Background: Globally, ageing impacts all countries, with a majority of older persons residing in lower- and
middle-income countries now and into the future. An understanding of the health and well-being of these
ageing populations is important for policy and planning; however, research on ageing and adult health that
informs policy predominantly comes from higher-income countries. A collaboration between the WHO Study
on global AGEing and adult health (SAGE) and International Network for the Demographic Evaluation of
Populations and Their Health in developing countries (INDEPTH), with support from the US National
Institute on Aging (NIA) and the Swedish Council for Working Life and Social Research (FAS), has resulted
in valuable health, disability and well-being information through a first wave of data collection in 20062007
from field sites in South Africa, Tanzania, Kenya, Ghana, Viet Nam, Bangladesh, Indonesia and India.
Objective: To provide an overview of the demographic and health characteristics of participating countries,
describe the research collaboration and introduce the first dataset and outputs.
Methods: Data from two SAGE survey modules implemented in eight Health and Demographic Surveillance
Systems (HDSS) were merged with core HDSS data to produce a summary dataset for the site-specific and
cross-site analyses described in this supplement. Each participating HDSS site used standardised training
materials and survey instruments. Face-to-face interviews were conducted. Ethical clearance was obtained
from WHO and the local ethical authority for each participating HDSS site.
Results: People aged 50 years and over in the eight participating countries represent over 15% of the current
global older population, and is projected to reach 23% by 2030. The Asian HDSS sites have a larger proportion of burden of disease from non-communicable diseases and injuries relative to their African
counterparts. A pooled sample of over 46,000 persons aged 50 and over from these eight HDSS sites was
produced. The SAGE modules resulted in self-reported health, health status, functioning (from the WHO
Disability Assessment Scale (WHODAS-II)) and well-being (from the WHO Quality of Life instrument
(WHOQoL) variables). The HDSS databases contributed age, sex, marital status, education, socio-economic
status and household size variables.
Conclusion: The INDEPTH WHOSAGE collaboration demonstrates the value and future possibilities for
this type of research in informing policy and planning for a number of countries. This INDEPTH WHO
SAGE dataset will be placed in the public domain together with this open-access supplement and will be
available through the GHA website (www.globalhealthaction.net) and other repositories. An improved
dataset is being developed containing supplementary HDSS variables and vignette-adjusted health variables.
This living collaboration is now preparing for a next wave of data collection.