Background: Notwithstanding successful aging being a multidimensional construct, measuring successful aging in adults of advanced age, such as nonagenarians and centenarians, has often been challenging. First, over reliance on physical health criteria could be unrealistic, considering most of these older adults are living with multimorbidity and disability. Second, enumerating the number of criteria fulfilled may not reflect the diversity of how they attain (partial) successful aging through soliciting different resources in their daily lives. Hence, this study investigated the subphenotypes of successful aging using the data from Hong Kong Centenarian Study 2 by referencing to two models which have been adopted in previous centenarian studies. Method: Between April 2021 and September 2022, we interviewed the family caregivers of 146 community dwelling older adults aged 95 or above by phone. A structured questionnaire with items on the physical, psychological, and social well-being of the older adults was administered. Latent class analysis was used to identify the classes of successful aging based on eleven dichotomized indicators - good health, happiness, good perceived economic status, absence of dementia diagnosis, ambulation, resistance, indoor transfer, dressing, vision and hearing impairment and weekly social activities. Results: Among the 146 older adults aged between 95 to 106 (mean (SD): 97.5 (2.5); 76.0% female), 13.0% fulfilled all successful aging criteria based on caregivers’ judgments of happiness, health, and economic status, and 2.1% fulfilled all criteria based on caregivers’ observation of their physical functions and social activities. LCA identified three latent classes: Class 1 (46.6%) characterized by poor cognitive and functional health, Class 2 (37.0%) with good functional health but poor mobility, and Class 3 (16.4%) with overall good health. Class membership was unrelated to gender, age, living arrangement, and education status of the older adults. Conclusions: Although we found a relatively low occurrence of successful aging among Hong Kong adults of advanced age, possibly due to the adverse impact of COVID on their physical, psychological, and social well-being, understanding how successful aging was (partially) attained by these long-lived individuals will enable social and health care professionals to encourage late-life productive involvement, especially in the post-COVID era. (349 words)

Caregiving is often filled with pains and gains. Family caregiving for the fast-growing but vulnerable population of near-centenarians and centenarians (NCCs) may contain distinct gratifying aspects. We analyzed quantitative and qualitative data from family caregivers of community-dwelling older adults aged 95 or above in Hong Kong. Quantitative analysis of data from 143 caregivers revealed that higher age and intact hearing ability of their NCC, lack of a domestic helper, higher dependence on basic activities of daily living, higher independence on instrumental activities of daily living, and better self-rated health were related to higher scores on positive aspects of caregiving. Qualitative analysis of data from 96 caregivers identified three themes regarding these positive experiences: (i) acquiring skills to render care; (ii) fulfilling family love and obligation, and (iii) preparing for own graceful aging. Our findings elaborated the nature and mechanisms of caregiving gains against the unique backdrop of exceptional longevity of the care recipients and the Chinese cultural expectations of filial piety.