There are two main approaches to dealing with the concept of QoL. It can be seen as a single, unified entity [
39,
40], or alternatively as a collection of separate domains [
41,
42,
43]. In particular, considering the assessment of QoL for older people, various studies proposed a different set of domains. Older individuals have generally acknowledged the significance of social relationships, family relationships, health, comfort, safety, leisure activities, psychological well-being, financial security, and independence to their overall quality of life [
44,
45]. For example, Murphy, O Shea, and Cooney [
46] identified four QoL domains: care environment and ethos of care, personal identity, connectivity to family and community, and activities [
47]. Other studies suggested that factors like good health greatly influenced the QoL of older people, a reasonable level of independence and autonomy, the presence of a social network and social support, the capacity to participate in meaningful activities, a stable financial status, and living in a welcoming place [
48,
49]. In other studies Health, independence, family, activities and leisure, social network and connections, and finances were the most relevant QoL domains among older people, however, the order of the domains varied among countries and samples [
50,
51,
52,
53]. In their study of QoL for older people with care needs Kuboshima and McIntosh [
54] identified independence and control, privacy, personal identity, meaningful activities, relationships, and quality of care as relevant themes. Through this review, the aspects (domains) of QoL of older people that will be studied further in this study would are: autonomy, activities, social relations, leisure, and health (
Table 2). These were derived from the literature adopting a cluster analysis [
55]where similar themes were grouped into distinct domains thereby identifying patterns and relationships in the data.
3.1. Autonomy
Autonomy as a domain of QoL is widely studied in the literature [
57,
58,
59,
60]. It has been proposed that autonomy has a physical as well as a psychological dimension [
61]. The psychological dimension relates to control over one’s environment and the capacity to regulate and make decisions about one’s life, whereas the physical dimension refers to mobility and low levels of physical limits, including usage of the environment [
59]. However, within these broad dimensions, the definition of autonomy is still contested. For example, autonomy is defined as ‘the perceived ability to control, cope with and make personal decisions about how one lives on a day-to-day basis, according to one’s own rules and preferences’ [
3]. Various phrases have been used to define the term such as ‘control’, ‘agency’, ‘mastery’, ‘self-management’, ‘self-determination’, ‘independence, and ‘choice’ [
58,
62,
63]. The definition by Knight et al. [
64] may best define autonomy from the perspective of the environment. They define autonomy as ‘having a sense of competence in managing one’s environment, an ability to control external activities and to select or develop contexts suitable to one’s needs’. Likewise, Lee et al. [
65] define autonomy as ‘Mastery over environment’. These definitions are based on ecological models, namely person-environment fit, denoting the interaction between person and environment and, the concept of autonomy is studied in association with terms mobility, activity, health (person), and environmental barriers (environment).
The environment may pose serious challenges to older people’s mobility and therefore autonomy if inappropriately designed. Outdoor independence declines as perceived environmental barriers increase [
60] and the reduction in older adult’s autonomy in participating in outdoor activities is accelerated by perceived environmental constraints to outdoor mobility [
59]. The most frequent environmental elements that have a negative impact on older people’s autonomy include narrow, uneven, cracked, steep sidewalks [
35,
60,
66,
67], high curbs, curb ramps [
35,
60,
66,
68], puddles and poor drainage [
35,
66], problems with pedestrian crossings [
67], inappropriate signage or lack of signs [
60,
69], lack of resting places [
60,
67,
70], poor lighting of sidewalks [
35,
60], lack of public toilets [
60,
67,
71], and distance to important destinations [
60,
72,
73]. Other evidences support the association between being active and autonomy [
60,
67,
74,
75]. Limited mobility is typically associated with a diminished sense of autonomy [
59,
76]. Health is another factor that can adversely affect autonomy and people’s poor health is an underlying cause of physical and psychological dependence [
77], not to mention the barrier to successful old age.
3.2. Meaningful Activities
There is a close relation between the study of QoL and active ageing; in fact, high QoL is an outcome of active ageing. Defined and promoted by the World Health Organization (WHO) [
3], active ageing is “the process of optimizing opportunities for health, participation, and security in order to enhance QoL as people age”. According to this definition, active ageing is composed of two vital components, a positive attitude about ageing [
78,
79] and an encouragement to participate in social, economic, cultural, and spiritual activities [
80]. These two components are intertwined, and research has linked perceived environmental barriers outside to physical inactivity and a reduction in participation in community events [
59,
81]. Being inactive has many physical, functional, and psychological consequences that can conversely affect the QoL. Physical inactivity is a substantial risk factor for cardiovascular disease, type 2 diabetes, obesity, some cancers, poor bone health, various aspects of mental health, and overall mortality [
82,
83].
