Bangladesh, Ghana, India, Indonesia, Kenya, South Africa, Tanzania, Viet Nam - INDEPTH WHO-SAGE (Study on global Ageing and Adult Health)

Start	End	Cycle
2006	2007	N/A

Start	End	Cycle
2006	2007	N/A

Face-to-face [f2f]

COLLECTION PROTOCOL:

This study used a modified version of the WHO SAGE survey instrument, adapting two modules from the original instrument. The INDEPTH WHO-SAGE instrument consisted of the health state description and subjective well-being and quality of life modules. The study questionnaire was developed through a consultative process between INDEPTH and WHO with the goal of integrating a feasible number of useful SAGE modules into routine surveillance update activities with minimum impact on existing HDSS procedures and maximum return on measuring health and well­-being. This instrument was translated and back-translated in eight local languages. Standardised training, interview protocols and quality assurance procedures were used across all participating sites. Centralised training was provided to principal investigators from each site, who in turn trained their respective survey teams: site­-based training averaged 4.5 days in duration across the sites. Mean interview time was 20 min.



CLEANING PROTOCOL:

Each site was responsible for cleaning their data, and the cleaned data was sent to the group coordinator. The site data were later merged into a cross­-site dataset to facilitate further cross­-site analysis. Further cleaning process of outliers were undertaken in the pooled data, and uniform indicators on various additional variables from the HDSS database were developed for all sites to ensure consistency and comparability.





ACTIONS TO MINIMISE DATA LOSS:

Following site­-level data entry and cleaning, and after a data­-sharing agreement was reached between the participating INDEPTH HDSS sites and with WHO, data were forwarded to a central location (Umeå, Sweden) for cleaning and imputation of missing data. Regular correspondence between HDSS sites improved the efficiency of the data checking and cleaning process. A working meeting held in 2008 at Umeå University, Sweden, was used to harmonise data across the sites, finalise the dataset and agree on initial outputs.



INSTRUMENT:

The abbreviated survey instrument consisted of two modules adapted from the full SAGE questionnaire: the HS and associated vignette questions plus Activities of Daily Living (ADL)-type questions (following the WHO Disability Assessment Scale version II (WHODAS-II) model), and questions on subjective well-­being as measured by the 8-item version of the WHO Quality of Life (WHOQoL) instrument.



SOFTWARE DETAILS:

Each HDSS site used their respective data entry system. Data cleaning, merging and analysis were performed in STATA Version 10.