About the fifteenth wave of the survey (JHPS2023)

The fifteenth wave of the survey (Continuous Cohort)

- Survey Date: The survey was implemented on 31 January 2023.
- Survey Subjects: The 1,349 individuals who were subjects of the JHPS fourteenth wave
(Valid respondents: 1,300 individuals, and 49 individuals who did not respond to JHPS fourteenth wave but who wished to participate in the survey.)
- Survey Method: The survey was implemented by the drop-off pick-up (DOPU) method and on the web (only for those who wish). Due to the spread of the COVID-19, if investigators did not wish to distribute the questionnaires, they were distributed and returned by mail.
- Types of Questionnaires: Two types of questionnaires that differed according to whether there was a spouse or not were used. And another questionnaire for spouse who married with respondent in the past year.
- Collection rate: Of 1,300 individuals who were surveyed, 1,185 individuals responded the survey, and then the collection rate was 91.2 %.
22 respondents who did not respond to the survey last year cooperated in the survey this year.

JHPS fifteenth wave responses

Number of samples	1,349
Completed	1,207
Of which last respondent	1,185
Of which Revival	22
Recovery rate*	91.2%
Married	884
Single	323
Newlywed	1
Dropout	142

*Recovery rate = (Completed－Revival) / Completed in last year × 100

■ 15th wave (JHPS2023) questionnaire PDF
* From 2022 the contents of the JHPS original cohort (JHPS2009) survey questionnaire and the JHPS top-up cohort (JHPS2019) survey questionnaire are the same.

The fifteenth wave of the survey (2019 New Cohort)

- Survey Date: The survey was implemented on 31 January 2023.
- Survey Subjects: The 1,390 individuals who were subjects of the JHPS fourteenth wave
(Valid respondents: 1,259 individuals, and 131 individuals who did not respond to JHPS fourteenth wave but who wished to participate in the survey.)
- Survey Method: The survey was implemented by the drop-off pick-up (DOPU) method and on the web (only for those who wish). Due to the spread of the COVID-19, if investigators did not wish to distribute the questionnaires, they were distributed and returned by mail.
- Types of Questionnaires: Two types of questionnaires that differed according to whether there was a spouse or not were used. And another questionnaire for spouse who married with respondent in the past year.
- Collection rate: Of 1,259 individuals who were surveyed, 1,086 individuals responded the survey, and then the collection rate was 86.3 %.

JHPS fifteenth wave collection rate (2019 New Cohort)

Number of samples	1,390
Completed	1,139
Of which last respondent	1,086
Of which Revival	53
Recovery rate	86.3 %
Married	721
Single	418
Newlywed	14
Dropout	251

The fifteenth wave of the survey (2023 New Cohort)

- Coverage of the Survey

Males and females aged between 20 years and over as of 31 January 2023.
(Males and females born before January 2003).
According to the population estimates for January 2022, there were 102.88 million people in this group and it constituted 83.5% of the total population of Japan.

- Survey Date

The survey was implemented on 4 March 2023.

- Selection of survey respondents

(1) Sample Size
1,432 individuals
20~24 years old: 306 respondents, 25~34 years old: 345 respondents, 35~44 years old: 141 respondents, 45~54 years old: 104 respondents, 55~64 years old: 0 respondents, 65 years old or over: 536 respondents
(2) Method for Sampling
Two-stage stratified sampling (1st stage: survey area, 2nd stage: individual)

(3) Selection of areas surveyed
First, the whole country was stratified into 24 strata by region and city class, and then, the sample size for each stratum was determined by each stratum’s share of the population based on the National Residents Register as of January 1, 2022.
Next, survey areas in each stratum were selected at random. The number of survey areas was determined for each stratum based on the assumption that approximately 4 people would be selected to be surveyed in each area.

Details of the allocation of the sample across regions and city class are as follows

	Large Cities	Other Cities	Towns and Villages	Total
Hokkaido	23	26	10	59
Tohoku	12	68	17	97
Kanto	208	272	20	500
Chubu	52	182	24	258
Kinki	75	147	12	234
Chugoku	21	55	6	82
Shikoku	-	35	6	41
Kyushu	39	101	21	161
Total	430	886	116	1432

(4) Selection of Survey Respondents
For each survey area, approximately 4 people were selected to be surveyed based on the National Residents Register. Selected respondents were restricted to eligible individuals. As for the detail of selection process, from a certain point on the National Residents Register, individuals listed were selected using a fixed interval.
(5) Choice of the reserve subjects
In order to obtain a sample of 1,432 individuals, originally selected subjects that did not take part in the survey were replaced by individuals who were previously selected as reserve subjects.
The reserve subjects were selected to have the same sex (male or female), and the same age grouping (in their 20~24 years old, 25~34 years old, 35~44 years old, 45~64 years old, 65 years old or more over) as the original individual.

- Survey Method

The survey was implemented by the drop-off pick-up (DOPU) method. The surveyor distributed the questionnaire to the survey respondent, and later the surveyor revisited the respondent to collect the questionnaire that had been completed by the respondent. For this group, the survey is totally self-administered.

- Types of Questionnaires

Two types of questionnaires that differed according to whether there was a spouse or not were used.

JHPS fifteenth wave collection rate (2023 New Cohort)

Completed	1,735
Married	832
Single	903

■ 15th wave (JHPS2023) questionnaire (2023 New Cohort) PDF

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