Background
Housing in old age is a burning issue throughout the world, and there is a great need for research on the home and health situation in different groups of the ageing population. Overall, as a result of policy changes in the Western world there has been a shift from institutional care to home health services, and the majority of people remains in their ordinary homes well into old age [
1,
2]. In Sweden, the majority of older people live in the same types of ordinary housing as the younger population [
2]. Also among very old people, only a small percentage resides in special housing. Against this background, the public debate raises concerns about how to supply the optimal type of housing to senior citizens with different functional statuses and different needs [
3]. A first step would be to refine the discussion based on research comparing the home and health situations of different sub-groups of the ageing population rather than considering all older people as a homogeneous collective. Accordingly, there is a need for more nuanced and sub-group based housing policies and practices to meet the needs on an individual level, but the current scientific evidence is insufficient to come up with effective solutions regarding the home and health situation along the ageing process.
Most studies on ageing cover a multitude of information on the ageing person, but empirical ageing research with a balanced view on person and environment remains rare. Within the gerontology literature there is consensus that both personal and environmental resources contribute to healthy ageing. Nevertheless, the contribution of key elements of the immediate environment, such as the home, remains overlooked. As put forward by Wahl et. al., [
4], there is a need for a deepened understanding of the interchange between people and their environments. During the last decade, our research has influenced the international knowledge frontier regarding home and health dynamics and increased the awareness of the complexity of housing related to ageing (see e.g., [
5]). Recently, synthesizing 35 original articles from the ENABLE-AGE project we highlighted that in very old age, the interplay between aspects of perceived and objective housing and aspects of health could influence residential decision-making (), independence in daily activities and social participation [
6]. As yet, this knowledge is based on longitudinal research on very old, single-living people in five European countries [
7], and thus there is also a need to study other sub-groups in the ageing population.
Studies on home and health dynamics often relate to Lawton and Nahemow’s [
8] ecological theory of ageing (ETA) and subsequent elaborations such as those presented by Scheidt and Norris-Baker [
9]. According to the ETA, the interacting combination of an individual’s competence and the demands of the environment (person-environment fit; P-E-fit) are important for an individual’s adaptive behavior and level of functioning. Moreover, the docility hypothesis suggested that the lower an individual’s competence, the greater the impact of the environment on his or her ability to compensate for the negative consequences of environmental press. Most important, the environment should be understood as a dynamic and context-bound phenomenon which encompasses aspects of objective as well as perceived character [
10].
It has long been argued that there is a need for a broader diversity of research regarding home environments including different sub-groups of the ageing population with different levels of competencies and life experiences [
1]. In response to this quest, in a recent study on people aged 67–70 living in ordinary housing in south Sweden [
10], we showed that the majority are in good health and have few functional limitations. Women have more functional limitations and report more symptoms than men. While environmental barriers do exist in all dwellings (in particular in kitchens and hygiene rooms), on an overall level they are more common in multi-family than in single-family dwellings. Based on analyses made for a recent Swedish governmental commission [
3] we also know that the environmental barriers in multi-family dwellings are of a somewhat different character than those in single-family dwellings, and that there are significant differences between housing types depending on building period.
In order to expose contrasts and shed new light on home and health dynamics in different sub-groups of the ageing population, the aim of the present descriptive study was to compare a younger old cohort to a very old cohort living in ordinary housing in Sweden.
Discussion
With the present study, differences in the home and health situation between two sub-groups of the ageing population in southern Sweden were identified. While the two cohorts were recruited based on age criteria and thus represent a very old and a younger old cohort, respectively, it should be kept in mind that they differed also in other respects that deserve further research attention. Still, since the differences in health were in line with previous research based on age differences [
25,
29], the results regarding objective and perceived aspects of home indicate intriguing differences that represent new insights that deserve further research attention.
Although the very old cohort lived in dwellings with fewer environmental barriers, in particular indoors, they still had more accessibility problems due to having more functional limitations. Therefore, even if people seem to seek “better housing” as they age, they do not sufficiently compensate for the increasing complexity of functional limitations coming with advanced age [
29]. Accordingly, foresighted planning as well as the availability of ordinary housing without the types of environmental barriers that typically generate accessibility problems for very old people may be crucial if one can stay in ordinary housing or have to move to special housing [
3,
30,
31].
Further, previous results based on data on the very old cohort have shown that environmental barriers are more prevalent in multi-dwelling blocks compared to one-family housing, and that about 80% of the environmental barriers are related to the indoor environment or entrances [
12]. Taking into account that over 83% of the very old cohort lived in multi-dwelling blocks, the ageing population places great demands on public and private providers of such housing to reduce the most common and problematic environmental barriers and thereby reduce the occurrence of the accessibility problems. However, increasing the knowledge further on such details of the housing environment is a more complex matter than might be expected as differences in terms of specific environmental barriers are not only dependent on type of housing but very much so also on building period [
3]. Besides the fact that such detailed analyses would increase the complexity of the present study to an extent that would motivate a study in its own right, unfortunately we do not have access to building year for the younger cohort. Still, with such evidence at hand, research could serve housing providers with useful information for refurbishment as well as new housing projects.
