A matrix was offered which included an outline containing the year, population, country, research method, and aspects of active aging concept (Appendix 1 and 2). The majority of the articles have been conducted during 2002 to 2018 and only a few have recently been published (eg, Ko & Yeung (2018)). Also, most of the articles were conducted in the U.S., and most of the quantitative studies used either surveys or second data analysis and follow-up methods. However, most frequently, quantitative studies focused on social engagement, physical, and mental well-being and built environment, while qualitative papers emphasized life satisfaction. Figure 2 demonstrates the flow chart adapted from preferred reporting items [27, 118].
Thematic analysis
Different aspects of active aging based on qualitative content analysis were coded and categorized during the process of data analysis, the results of which are shown in Table 2 in the form of codes, subthemes, and themes. Different aspects have also been presented and summarized in a matrix, with 15 subthemes and 5 themes called 5P model: (1) person (personal status), (2) process, (3) place (built environment), (4) policymaking, (5) and prime (Fig. 3).
Themes
Person
One of the core themes is “person” that can be divided into 2 subthemes: personal characteristics and behavioral attitude. Most studies conducted on active aging provided an analysis of the effects of personal aspect, including health, age, shared genetic attributes, educational level, socioeconomic status, ethnicity, self-efficacy, and exercise history [23]. In addition, many studies included diet and lifestyle factors which are related to the person’s behavior such as adoption of a balanced diet and food restrictions [38]. These restrictive diets and eating habits appear to be aimed for a balance between the imposition of the aging physique and the limitations due to disease and sickness. Therefore, to maintain active aging, a healthy diet should be considered as a major component for older people to provide them with strong levels of health and well-being, which in turn help them experience growth and maturity [38]. Another component associated with the behavior aspect that can maintain active aging is the attitude towards these behaviors, because it can be modified at any point leading to a considerable increase in active aging [38]. Therefore, several studies found that those elderly who have never smoked or drank enjoyed a considerably better active aging compared to those with such habits [38]. Evidence also suggests that physical activity is a significant factor in active aging [23, 38].
Prime
The ecological model described by Stocks in the context of healthy environments is a broad framework which takes into account the physical environment and the psychosocial environment [119]. The proposed ecological model demonstrates the functional relationships between the aging person and the micro, meso, and macro system levels of the environment, along with the unstable equilibrium between environment and individual competence in very old age [118].
In this narrative review, “prime” is a reflection of health and components within the concept of health; namely, physical, mental, and social health. According to WHO definition, health is a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity [120]. This shows that several factors should be considered to grasp the idea of health, including biological, social, and psychological aspects.
The environment includes the natural and the man-made components alongside each other, which significantly affects the health state of an older person. Strong evidence supports the fact that living in an environment of low quality results in decreased physical health, associated with high prevalence of degenerative disease, incidence of falls, cardiovascular mortality, and reductions in longevity and increased disability, poor quality of life, and poor self-reported health [23, 42, 53, 54, 57, 67, 77, 87, 88]. Several mental health issues were also examined in the literature, including depression, anxiety, anger, psychological well-being, and cognitive functioning (mental processing, speed, and working memory) [23, 53, 57, 65, 79, 87, 88, 93, 115]. Social health [98] and well-being literature, on the other hand, focuses on the quality of interpersonal relationships between the members of a society and the amount of their involvement in their community. Several studies conducted on social well-being were assessed, and as a result of which it was found that to propose the level of social well-being for a group of people, their performance must be studied in the following areas: (1) family, (2) work, (3) community involvement, and (4) social life or sociability of individuals (eg, friendships) [117].
However, community health and psychological health are the results of the efforts contributed by epidemiologists and environmental psychologists, which include the sense of community identity, community empowerment, social capital, and culture [116].
Process
“Process” as the core ecological theme in active aging includes 3 subthemes: social, economic, and cultural environments, which are significantly important in the lives of an aging older person, as these can be barriers for life activities and may have health outcomes [23]. In this study, the literature search focused on those activities in the active aging policy framework by WHO that outlined key items as physical, social, cultural, civic, spiritual, and economic activities [2]. Many researchers have decided to study the role of social environement, which includes proximate social networks, social capital (norms of reciprocity and trust), and incidental social interactions [23]. Also, important components of social environement that affect an increased active aging include different social contacts, increased social involvement, wide social network, living children, ethnic homogenity, increased sense of neighborliness, increased literacy, increased social and economic status, increased workforce involvement, time spent with friends, and an age-specific community [1, 7, 23, 31, 32, 35, 40,41,42, 44, 51,52,53,54, 58, 60, 63, 65, 69, 70, 72, 79, 80, 83, 87, 93, 100,101,102,103,104,105,106, 121].
