24. IMPROVED MEASURES AND METHODOLOGIES. In August 2003, South Africa committed to providing its population with universal access to ARVs within a few years. The Africa Centre, a Demographic Surveillance Site (DSS), monitors a high-prevalence rural South African population that will serve as a pilot site for ARV distribution, in preparation for community-wide roll-out. Universal ARV access can have profound effects on population health, which must be measured to assess success or failure of the policy, and to inform its evolving design. The Africa Centre also belongs to the INDEPTH network of DSS sites which aims to develop quantitative measures of population health. Both objectives require measures of population-level health related quality of life (HRQOL) that satisfies the three criteria of validity, reliability, and comparability. The WHO's HRQOL instrument, the World Health Survey (WHS), uses anchoring vignettes to achieve comparability, yet little is known about its validity and reliability in rural South African populations or in other populations being monitored in the INDEPTH network. We propose to assess the reliability and validity of a 7 question HRQOL excerpt from the WHS on a sample of older adults and elderly respondents from the Africa Centre's study population. ? (1) We assess convergent discriminate validity with a modified MAP-R approach using direct observation of physical and cognitive function; scales for anxiety, depression, and pain; and stylized activity lists. ? (2) We assess face/content validity using in depth interviews. ? (3) We assess test-retest reliability using repeat interviews spaced at least one week apart. ? We propose a convenient standardized research protocol, operationally integrated with routine demographic surveillance, for use by other DSS sites for reliability and validation studies of HRQOL instruments. ? ?