The built environment has a substantial role in promoting or hindering physical activities among older people. Older adults who live in an age-friendly environments are more likely to be active outdoors [
60,
84,
85]. However, despite various incentives and policies [
3], most older people in developed countries do not engage in enough physical activity. For example, in the UK, just 13% of those aged 75 and over and 25% of those aged 65 to 74 engage in the basic levels of physical activity recommended for adults (150 minutes of moderate-intensity activity or 75 minutes of vigorous activity or a combination of both per week) [
83,
86]. The most favoured activities reported by older people [
57,
87], other than physical exercise, were, reading, gardening, watching television, strolling, caring for the home, shopping, knitting, traveling, visiting relatives, and cooking. Various environmental factors can promote physical activities among older people. A recent review concluded that safe, walkable, and visually pleasant neighbourhoods with access to general and specialized destinations and services increased older people’s physical activity engagement favourably [
88]. Living in the city centre and walking and cycling-friendly built environments positively impact physical activities [
60,
89,
90]. Moreover, physical activities have positive outcomes for older people, including an improved sense of value, better sleep, stress reduction, and better social relationships [
83,
91,
92].
3.3. Facilitating Social Relationships
Social relationships have physical, social, and psychological implications for the ageing society. They impact physical and mental health and are closely related to other aspects of QoL, such as autonomy, physical activities, and health. While good social relations can have a positive effect, social isolation can be detrimental to the physical and mental health and restrict the QoL of older people. “Social isolation” is defined as having a narrow network of kin and non-kin ties and hence little or occasional contact with others“ [
93]. Social isolation and loneliness are common in older people. For example, in United States of America, Europe, Latin America, and China, 20-34 percent of older adults experience loneliness [
93]. There is compelling evidence that social isolation and loneliness increase the chances of physical health diseases like cardiovascular disease and stroke, as well as mental health conditions including cognitive decline, dementia, depression, anxiety, suicidal thoughts, and actual suicide among older persons [
94,
95,
96,
97]. In studying the social relationships of older people, it is important to consider both social and physical environments and focus on those factors that hinder or facilitate social relationships, which could improve social cohesion, place attachment, and QoL among older people.
Social relationships have physical, social, and psychological implications for the ageing society. They impact physical and mental health and are closely related to other aspects of QoL, such as autonomy, physical activities, and health. While good social relations can have a positive effect, social isolation can be detrimental to the physical and mental health and restrict the QoL of older people. “Social isolation” is defined as having a narrow network of kin and non-kin ties and hence little or occasional contact with others“ [
93]. Social isolation and loneliness are common in older people. For example, in United States of America, Europe, Latin America, and China, 20-34 percent of older adults experience loneliness [
93]. There is compelling evidence that social isolation and loneliness increase the chances of physical health diseases like cardiovascular disease and stroke, as well as mental health conditions including cognitive decline, dementia, depression, anxiety, suicidal thoughts, and actual suicide among older persons [
94,
95,
96,
97]. In studying the social relationships of older people, it is important to consider both social and physical environments and focus on those factors that hinder or facilitate social relationships, which could improve social cohesion, place attachment, and QoL among older people.
Similarly, it is well established that aspects of the built environment greatly impact older people’s social ties. Evidence shows that senior women’s social engagement and psychological health can both benefit from public spaces [
98]. One study suggests that urban density does not affect the sense of loneliness, while satisfaction with the living environment, accessibility to major roads, and mobility can enhance social relations [
99]. Another study suggests that feelings of loneliness are inversely correlated with contentment with neighbourhood facilities and services and perceptions of safety [
100]. Additionally, studies suggest that green communal spaces and allotment gardens contribute to social inclusion and a sense of community [
101,
102]. These studies suggest that outdoor communal spaces, contribute to satisfaction with living environments and self-worth and that the ability to congregate, either through denser living arrangement or though access to transportation benefit QoL.