Overall, the younger old cohort is also in a better situation related to perceived aspects of housing (see Table
2). Although the differences are small for several variables, they are still significant for most aspects. The most pronounced difference between the two cohorts studied is related to external housing related control believes. As less influence over the housing situation has been shown to be associated with greater accessibility problems as well as dependence in ADL [
32], this is an important finding with implications for the home and health situation of very old, single-living community-dwelling people. Consistent with the ETA [
8,
9], the more favorable situation in usability for the younger old cohort reflects the fact that in an earlier phase of the ageing process people might have the capacity to maintain adaptive behavior even in situations exerting higher environmental press. Still, the participants in the very old cohort were as satisfied with their housing situation as those of the younger old. Keeping in mind the weakness of our study in terms of limited comparability between the two cohorts, we argue that the results demonstrate that in-depth investigations of different aspects of housing are necessary to increase the knowledge about the complex dynamics of home and health among different sub-groups of the ageing population [
10]. This complexity is further demonstrated by the mixed picture of differences regarding meaning of home between the two cohorts. The participants in the younger old cohort were in a more positive situation in terms of behavioral and social meaning of home, while those of the very old cohort rated physical and cognitive/emotional domains more favorably. As to the latter, this might reflect a stronger bonding to home based on familiarity and habits which in turn might counteract the willingness and ability to take action to change the housing situation. However, based on one single study with limited comparability between the two cohorts studied this is sheer speculation, but intriguing and worth further research. All in all, as elucidated in a recent study residential reasoning in very old age is a complex and ambivalent matter [
33], and professionals as well as family and older people themselves should be made aware of the need for increased attention to not only objective but also to perceived aspects of housing in counselling and intervention planning targeting older people.
During normal ageing, physical, mental and cognitive abilities as well as the ability to resist diseases decrease, which in turn increases the risk of symptoms and morbidity [
25,
34]. Hence, it was not unexpected that a larger proportion or participants in the very old cohort had more symptoms in each domain even though only the domain of head symptoms reached significance, (see Table
3). Still, only 4.5 % in the younger old cohort reported no current symptoms; the corresponding proportion in the very old cohort was 2.3 %. The largest difference was found in the domain of head symptoms, where a fourth of the younger old cohort and about half of the very old cohort responded that they had eye problems. This is worth noting because vision impairment by itself can lead to accessibility problems and ADL dependence [
35].
Depression is common among older adults and the incidence and prevalence increase with age [
36]. According to a review by Djernes et al. published in 2006 [
37], the prevalence of depression among older people living in ordinary housing or institutional settings varied from 7.2 % to 49.0 %. This large difference shows how difficult it can be to diagnose a real depression due to different methods and definitions. In our study using the GDS-15 scale, we found a higher prevalence of suspect depression in the very old cohort, which is consistent with previous findings [
38]. For symptoms of depression [
25] a higher proportion in the very old cohort reported higher numbers even though not significant compared with the younger old cohort, suggesting the difficulty in recognizing symptoms of a depression among very old people. However, once again the limited comparability between the two cohorts should be noted, but since the differences in aspects of health were in the expected direction we regard the new insights indicating differences in aspects of home should as valid and useful as a starting-point for further studies in this field of inquiry.
Since we had access to uniquely detailed data on objective and perceived aspects of housing collected with a younger old and a very old cohort, we used existing databases for this first, descriptive study to shed light on the situation of two different sub-groups of the ageing population. Naturally, a subdivision by chronological age includes a large group of people with marked individual variation as regards ageing as such. Another way to categorize people along the ageing process is to use Baltes & Smith’s definition of the third and the fourth age [
39]. The third age is a part of life after retirement which is characterized by economic security and without major limitations in activities caused by illness or disability. In contrast, the fourth age is the period of life when diseases and disabilities put limits on what an individual can or cannot manage to do, followed by increasing dependence on others to cope with daily activities [
40]. Accordingly, it might be more relevant to compare the two cohorts using the definitions of the third and fourth age. That is, out of 12 functional limitations about 50 % of the participants in the younger old cohort answered that they had one or more functional limitations, while on the other hand 10 % in the very old cohort stated that they had none (data not shown). Further, there were two individuals in the younger old cohort that were dependent in IADL as well as PADL, that is, per definition they were in the fourth age. The other way round, in the very old cohort 63 (17 %) of the participants were independent in ADL without difficulty and should accordingly be categorized as belonging to the third age (Table
3). These observations do not only highlight that chronological age might be questioned as the sole inclusion criterion in comparative studies of sub-groups of the ageing population. They also pinpoint the necessity of individualization regarding health promotion, prevention and interventions targeting the home and health situation of people in different phases of the ageing process.
Besides the weakness in terms of limited comparability between the two cohorts studied, there is a risk that the participation rate (i.e., 56 % in the younger old cohort and 45 % in the very old cohort) could jeopardize the external validity. Consequently, it is likely that the participants, especially those in the very old cohort, were healthier than average in the population. Further, the results could be somewhat biased also due to cohort effects, not just because of the age difference but because there was 7 years between data collection points. As to the data on objective aspects of housing, a noteworthy strength is that the dwellings studied are representative of the national housing stock in Sweden [
3].
Competing interests
The authors Henrik Ekström and Steven Schmidt declare that they have no competing interest. The author Susanne Iwarsson is the shared copyright holder of the Housing Enabler instrument and software, provided as commercial products (
www.enabler.nu).
Authors’ contributions
SI developed the concept of this study. HE, SS and SI were all actively involved in planning and designing the study. HE carried out the analyses, interpreted the results, and drafted the manuscript for submission. SI and SS contributed to the interpretation of results and the discussion section. In an iterative revision process, the three co-authors collaborated in finalizing the manuscript for submission. All authors approved the intellectual content and scientific relevance of the final version of the manuscript.