Association between both Self-Reported and Directly Observed Physical Function and Depressive Symptoms in an US Chinese Population: Findings from the PINE Study

Purpose: The association between physical function and depressive symptoms has been widely discussed in literature. However, the heterogeneity in measuring self-reported physical function has obfuscated the applicability of research findings while limited research investigated the association between performancebased physical function and depressive symptoms. This study aims to examine the association between both self-reported and performance-based physical function and depressive symptoms. Methods: Data were derived from the Population Study of Chinese Elderly (PINE), a community-engaged, population-based epidemiological study of U.S. Chinese older adults aged 60 and above in the Greater Chicago area. Self-reported physical function was measured by Katz activities of daily living (ADL), Lawton instrumental activities of daily living (IADL), Index of Basic Physical Activities scale and Index of Mobility scale. Performance-based physical function was measured by Short Physical Performance Battery (SPPB). Depressive symptoms and depression were assessed by the Patient Health Questionnaire-9 (PHQ-9). Results: Every one point higher in ADL (OR: 1.29, 1.14-1.45), IADL (OR: 1.17, 1.13-1.22), Index of Basic Physical Activities scale (OR: 1.22, 1.19-1.26), Index of Mobility scale (OR: 1.52, 1.391.66), and SPPB (OR: 1.16, 1.12-1.19) was significantly associated with higher risk of depressive symptoms. In addition, both selfreported and performance-based physical function was significantly associated with depression. Discussion: This study initially examined the association between both self-reported and performance-based physical function and depressive symptoms and it further identified physical function impairment was not only associated with depressive symptoms, but also depression. Our study suggests that health professionals should be aware of the depressive symptoms or depression in older adults with physical function impairment.