Suitability of public use secondary data sets to study multiple activities.

PURPOSE OF THE STUDY The aims of this study were to inventory activity items within and across U.S. public use data sets, to identify gaps in represented activity domains and challenges in interpreting domains, and to assess the potential for studying multiple activity engagement among older adults using existing data. DESIGN AND METHODS We engaged in content analysis of activity measures of 5U.S. public use data sets with nationally representative samples of older adults. Data sets included the Health & Retirement Survey (HRS), Americans' Changing Lives Survey (ACL), Midlife in the United States Survey (MIDUS), the National Health Interview Survey (NHIS), and the Panel Study of Income Dynamics survey (PSID). Two waves of each data set were analyzed. RESULTS We identified 13 distinct activity domains across the 5 data sets, with substantial differences in representation of those domains among the data sets, and variance in the number and type of activity measures included in each. IMPLICATIONS Our findings indicate that although it is possible to study multiple activity engagement within existing data sets, fuller sets of activity measures need to be developed in order to evaluate the portfolio of activities older adults engage in and the relationship of these portfolios to health and wellness outcomes. Importantly, clearer conceptual models of activity broadly conceived are required to guide this work.