The population of oldest-old (those aged ≥80 years) is rapidly growing. Worldwide, the number of oldest-old people is predicted to increase by more than three times between 2015 and 2050, from 126.5 million to 446.6 million [
1]. In Japan, the proportion of the oldest-old in the total population is estimated to rise from 8.7% in 2018 to 15.8% in 2050 [
2]. By 2050, one in seven Japanese people will be aged 80 years or older. With the increasing length of life and rising older population, there are concerns about significant increases in medical and long-term care costs in Japan [
3]. Although improved life expectancy is a positive outcome, it gives rise to a new issue of how to ensure health and well-being among the oldest-old population.
Older people frequently experience aging-related changes and losses, such as declines in health and functioning, increased chronic illnesses and comorbidities, reduced independence, death of spouse/friends, and loss of social networks [
4,
5]. Many previous studies [
6‐
8] focused on preventing or delaying these changes and losses in older age. However, the oldest-old people have difficulty avoiding the impact of problems that increase with age, and adaptation to such changes and losses is critically important for well-being in later life [
9‐
11]. In oldest-old age, prevention of aging-related changes or losses and adaptation to these aspects in their later life are essential to promoting health and well-being.
Resilience is a broad construct that involves concepts of adaptation. Although consensus around the definition of resilience is lacking, many authors have described resilience as an individual characteristic that allows people to cope with stress and adapt to threats [
12,
13], or a dynamic process of adaptation [
5,
14]. This concept includes multiple resources for adaptation, such as psychological resources (e.g., self-esteem, coping ability), health resources (e.g., health promotion, physical activity), and sociocultural resources (e.g., social networks, social capital). Resilience among older people has been related to health outcomes such as survival [
15‐
17], independence [
18], self-rated health [
19], and depression [
20,
21]. A review focused on resilience in oldest-old age [
22] suggested that the conceptualization of resilience is the process of interaction between surrounding adversity, resource availability and mobilization, and positive outcomes. That review also found that to enable good adaptation in oldest-old age, it is important to focus on resilience, especially multiple individual resources such as psychosocial resources, valued activities, life experience, and spirituality. These findings suggest that resilience is an important concept in adapting to aging-related changes and losses and promoting health and well-being among the oldest-old population. However, no scale for evaluating resilience among the oldest-old is currently available. A search of the literature clarified that although measures exist for assessing psychological resilience in adults [
12,
13,
23], along with broader resilience scales for adults [
24] and older adults [
25,
26], there is no concept or scale focused on adaptation to aging-related changes and losses that targets oldest-old people. It has been suggested that the resilience of oldest-old people differs from that of younger people in terms of constructs, correlates, and consequences [
22,
27]. First, in terms of constructs, the resilience of the younger generation is characterized by personal characteristics, traits, and skills used to confront threats, whereas the resilience of the oldest-old old includes their life experiences, wisdom, and meaning in life. Second, in terms of correlates, the resilience of the younger generation includes resilience against age-neutral adversities, such as depression, anxiety, and traumatic experiences, whereas the resilience of oldest-old age includes resilience against age-specific stresses, such as function loss, physical health challenges, and diminished social networks due to aging. Third, in terms of consequences, the resilience of the younger generation focuses on the goals of recovery from illness and health promotion, while the resilience of the oldest-old focuses on maintaining independence and competency, such as comfort in daily life and a sense of one’s own value. Therefore, there is a gap in terms of a tool to assess resilience among this population.
This study aimed to develop a framework for a resilience scale for oldest-old age (RSO), and present findings on the psychometric properties of the scale. The overarching goal was to promote health and well-being among oldest-old people.