The relationship between spatial characteristics and social interaction of older adults with dementia in nursing homes

ABSTRACT Various factors can contribute to the improvement of quality of life among the older adults living in facilities, but promoting social interactions can enhance the quality of life. There are some studies conducted on social interaction of institutionalized older adults, but only few studies in terms of spatial configuration. Therefore, this study intends to find the social interaction of the older adults in two nursing homes with different sizes and layouts, and to investigate the relationship between spatial characteristics and social interaction. The subjects of this study are two nursing facilities located in Seoul, Korea. The methodologies of this study include snapshots for observing social interaction and VGA technique for visual accessibility. As results, it was found that social interaction occurred more frequently in the large-scale facility, case 2. However, there is a weak negative relationship between the social interactions and the visual accessibility in case 1 only; it means that the interactions frequently occur in relatively segregated spaces. This study has its significance as it is the first combined study to understand the social interaction pattern of the older residents in connection with the spatial configuration of nursing homes in South Korea as a quantitative analysis method.


Introduction
In 2020, the number of people with dementia worldwide has exceeded 50 million, and the number of dementia patients is increasing by 10 million every year (World Health Organization 2020). According to World Alzheimer Report 2016, much of the increase in the number of people living with dementia will be in Asian countries such as China, India, and other counties in this region. The main reason for this is the rapid growth of the aging population in the Asia region, as over 56% of the aging population in the world resides in Asian countries (United Nations 2015). Korea, where the population is aging at the fastest rate in the world, became an aged society within a short period of 17 years since it entered an aging society in 2000, and is predicted to face the advent of a super-aged society in about eight years, in 2025 (Statistics Korea 2016). This increase in the older population is accompanied by an increase in the number of patients with geriatric diseases such as Alzheimer's disease (Prince et al. 2016). Most of the older adults with dementia prefer community care to facility care (Wieland et al. 2010). However, the enormous physical and time burden of caring for the older adults with dementia and the need for professional care are major reasons that many patients with dementia live in care facilities such as nursing homes. The rising demand for care facilities is leading to a steadily growing number of such facilities (Asakawa et al. 2009).
The older adults residing in care facilities can experience increasing physical disabilities while living in such facilities (Shimazaki et al. 2001) and tend to feel relatively more depressed and anxious and less interested in participating in activities that cause social disconnection and a relatively lower level of quality of life compared to the older adults living in the community (Hyun et al. 2012;Oh and Choi 2005). Various factors can contribute to the improvement of quality of life among the older adults living in facilities, but promoting their social interactions can be a way to enhance their psychological and physical health as well as social health (Greaves and Farbus 2006).
There are diverse factors in promoting interactions of older residents in nursing homes. These include facility operation systems including visitor control regulations, the personality of caregivers and staff, health condition of the residents, care and therapeutic programs administered in the facilities, its location and the number of participants of the programs, as well as the physical environments of care facilities (Burgio et al. 2001;Haq and Luo 2012;Kim H. S. 1998a;Nakrem, Vinsnes, and Seim 2011;Calkins 2003;Wanyenze et al. 2010;Khan 2012). In particular, for institutionalized patients, physical environments can play a role in improving their life quality by promoting social interaction using spatial function and layout (Haq and Luo 2012;Lee 2005). Several previous studies demonstrated that spatial configuration affects social interaction, but these studies were focused on workplace or hospital settings (Hendrich et al. 2009;Penn, Desyllas, and Vaughan 1999;Sailer and McCulloh 2012;Trzpuc and Martin 2010). Only two preceding studies dealt with the spatial configuration of facilities for the older adults and their social interaction. First, Lee & Lee (2020) performed a simulation-based study to predict the interaction between nurses and residents in four nursing homes in Korea, focusing on the location and visibility characteristics of nursing stations. Ferdous and Moore (2015) conducted an observational study on three long-term care facilities in the United States, to analyze the relationship between the accessibility and proximity of social space and social interaction among residents. Few studies have been conducted to identify the actual interaction patterns of the older adults living in facilities and examine them in relation to spatial configuration from a quantitative point of view. Therefore, this study intends to find the social interaction patterns of the older adults living in two nursing homes with different sizes and layouts, and to determine the relationship between spatial characteristics and social interaction.

Literature review
To help better understand the context of this study aimed at identifying the relationship between the social interaction patterns of the older adults living in nursing homes and the spatial characteristics of these facilities, a literature review was first carried out to define the trends in previous studies on spatial behaviors in care facilities and the space syntax theory in relation to care facilities.

