For over a decade, the World Health Organization (WHO) has been involved in engaging and assisting cities and communities all over the world in becoming “age-friendly” [1
]. The WHO proposed that policies, services, and structures in an age-friendly city, which are related to the physical and social environment, are designed to support and enable older people to “age actively”. A growing number of cities and communities worldwide are striving to better meet the needs of their older residents. The WHO Global Network for Age-Friendly Cities and Communities was established to foster the exchange of experience and mutual learning between cities and communities of different sizes worldwide [11
]. According to the WHO, the efforts of these cities and communities to become more age-friendly take place within very diverse cultural and socio-economic contexts. The common ground between these network partners is “the desire and commitment to promote healthy and active ageing and a good quality of life for their older residents”. Each member monitors its progress along the age-friendly milestones, and there is a global database of age-friendly practices, as well as a library containing member-uploaded toolkits, publications, research updates and videos [12
In 2018, the WHO signalled a number of knowledge gaps in terms of age-friendly cities and communities [12
]. The largest of these gaps is that the WHO’s age-friendly cities approach needs to strengthen its focus on multisectoral action that delivers outcomes in ways that reduce inequities. In the WHO’s own words, guidance and tools are needed to support cities and communities to make decisions around which actions are most likely to ensure these outcomes and not leave any groups behind in the process of development [12
] (p. 18). According to Buckner et al. [13
], one of the challenges for the evaluation of age-friendly city initiatives is to identify an evidence-based approach that (i) can be applied in different contexts, (ii) reflects the complexity of the initiatives, (iii) draws on sound data to make assessments of effectiveness, and (iv) presents findings clearly to a mixed audience. The researchers identified ten thematic areas where evidence was required, namely: political support; leadership and governance; financial and human resources; involvement of older people; priorities based on needs assessment; application of existing frameworks for assessing age-friendliness; provision; evidence-based interventions; coordination, collaboration and interlinkages; and monitoring and evaluation.
In short, there is a great need for monitoring, evaluating, measuring and assessing the age-friendliness of cities and communities. The Checklist of Essential Features of Age-Friendly Cities [15
] contains a large number of features which are essential to an age-friendly city, and was based on the results of the WHO Global Age-Friendly Cities project consultation in 33 cities in 22 countries. The checklist is a guide for a city’s self-assessment and a map for charting progress. This does not mean that all domains are equally relevant in all countries and cities, depending on the status quo in each country that wishes to evaluate. For conducting supportive research, one could also find inspiration in the set of core indicators published by the WHO in 2015 [16
], as well as a list of research methodologies, which can be used to investigate the age-friendliness of a city. On top of this, Fulmer et al. [17
] called for the creation of an ecosystem, where each of the age-friendly initiatives can create synergies and additional momentum as the population continues to age. Their vision for an age-friendly ecosystem encompasses the lived environment, social determinants of health, the healthcare system, and a prevention-focused public health system. At the same time, Marston and van Hoof [18
] argued about the apparent lack of consideration of technology in the existing age-friendly cities literature, which is another direction of investigation that should be included in the assessment of the age-friendliness of cities and communities, and also called for a new ecosystem. To date, despite these noble calls for new ecosystems, the lack of measurability of the age-friendliness of cities and communities is a clear weakness in moving the agenda forward.
Qualitative approaches have tried to measure and assess the age-friendliness of a city, for instance, through photoproduction [19
] and photovoice [20
] methods, or through citizen science programs of research [21
]. Various researchers have tried to come up with a more quantitative approach to measure the age-friendliness, often taking the Checklist of Essential Features of Age-Friendly Cities [15
] as a basis for their work. Luciano et al. [23
] presented a framework for the assessment of the age-appropriateness of housing through a number of metrics that detect and identify physical and non-physical features of a home environment to enable ageing in place. Their study combined data from a systematic literature review expert opinion. A total of 71 metrics were identified and divided into eight main domains to describe the framework. Their study only addressed the age-friendliness of housing, which is just one of the eight domains highlighted by the WHO. In addition, Flores et al. [24
] noted a lack of empirical research exploring the impact of age-friendly cities on older people. Therefore, they evaluated an age-friendly city by analysing its relationship with life satisfaction, taking into account the age cohort variables of older people and whether they live alone or with someone else. They conducted a two-stage study, in which 66 people participated in the qualitative analysis (focus groups) in Stage I and 203 in the quantitative analysis (survey methodology) of Stage II. The regression analysis indicates that for all age cohorts, community support and health services were significantly associated with life satisfaction. Social participation and outdoor spaces and buildings were only significantly associated with life satisfaction for older people who live together. Their research did not produce a validated questionnaire. Zaman and Thornton [25
] identified the priority indicators for age-friendly development at the local government level in Unley, South Australia. The study conducted a community perception survey to identify the important indicators, followed by a focus group consultation to identify the priority indicators based on local settings. The study identified 25 indicators as priority indicators for the City of Unley that need to be considered for the development of an age-friendly Unley. Garner and Holland [26
] described the development and validation of the Age-Friendly Environment Assessment Tool (AFEAT), assessing whether individual function and frailty impact on perceptions of environmental age-friendliness. The AFEAT was developed using the WHO Age-Friendly Environment Checklist. A total of 132 participants from the United Kingdom, aged 58–96, took part. The AFEAT, which comprises ten items (using a five-point Likert scale system), assesses individual perceptions of the environment. The AFEAT showed the need for an individual-oriented age-friendly environment tool.