There are some specific characteristics of the social environment that requires the elderly to meet specific demands leading to suboptimal active aging. These may include family’s financial problems, a partner with health problems, unrealistic expectations of the person from their friends and families, and weak social and economic status of the area which is recognized as economic environment [1, 7, 23, 31, 40, 41, 70, 78, 86]. In addition, there is also the cultural environment which consists of religious activity, cultural events/rituals/social activity, and sense of place [42, 53, 54, 57, 80, 85, 87]. In this study, based on strong evidence, it was found that a powerful and supportive social network enhances the well-being and longevity of the elderly in the society. However, the composition of this supportive network may differ from one society/person to another [23]. The extent of poverty is also among the commonly mentioned factors that affects the activity involvement of the people. Yet, several studies maintained that lower social and economic status of an area is linked to the physical activity of individuals, which may be the case due to this group’s need for work and transportation. In fact, active aging includes social, cultural, civic, spiritual, and economic elements, which potentially contribute to health and well-being in later life [2, 23].
Place
The theme of “place” consists of land use, physical form, housing themes, access, public space quality, and city image/townscape. There are several reported environmental characteristics that enhance the elderly’s well-being, including the proximity to and density of public open space and recreational facilities, high-quality facilities (social and leisure facilities, age-appropriate facilities), peacefulness, cleanliness, safety of public areas and street crossings, frequent rubbish collection, access to health services, transport availability, closeness to shops and places for walking, living in a retirement village, living in a hillside area, living in an area with high rainfall and living in a residential environment [23], and lack of littering/vandalism/decay [40].
Furthermore, those studies that have addressed the importance of place in the discussion of active aging were identified, which included the following factors: measures of land use characteristics (area deprivation or poverty, and neighborhood degradation) [23, 33, 41, 42, 44,45,46,47,48,49,50,51]; physical form (neighborhood degradation, accessibility to services and facilities, accessibility of public greenspace, walkability, or pedestrian friendliness) [3, 7, 23, 31, 33, 41, 42, 48, 49, 51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79, 81, 82, 122]; physical form as security of perceived crime and antisocial behavior; safety of traffic conditions [7, 31, 33, 41, 42, 44, 48, 53,54,55, 60, 62, 63, 68, 75, 79, 83,84,85,86,87, 123]; quality of public space [23] as aesthetics and architecture, landscape (lighting and furniture) [33, 53,54,55,56,57, 64, 75, 85, 87,88,89,90], pedestrian-friendly features and availability of benches/sitting facilities [40]; trip hazards at home and neighborhood; home and environmental adaptations, climate and topography [23]; and favorable physical attributes such as trees and green areas which provide a sense of well-being and support resilience. Other positive factors were favorable street design, access to public transportation system, and several retail outlets which could be a motivating factor for more community involvement and physical activity [10, 33, 53,54,55, 57, 64, 75, 85, 87,88,89,90]. Identifying such diverse types of environments for careful analysis helps to assess homes or care centers and typology of land use, including rural and urban uses, categorization according to population density, defining areas based on time/distance, and defining a neighborhood by its members. Interestingly, in this review, it was found that most studies provided researcher-based definitions of a place as the built environment [23, 41, 47,48,49, 56, 68, 70, 77, 91,92,93,94,95,96,97].
Policymaking
Studying environments in the previous body of literature also included government-defined administrative areas as census tracts or postal codes [23], which focused on the key concepts of tolerance, fairness, social justice, and good governance (effective collaboration and political commitment to the elder performance orientation, openness, transparency, and integrity governance, and equity/inclusiveness) [61, 70, 73, 91, 107,108,109,110,111,112, 114, 124, 125] as necessary elements in sustainable development of urban planning. While physical and social environments are both important aspects to ensure the elderly’s health state, favorable governance and planning of the environment are of significant importance in building an age-appropriate community. To this end, several models have been proposed to address this important issue. However, the results showed that consensus planning using meaningful community involvement is significantly needed for these complex areas. Moreover, collaborative governance efforts with different players and sectors through the stages of building a community are also of great importance, as the public was considered as a body to consult with rather than active members in developing knowledge, space, or governance centers [126].
Study quality
A considerable number of the included articles clearly provided objectives and methods compatible with the aims of their research. Comprehensive details of the studies’ quality are provided in appendices 1 and 2. In brief, since many of these articles applied a self-selected sampling, their results were enormously influenced by selection and information bias, which could affect their internal validity and, perhaps, the quality of quantitative studies, and to a lesser extent, qualitative studies. Furthermore, there were some observational studies which could not be considered as transferable and generalizable due to their small sample size and the methods used. This review was based on a qualitative process considering different aspects, which can provide different requirements for international scales, different types, etc. An iterative review, including all relevant literature to derive themes to accommodate smaller qualitative pieces of work that may have specific implications to international communities, small or large, with diverse societal, cultural, and religious belief systems, was conducted.
