SAGE
WHO Study on global AGEing and adult health (SAGE)
SAGE Cohorts: 2002-2011, Background and Objectives
The WHO Multi-Country Studies unit developed the Study on Global AGEing and Adult Health (SAGE) as part of a Longitudinal Survey Programme to compile comprehensive longitudinal information on the health and well-being of adult populations and the ageing process. The core SAGE collects data on respondents aged 18+ years, with an emphasis on populations aged 50+ years, from nationally representative samples in six countries (China, Ghana, India, Mexico, Russian Federation and South Africa). The survey instruments and methods described on this website were adapted from those used by the World Health Survey (WHS) and/or from 16 surveys on ageing (including the US Health and Retirement Survey (HRS) and the UK English Longitudinal Study of Ageing (ELSA)).
Household and individual level data on persons aged 50+ years are available from 20 countries as part of the core SAGE, the World Health Survey Plus (WHS+), COURAGE and SAGE-INDEPTH. SAGE has pursued cross-study comparisons and analyses with other data collection efforts such as the Study on Health, Ageing and Retirement in Europe (SHARE) and demographic surveillance fieldsites in INDEPTH. The health and vignettes questions in the SHARE self-completed vignettes questionnaire were drawn from SAGE and were implemented in an additional 11 countries. Eight INDEPTH HDSS fieldsites have implemented an abbreviated SAGE instrument, and three HDSS completed the full SAGE in a small sample of respondents aged 50+ years. Survey tools for SAGE-INDEPTH and SHARE are available through this website (click on link, "3. Additional SAGE Data and Methods"), with data available on request.
This study and survey programme is supported by the Division of Behavioral and Social Research at the National Institute on Aging, National Institutes of Health, USA through an Interagency Agreement and a Research Project Grant 1 R01 AG034479-01A1.
Primary Objectives
- To obtain reliable, valid and comparable health, health-related and well-being data over a range of key domains for adult and older adult populations in nationally representative samples
- To examine patterns and dynamics of age-related changes in health and well-being using longitudinal follow-up of a cohort as they age, and to investigate socio-economic consequences of these health changes
- To supplement and cross-validate self-reported measures of health and the anchoring vignette approach to improving comparability of self-reported measures, through measured performance tests for selected health domains
- To collect health examination and biomarker data that improves reliability of morbidity and risk factor data and to objectively monitor the effect of interventions
Additional Objectives
- To generate large cohorts of older adult populations and comparison cohorts of younger populations for following-up intermediate outcomes, monitoring trends, examining transitions and life events, and addressing relationships between determinants and health, well-being and health-related outcomes
- To develop a mechanism to link survey data to demographic surveillance site data
- To build linkages with other national and multi-country ageing studies
- To improve the methodologies to enhance the reliability and validity of health outcomes and determinants data
- To provide a public-access information base to engage all stakeholders, including national policy makers and health systems planners, in planning and decision-making processes about the health and well-being of older adults
SAGE Wave 0: baseline cohort from WHS 2002-04
SAGE Wave 0: A baseline cohort was created during the 2002-2004 round of the World Health Survey (WHS) and contains data on the situation of 65,964 adults aged 18 years and older, including over 20,000 persons aged 50 years and older. Nationally representative sampling frames were used to identify adults aged 18+ for interview. Oversampling of older adults (aged 50+) was included in three countries. Questionnaires and data are available by clicking on "2. Core SAGE Data and Questionnaires".
Samples of Wave 0 respondents were included in the SAGE pilot study in Ghana and also in SAGE Wave 1 in fourr of the six participating countries. A list of publications from WHS/SAGE Wave 0 is included in the link below (as .pdf).
SAGE pilot study (2005)
SAGE Pilot: The SAGE questionnaire was piloted in over 1500 respondents in three countries, Ghana, India and Tanzania in 2005. Included in the data set were 140 WHS follow-up respondents from Ghana and 76 retest interviews. Data collected included income, expenditures and transfers; work history; self-reported assessments of health linked to anchoring vignettes; risk factors; health care utilization; measured performance tests on a range of different domains of health; well-being, happiness and quality of life; and biomarkers. Questionnaires are available on this website (click on link to the right, "2. Core SAGE Data and Questionnaires").
SAGE Wave 1 (2007-10)
SAGE Wave 1: Implementation of the full SAGE was from 2007 to 2010 in six core countries over different regions of the world (China, Ghana, India, Mexico, Russian Federation and South Africa). The unique study design allowed for both follow-up and new respondents in Wave 1. The goal of the sampling design was to obtain a nationally representative cohort of persons aged 50 years and older, with a smaller cohort of persons aged 18 to 49 for comparison purposes. The target sample size was 5000 households with at least one person aged 50+ years and 1000 households with an 18 to 49 year old respondent. In the older households, all persons aged 50+ years (for example, spouses and siblings) were invited to participate. Proxy respondents were identified for respondents who were unable to respond for themselves (using the IQ Code).
In consultation with the Ministry of Health in China, China CDC and Shanghai CDC, a new sampling design was used for SAGE in China drawn from an existing national surveillance system. In India, a representative sample of six states was included, taking into consideration population size and level of development, and can be modelled to a nationally representative sample. The Russian Federation's sample was extended to the east (as compared to the Wave 0 sample) to include respondents from the "Asian" region of the country. Questionnaires are available on this website (click on link to the right, "2. Core SAGE Data and Questionnaires").
Support for SAGE Wave 1 was provided by the U.S National Institute on Aging (NIA) Division of Behavioural and Social Research (BSR) through an. Interagency Agreement. WHO provided salary support for members of the WHO SAGE team. The Governments of China and South Africa provided additional financial support for implementing the survey in their respective countries.
SAGE Wave 2 (2012)
SAGE Wave 2: Support will be provided by WHO and the U.S. NIA BSR to implement SAGE Wave 2 in 2012 in these six countries, through an Interagency Agreement. Survey instruments, methodological developments and data will be available through this website.
SAGE Wave 3 (2014)
SAGE Wave 3: WHO secured funding through the U.S. NIA BSR to implement SAGE Wave 3 in 2014 in the six core countries. Support will be provided through an Interagency Agreement with WHO and an NIH Grant R01 AG034479-01A1. After the Wave 3 round of data collection, pending financial support, future waves of SAGE to be implemented every two years.
SAGE on Wikipedia
Additional information about SAGE is available on Wikipedia at: WikiSAGE.