All of the instruments described lack transparency of (several phases of) the development and validation process, they do not measure the age-friendliness construct as a whole (covering all eight domains as defined by the WHO) and the methodological rigour in the development process can be questioned, influencing the reliability, validity and usability of these instruments. Therefore, the aim of this study was to develop a questionnaire measuring the age-friendliness of a city or community, in line with state-of-the-art methodology described in the literature, providing full transparency and reproducibility.
The step-by-step rigorous process of development and validation resulted in a valid, psychometrically sound, comprehensive 23-item questionnaire: The Age-Friendly Cities and Communities Questionnaire (AFCCQ) which is reported in full transparency. The AFCCQ can be used to measure the age-friendliness of a city or community. To date, such a validated tool was lacking, and many cities trying to assess their age-friendliness had to resort to a qualitative or mixed methodology approach, which was often based on the Checklist of Essential Features of Age-Friendly Cities [15
]. The AFCCQ is the first validated tool that can be used for a quantitative assessment, which still allows for additional qualitative data to be shared with researchers or policy makers. The questions that were not included in the final instrument can nevertheless be used as a source of inspiration for a more in-depth survey per domain. The AFCCQ allows practitioners and researchers to capture the age-friendliness of a city or community in a numerical fashion, which helps to monitor the progress (or decline) of the age-friendliness and the potential impact of policies or social programs.
One of the main questions that needs to be resolved pertains to a cross-cultural validation. Is the current AFCCQ too Dutch in character? The Netherlands have a long-standing tradition of state-organized long-term care, with a nationwide approach to organized nursing home care and district nursing and home, social and domestic care taken care of by the municipalities. This means that for decades, the country has put great effort in improving the well-being of older citizens. This frontrunner position may impact the construct of the questionnaire and its constituting questions. In order to overcome this challenge, two international experts (Belgian nationality) were consulted who had a critical look at items that may have been too Dutch in character. This should have benefits for future cross-cultural validation procedures. Even though a rigorous translation process has been performed as a first step for future cross-cultural research, researchers who want to use the AFCCQ in their respective countries should test the cultural adaptation of the AFCCQ before using it to collect data, especially when cultures are very different from the Dutch/Western Europe culture. One of the most rigorous ways researchers can assess the cross-cultural validity of the AFCCQ is by the assessment of the measurement invariance (MI). MI assesses whether different groups respond in a similar way to a measurement instrument and its items [52
]. Only when measurement instruments have a certain level of MI can average scores on (sub)scales between different countries/cultures be compared and meaningful interpretations of results be made. One challenge with this analysis is that data from both countries are needed [52
A more user-friendly approach was presented by Sousa and Rojjanasrirat [54
], who described a seven-step guideline from translation (step 1–4) pilot testing (step 5–6) to full psychometric testing (step 7). For the use of the AFCCQ in English-speaking countries, steps 1–4 were already performed in phase 4 of this study. For non-English speaking countries, these steps should be repeated from the translated British-English version into the language of choice.
Some studies from other Western countries have addressed issues concerning national priorities. The study by Zaman and Thornton [25
] from Australia identified the priority indicators for age-friendly development at the local government level in South Australia. In their words, the WHO’s age-friendly indicators are generalised and overarching and need modification by considering local needs. Garner and Holland [26
] did similar important work from a British perspective. Their works show that a meticulous cross-cultural validation may be an important aspect in moving the AFCCQ further. At the same time, the AFCCQ was largely based on the Checklist of Essential Features of Age-Friendly Cities [15
], which is also a first indication that most of the factors constituting the questionnaire are international in their origin and applicability.
