“Successful Aging”—Where Next?

The idea of “successful aging” has been the subject of research for a broad range of academic disciplines for more than 3 decades. Early mention of “successful aging” can be found in the work of social scientists in the United States during the 1960s and 1970s. 1–6 During the 1980s and 1990s, psychologists and behavioral scientists addressed successful aging. 7–11 Over the last 2 decades, physicians and health services researchers have contributed to theories of successful aging. 12–19 In recent years, this concept has gained increased attention, likely because of a combination of demographic trends and social forces. Baby boomers—those born between 1946 and 1965—face the prospect of surviving to very old age, and those who have already reached the age of 65 have a life expectancy of an additional 16 to 20 years. 20 Furthermore, analyses using longitudinal data suggest that, in addition to living longer, people are healthier and more active than before and that rates of disability and institutionalization will continue to fall in the future. 21–24 Finally, older adults are more highly educated than previous generations and are interested in health-related matters. 25 Because of this combination of circumstances, healthcare providers may find their patients seeking information about how to age successfully. Some patients may want to apply scientific findings to their own situations to maximize their personal likelihood of aging successfully. We therefore conducted a review of published literature that has attempted to define successful aging and the factors that might predict success. Articles were identified from the following sources: (1) MEDLINE search (using the key terms “successful aging,” “normal aging,” “theories of aging,” “centenarians”); (2) psycINFO search (using the same key terms as in (1)); (3) on-line card catalog search (using the key term “aging”) of the University of Washington libraries, which contain over 1.9 million book titles; (4) recommendations from local reviewers of the manuscript; and (5) reference lists of all articles and books found by the procedures just described. No exclusions were made for year of publication. Studies were excluded if they used a definition of successful aging that had already been identified, if they focused on a related concept (e.g., healthy aging, effective aging, elite aging) but made no mention of the term “successful aging,” or if they were not published in English. We were not seeking to provide a comprehensive literature review on lifestyle factors that promote healthy aging. Neither did we intend to propose a definition of successful aging or argue for the validity of the concept of successful aging—as a stand-alone construct or in comparison with other related, but nonetheless distinct, concepts such as healthy aging. Rather, our intent was simply to identify and present in a highly summarized format the many and varying definitions of successful aging that have been put forth in the literature over the past 30 to 40 years. We intend this summary to be a succinct reference for clinicians who care for aging adults and researchers engaged in the study of aging. In addition, we offer a rationale for exploring the public’s definition(s) of successful aging; we also suggest questions and design considerations for those seeking to pursue further work related to this concept.