectional study in Japan. Am J Perinatol. 2021 Aug;38(10):1096-102.

6. Takamatsu K, Ideno Y, Kikuchi M, Yasui T, Maruoka N, Nagai K, Hayashi K. Validity of self-reported diagnoses of gynaecological and breast cancers in a prospective cohort study: the Japan Nurses' Health Study. BMJ Open. 2021 Jun 18;11(6):e045491.

7. Taguchi A, Nagai K, Ideno Y, Kurabayashi T, Hayashi K. Parity and number of teeth present in Japanese women: Results from the Japan Nurses’ Health Study. Women’s Health Reports 2020 Dec; 1(1): 366-74.

8. Ito A, Hayashi K, Suzuki S, Ideno Y, Kurabayashi T, Ogata T, Seichi A, Akai M, Iwaya T. Association of trajectory of body mass index with knee pain risk in Japanese middle-aged women in a prospective cohort study: The Japan Nurses’ Health Study. BMJ Open 2020 Feb; 10: e033853.

9. Katanoda K, Noda M, Goto A, Mizunuma H, Lee JS, Hayashi K. Being underweight in adolescence is independently associated with adult-onset diabetes among women: The Japan Nurses' Health Study. J Diabetes Investig. 2019 May;10(3):827-836.

10. Alkebsi L, Ohnishi H, Nakajima-Shimada J, Onizuka Y, Ideno Y, Sato Y, Hayashi K. Validation of the Accuracy of Self-Reported ABO Blood Types in the Japan Nurses’ Health Study. Asian Pac J Cancer Prev. 2019 Mar 26;20(3):789-793.