GARNet’s multi-nation study of adult well being is investigating the contribution of five determinants (physical health and functional status, cognitive efficacy, social support resources, life activity, and material security) to the measurement of ageing well. The study is grounded in previous work that confirms these areas as related with ageing well (Baltes & Baltes, 1990; Johnson, 1995; Rowe & Kahn, 1997). However, the interrelationships among all five determinants have not been tested within a unified causal model framework. Specific aims of the study are to:

1. Examine the causal relationships among determinants using a full latent variable structural equations modeling to explain ageing well.
2. Investigate variation in relationships among determinants as associated with age, gender, education, and culture.
3. Examine the effect of national context on the causal determinants of ageing well.
4. Produce empirically-based index of ageing well to guide policy reviews and developments that promote ageing well systems, communities, and personal behaviors.

In each participating nation, representative samples of non-institutionalized adults, ages 50-90 years, have been developed or are nearly complete. Data are collected by trained researchers using established instruments. The five key determinants selected for their causal relationship with ageing well include the most important concerns of the study population. Multiple scales assess manifest variables for each of the ageing well determinants. The individual measurement scales have been selected based on a high degree of statistical and economic efficiency. Structural equation modeling (SEM; Byrne, 2001; Long, 1983) is applied to estimate the linear structural relationships among determinants, thus enabling a more comprehensive conceptualization and explanation of an index for ageing well. Findings will provide important information about the causal relationships among social, environmental, and behavioral/psychological determinants of ageing well in adults within countries and comparatively among the collaborating nations. The selection of determinants for ageing well and method of analysis have breadth, relevance, efficiency, validity, and flexibility.