BACKGROUND

Half a century after the inception of the term "successful aging (SA)," a consensus definition has not emerged. The current study aims to provide a comprehensive snapshot of operational definitions of SA.

METHODS

A systematic review across MedLine, PsycInfo, CINAHL, EMBASE, and ISI Web of Knowledge of quantitative operational definitions of SA was conducted.

RESULTS

Of the 105 operational definitions, across 84 included studies using unique models, 92.4% (97) included physiological constructs (e.g. physical functioning), 49.5% (52) engagement constructs (e.g. involvement in voluntary work), 48.6% (51) well-being constructs (e.g. life satisfaction), 25.7% (27) personal resources (e.g. resilience), and 5.7% (6) extrinsic factors (e.g. finances). Thirty-four definitions consisted of a single construct, 28 of two constructs, 27 of three constructs, 13 of four constructs, and two of five constructs. The operational definitions utilized in the included studies identify between <1% and >90% of study participants as successfully aging.

CONCLUSIONS

The heterogeneity of these results strongly suggests the multidimensionality of SA and the difficulty in categorizing usual versus successful aging. Although the majority of operationalizations reveal a biomedical focus, studies increasingly use psychosocial and lay components. Lack of consistency in the definition of SA is a fundamental weakness of SA research.