Psychological and physical functioning difficulties associated with complex activity limitations among U.S. adults.

Background: There is limited research that assesses psychological functioning categorically as a predictor of complex activity limitations either alone or in conjunction with physical functioning.

Objectives: This paper assesses the impact of psychological and/or physical functioning difficulties as predictors of complex activity limitations among U.S. adults, using data from a national survey.

Methods: Data come from the 2006-2010 National Health Interview Survey among U.S. adults 18 or older (n = 124,337). We developed a combined physical/psychological exposure variable with six categories: 1) no/low psychological distress (LPD) and absence of physical functioning difficulties, 2) moderate psychological distress (MPD) only, 3) serious psychological distress (SPD) only, 4) physical functioning difficulty only, 5) MPD and physical functioning difficulties, and 6) SPD and physical functioning difficulties. Selected complex activity limitations include daily living, social and work limitations.

Results: Compared to adults with LPD and absence of physical functioning difficulties, the results demonstrated a clear and significant gradient of increasing risk of complex activity limitations beginning with MPD only, SPD only, physical functioning difficulty only, both MPD and physical functioning difficulties, and SPD and physical functioning difficulties.

Conclusions: The data suggest a stronger risk of complex activity limitations when increasing psychological functioning difficulties coexist with physical functioning difficulties, leading to potential interference with a person's ability to accomplish major life activities measured in this study. The sizeable contribution of psychological distress to the prevalence of basic actions difficulty implies that the mental health component of functional limitations is important in the overall assessment of health and well-being.