DOI: 10.3886/icpsr36427.v1
title: Survey of Midlife in Japan (MIDJA 2), May-October 2012
title: Version 1

description: In 2008, with funding from the National Institute on Aging (NIA), baseline survey data for the Survey of Midlife in Japan (MIDJA), April-September 2008 were collected from a probability sample of Japanese adults (N=1,027) aged 30 to 79 from the Tokyo metropolitan area (ICPSR 30822). In 2009-2010 biomarker data was obtained from a subset of these cases (ICPSR 34969).
The survey and biomarker measures obtained parallel those in a national longitudinal sample of Americans known as Midlife in the United States or MIDUS (ICPSR 2760: MIDUS 1 and ICPSR 4652: MIDUS 2). The central objective was to compare the Japanese sample (MIDJA) with the United States sample (MIDUS) to test hypotheses about the role of psychosocial factors in the health (broadly defined) of mid- and later-life adults in Japan and the United States.
In 2012, with additional support from NIA, a longitudinal follow-up of the MIDJA sample was completed. The data collection for this second wave (N=657) largely repeated the baseline assessments. The goal of the follow-up wave was to conduct comparisons of longitudinal data available from the Japanese sample (MIDJA) and the United States sample (MIDUS) to test the hypothesis about the role of psychosocial factors in predicting health changes (including biomarkers) in both cultural contexts. Cultural influences on age differences in health and well-being were also of interest.
Demographic and background information included gender, age, education, marital status, household composition, and income.
description: The overarching goal of the MIDJA (Midlife in Japan) study was to conduct a multidisciplinary study of health and well-being in a sample of middle- and older-aged Japanese adults. A first primary aim was to collect survey data on a probability sample of adults from the city of Tokyo, Japan. A second aim was to recruit a subsample of respondents from the above survey to participate in a related biomarker study (to be released for public use at a later date).
description: The initial, baseline, data collection occurred in two phases. The first phase, survey data collection was conducted by Central Research Services (CRS), a survey research firm based in Tokyo. Following the convention of social surveys in Japan, the "deliver-and-pick-up" method was used for data collection Participants in the second phase, a subset of those completing the survey, completed biomarker and other assessments in a local clinic as well as at home (saliva samples, questionnaire).
The overarching goal of the Midlife Health in Japan (MIDJA) study was to conduct a multidisciplinary study of health and well-being in a sample of middle- and older-aged Japanese adults. The design and scientific content of the study were comparable to an ongoing longitudinal study in the U.S., known as MIDUS (Midlife in the U.S.). Parallels between the two provide unique opportunities to investigate how cultural differences in self and relational factors predict life course variations in well-being and health.
Funding for a longitudinal follow-up was obtained in February 2012. This second wave of data collection also occurred in two phases. The first phase, survey data collection, was conducted by Shin Joho Center, a survey research firm based in Tokyo. Consistent with the baseline data collection the "deliver-and-pick-up" convention was once again followed. Participants in the second phase, biomarker assessments, once again completed biomarker assessments in a local clinic as well as at home.
description: This collection includes information about the following types of variables: health, cigarettes, alcohol, emotion or feelings, work, finances, personal beliefs, social network, neighborhood, life overall, friends, marriage or close relationship, children, family, religion and spirituality, parents' health, and scale variables.
description: ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of 
				disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major 
				statistical software formats as well as standard codebooks to accompany the data. In addition to 
				these procedures, ICPSR performed the following processing steps for this data collection:
			   		Created online analysis version with question text.; Checked for undocumented or out-of-range codes..
description: Presence of Common Scales: 
					Please refer to the "Documentation of Scales and Constructed Variables in MIDJA 2" for complete information regarding the scales for the MIDJA data collection.
description: Response Rates: 
					The response rate for the longitudinal follow-up is 73.7 percent.  Reasons for nonresponse included: moved, address unknown, absent during time of survey, illness/injury, hospitalized, deceased. Detailed information regarding the response rates for various aspects of the MIDJA data collection is located in the "MIDJA Study Summary."
description: Datasets: 
					
						DS1: Survey of Midlife Development in Japan (MIDJA 2), May-October 2012
description: Midlife in the United States (MIDUS) Series
description: mail questionnaire
description: self-enumerated questionnaire
description: Noninstitutionalized, Japanese-speaking adults, who completed the MIDJA baseline survey (ICPSR 30822) in April 2008-September 2008.
				   		Smallest Geographic Unit: none
description: All respondents who completed the baseline MIDJA Survey were eligible to participate in this longitudinal follow-up.