3.4. Accommodating Leisure Activities
Leisure activities are part of physical activities in our daily life, potentially improving physical and mental well-being and enhancing QoL [
103]. The development of positive emotions and identities, the satisfaction of crucial life needs, the preservation of our spiritual balance, the improvement of our social and cultural connections with others, the capacity to cope with and transcend challenging life situations, and the promotion of positive human development throughout our lifetimes are just a few of the meanings derived from leisure activities [
104,
105,
106]. Leisure and recreational activities are deemed to be salient in people’s lives. In a study in the US, the vast majority of American adults (83 percent) believe that parks, trails, and other open spaces are necessary for people’s physical and mental well-being [
107,
108]. Leisure activities enable the setting or stage for emerging meanings that advance people’s QoL [
105].
Many personal factors promote the engagement and participation of older people in leisure activities. Being female, living with a partner, having a higher number of social contacts, having higher socioeconomic status, and psychological factors such as higher levels of self-efficacy are among the significant factors that predicate participation in recreational activities [
109]. However, the reduction in engagement associated with growing age is one of its primary features in later life for reduced QoL [
110,
111]. Outdoor social activities and the variety of leisure activities were greatly impacted by one’s level of fitness and health, as well as by the accessibility of transportation. Sports activities were mostly linked with men, those with higher education, those who drove vehicles, and those in good physical shape [
112]. For older adults, higher socioeconomic status, widowhood, a broader network of friends, volunteering, transportation options, and fewer depressive symptoms all had a role in the degree of social leisure involvement [
109]. It is generally well-established that leisure activities are linked to better physical and mental health outcomes [
90].
Less attention has been paid to environments that might either facilitate or hinder the participation of older persons in leisure activities [
109]. As mobility in its various forms is a prerequisite to being active, transportation possibilities are repeatedly mentioned as the factors that have a positive role in leisure activities [
112,
113]. Moreover, living in deprived neighbourhoods is associated with less frequency of leisure activities [
111]. Leisure activities and satisfaction have been shown to be positively related to residential density, urban greenness, and local amenities [
90,
114,
115]. Likewise, people are more likely to report less leisure walking if they live in areas with a low diversity of land use mix [
116]. Access to gardens, grass spaces, walking routes, water features, wildlife, amenities, dog-related facilities, and off-leash dog parks were all found to be connected to promoting walking in public open spaces [
117].
3.5. Fostering Good Health
Health in old age is linked to most domains of QoL. For example, meaningful activities, having good social relations, and leisure can all lead to better physical and mental health. Likewise, being active in later life is related to greater independence and autonomy [
118]. There is a widespread agreement that health in old age cannot be defined effectively as the absence of disease, instead health is viewed as a multifaceted construct. The reduction in functional capacity and the increase in the number of functional limitations are a well-studied aspects of the ageing process [
119]. Along with the decline in functional capacity, being inactive can pose serious physical and mental health risks. Up to 20 percent of dementia risk in the population may be attributed to physical inactivity [
7]. However, the proportion of the population achieving the required levels decreases with age. Studies of SAGE and WHO, World Health Survey data, reveal that around one-third of persons aged 70-79 and one-half of those aged 80 and beyond fail to satisfy basic WHO standards for physical activity in old age [
7].
The environment has significant implications for the QoL of older people. Following the ecological theory of ageing [
120], there is a direct relationship between individuals’ competence and the demands of the environment. In this context, people with lesser competency are more attentive to the needs of the environment than people with higher competence. Neighbourhood surroundings can help older people’s health in two ways. One way is to provide opportunities for active participation. Another approach may be to provide areas where individuals can gather with others and appreciate nature [
85]. Thus, being healthy is an outcome of mobility in activities that lead to independence and autonomy. Outdoor mobility is a crucial subject that has the potential to stimulate or inhibit autonomy and hence to compel or avoid impairment [
121]. Walkable green streets, access to public spaces, and park density may contribute to older adults’ health and health-related QoL (HRQOL) [
122,
123,
124]. Other factors that promote health among older people include increased perceived diversity, safety, aesthetics, accessibility of neighbourhood amenities, leisure, social interaction, and less reported noise [
122,
123,
125,
126]. In addition, one study showed a solid correlation between lower depressive symptoms and the amount of urban greenery and commercial space within a 500-m buffer [
127]. Overall, better health is associated with higher QoL and life satisfaction [
57,
128] and the physical environment can positively contribute to better health.