In addition, Buffel et al. [55
]—referring to the Checklist of Essential Features of Age-Friendly Cities [15
]—raised the question whether the use of a universal checklist of action items is the most adequate method to deal with the diversity of cities and heterogeneity of their populations. Creating age-friendly communities will require an adjustment of methods and instruments to highly unequal local contexts. This applies not only to the diversity between but also within cities. The question can be asked to what extent instruments such as the AFCCQ survey do justice to the diversity of older people in the city, and whether indicators and items used reflect the different needs, concerns and preferences of particular groups of older people in the city and what they consider to be important aspects of an age-friendly city. This becomes even more important given the growing number of older people with a migration background [52
], but also when we take into account existing forms of social inequality and deprivation [3
]. This applies not only to ethnic or cultural diversity, but also to other factors such as gender, age, socioeconomic position or health status, which influence what people consider important when it comes to the age-friendliness of their living environment. Garner and Holland [26
], for example, point to the relation between individual functioning and frailty and perceptions of environmental age-friendliness. When exploring the older people’s perception of their neighbourhood, Scharf et al. [56
] found that older people’s ethnic background has an important influence on people’s perceptions. This highlights the importance of paying attention to how dimensions such as gender, ethnicity, income and material deprivation, educational level, household composition and health situation impact on the perception of the age-friendliness of the city and the immediate living environment. This requires that indicators and data can be disaggregated by such dimensions. At the same time, this is also in line with the WHO’s plea [16
] to disaggregate data—from a perspective of equity—by social stratifications such as gender, age, ethnicity, socioeconomic status and neighbourhood. At the same time, these factors may influence the perceptions different groups have of the age-friendliness of their living environment. The novel AFCCQ provides a tool to move the plethora of smaller qualitative studies towards a more integrative approach of doing research, in which large-scale quantitative studies are supplemented by qualitative approaches. The AFCCQ allows for the inclusion of the abovementioned minority groups, such as people facing social inequalities, and their voices can be analysed separately in a quantitative manner. Quantitative data can help map the magnitude of social inequalities, also between subpopulations. A mixed-methods approach can help study the numerical data in more detail, for instance, when the AFCCQ domains are also studied through qualitative methodologies.
There may be a bias towards the ninth domain of financial situation (as it was taken from Hong Kong SAR (financial adequacy), and because all older people in The Netherlands enjoy a state pension under the 1956 General Old Age Pensions Act). This domain was not part of the original WHO model. Therefore, the panellists did not recognize these elements as age-friendly city indicators or a separate domain. The same can be said for the questions on technology, which correlated with other existing domains, and most questions (n
= 5) were excluded in the qualitative initial validation rounds. The experts consulted in this study may not have recognized the importance of technology as an integral part of age-friendliness [8
] yet. This may change in the future. At the same time, Marston and van Hoof [18
] called for an integrated consideration of technology, and gerontechnology in particular, in all domains of age-friendly cities, instead of technology being a separate novel domain. Future studies could pay particular attention to the role of technology in the structure of the AFCCQ. When doing evaluation studies of age-friendly cities, technology should nevertheless be addressed explicitly, both qualitatively or using an additional instrument addressing the role of gerontechnology.
Local governments and city councils can use the AFCCQ to study the age-friendliness of their respective jurisdictions. The colour scheme approach helps communicate the results of such studies to a larger audience, including older citizens. One of the strengths of the AFCCQ is that it collects data among older people themselves instead of their representatives. Policy makers may even be encouraged to move up in the sequence of colours presented by the colour scheme as a motivator through their social and urban planning policies. Policy makers may also ask for additional research in the fields with low scores. Urban planners and architects could use the outcomes of the AFCCQ as a first indication of satisfaction with aspects of the built environment. At the same time, organisations for the interests of older citizens can use the AFCCQ as well in order to provide a foundation for their actions. Researchers can apply the AFCCQ as a quick scan of a particular city, or to measure age-friendliness in a longitudinal manner, following up on a cohort in a sequence of years. After going through the procedure of cross-cultural validation, cities in various countries (in and between various countries) could be compared as well.
Some considerations regarding this study should be discussed. First, considering the representativity and size of the sample used. The representativeness of the convenient sample of community-dwelling older people (60 years and over) can be questioned as selection bias (the panel used for the study, Dutch speaking older people living in their own home). This may have led to a bias as older people with strong positive or negative experiences/emotions are more likely to participate in such panels. However, for this study, this is acceptable as the primary focus was on the psychometric validation of the AFCCQ and not an exploration of experiences of Dutch older people living in the municipality of The Hague. Regarding the sample size, there is an abundance of recommendations for the appropriate sample size to use when conducting a factor analysis. Suggested minimum sample sizes range from three to 20 times the number of variables, and absolute ranges from 100 to over 1000 participants [59
]. Even though this study met the minimum criterion of 1:3 (which means a minimum number of 135 participants), the sample size in this study is on the lower end of the advised number of participants. However, the sample size did not affect the performance of analysis, and over time, multiple studies have demonstrated that rather small sample sizes can be sufficient [60
]. One strength in this study was the lack of missing data, which maximizes the validity of the item selection during the item reduction process. Now that the AFCCQ is considered psychometrically valid, imputation of data can be performed by researchers in future studies that focus on measuring the experiences and opinions of older people regarding the age-friendliness of their respected localities. Finally, the AFCCQ provided an answer to three of the recommendations made by Buckner et al. [14
] regarding the challenges for evaluation of age-friendly city initiatives. The AFCCQ is a validated instrument which (i) can be applied in different contexts, (ii) can make assessments of the effectiveness of an intervention and (iii) presents findings clearly to a mixed audience.