Spatial behaviors in care facilities
A long-term care facility such as a nursing home is a residential space where the older residents lead daily life, and a service space where educational and leisure programs and care services are provided. Many previous studies addressed the spatial use behaviors of the older adults living in facilities. The factors reported to affect spatial behaviors in some major studies are as follows.
First, Lee (2005), after examining the program participation behaviors of the older residents in care facilities, noted that the venues of programs operating in such facilities change depending on program types and the number of participants, influencing the spatial behaviors of residents (Lee 2005). This study reported that spatial behaviors differ depending on whether a program is run for all residents in a specific space on a specific floor or for an unspecified number of people in an open space, or on a small-scale or individually for each residential unit. The study also mentioned that the program venues may vary depending on the plane structure of the facility (e.g. courtyard or doubleloaded corridor types), which may affect spatial use by the older residents. Calkins (2003), citing M. Powell Lawton's five design principles-orientation, negotiability, personalization, social interaction, and safety-for long-term care facilities, noted that social interaction, one of the principles, is affected by the availability of a number of different spaces and the diversity of activity programs provided (Calkins 2003). In addition, he and his colleagues observed that spatial size is also a factor influencing spatial behaviors in their earlier study, associating smaller units, which accommodate fewer than 20 residents, with less anxiety and depression and more mobility, social interaction, and friendship formation (Day et al. 2002). On the other hand, Wanyenze et al. (2010) and Khan (2012) suggested that care facilities' regulations for controlling visitors (target of control, number of allowed visits, visiting hours, range of accessible spaces, etc.) and program operation policies affect spatial use by the older adults living in the facilities, while providing the evidence for the impact of the spatial layout of care environments on user behaviors (Nayma 2012;Wanyenze et al. 2010). Calkins, sharing this view, reported the same observation as well as that the characteristics of the built environment along with the organizational policies and procedures of longterm care facilities affect the cognitive, emotional, and physical functioning of the residents (Calkins 2009). He stressed that, of these factors, the characteristics of the built environment have a positive effect on depression and anxiety among the older adults living in facilities, so they should be considered before implementing any pharmacological intervention to treat such conditions. Finally, he identified four factors that affect the spatial behaviors of residents in long-term care facilities. These include individual factors such as the sociodemographic characteristics, degree of dementia, and health condition of residents; interpersonal or social factors involving relationships with other people; organizational factors including the rules, policies, and culture of care facilities; and the physical environment (Calkins 2009). With regard to the spatial characteristics of care facilities, Ferdous and Moore (2015) found that a space with high visibility is used by a large number of people, while the residents of long-term care facilities interact more with others in a more segregated space. On the other hand, Yang, Lau, and Ho (2020) reported that the higher the privacy of the bedroom in a care facility, the stronger the tendency to move less among residents, with more formal interactions. In this way, the physical features of care facilities affect spatial use behaviors, and this study will examine the effects of nursing homes with different sizes and layouts on the social interaction of residents.

Previous studies on space syntax theory associated with care facilities
Space Syntax is a methodology or a set of techniques for the analysis and interpretation of the spatial configuration of buildings in order to understand probabilistic spatial behaviors such as movements, interfaces, etc. (Hillier 2007). Since the late 1990s, space syntax theory has been increasingly applied to studies of care environments, and most have pertained to healthcare facilities with few studies focusing on nursing homes for the frail older adults in relation to their daily behaviors in the facilities (Haq and Luo 2012). A majority of the studies deal with workflow (or movement flow) or work efficiency in relation to the interaction between staff, or staff and patients, mainly from the perspective of staff (Koch and Steen 2012;Lu, Peponis, and Zimring 2009;Nayma 2012;Sailer et al. 2013), while some studies were focused on the patients' viewpoint (Nayma 2012;Wanyenze et al. 2010). In spite of the particularly different subjects of the previous studies, they have all focused on users of spaces. The users of different categories such as inhabitants, care staff, nurse, visitor, etc. play an important role in creating various degrees of interfaces. The interfaces have an influence on creating interaction of the older adults living in nursing homes .
Syntactic attributes, such as physical and visual accessibility by Visual Graph Analysis (VGA), have been suggested to have significant effects on interfaces, workflows, or organizational performance in care environments including hospitals (Cai and Zimring 2013;Lu, Peponis, and Zimring 2009). With respect to physical accessibility, Khan (2012) also stated that actual walking distances (path distance) and common journeys taken by staff are largely affected by the design and layout of facilities (Nayma 2012). In terms of visual accessibility, most of the previous studies that applied VGA equally extended in all available directions from each position in a facility ). On the other hand, some other studies developed a method for a specific purpose. For instance, Cai and Zimring (2013) introduced two relational metrics: the team-based metric and the peerbased metric, in order to develop visual metric step depth as well as generic visual step depth (Cai and Zimring 2013). Similarly, Lu, Peponis, and Zimring (2009) developed Targeted Visibility to interpret reality of visibility analysis of some locations with greater weights than others when people deploy themselves or move around particularly in these settings (Lu, Peponis, and Zimring 2009). They argued that Targeted Visibility is more useful than generic visual connectivity in studies when analyzing the interaction patterns of nurses with a stronger relationship between the density of all nurses and the density of the nurses interacting. Many researchers have developed different analytic methodologies for spatial classification in line with their research purposes, but these methodologies commonly assume that the accessibility of space affects spatial behaviors. This study adopted the VGA technique to identify the effect of visual accessibility on the interaction of the older adults in nursing homes, measuring the accessibility at the knee level including that of basic furniture and fixtures in consideration of the influence of their arrangement on the use of space. As measurement variables, connectivity, which can help identify the connections between spaces, and integration, which represents the spatial depths on the network of all spaces, were used.

Case overview
The subjects of this study are two municipal skilled nursing facilities located in Seoul, Korea. As of 2020, a total of seven municipal nursing facilities are operating in the Seoul area. Some of these facilities are cooperating with other facilities including senior welfare centers installed in conjunction with them or have similar spatial layouts with others. With the exception of these facilities and others with limits in collecting data and obtaining research permission, two nursing homes with different sizes and spatial layouts were finally selected for this study. These two cases, as purpose-built care facilities, are successfully operated and managed with support from the Seoul Metropolitan Government, and have the same criteria for selecting residents, including financial capability and health level. Currently, patients with mild to severe dementia reside in both facilities. However, in Case 2 with a special nursing room, some patients with severe brain lesions also live together. These residents with dementia are randomly assigned to the same nursing room according to the similarity level of dementia, and there is no difference in the degree of dementia by floor.
An overview of the two nursing homes is as follows. First, Case 1 is a medium-sized building that can accommodate up to 165 people, with two basement floors and five floors above ground. Residents can access all spaces from the 1st to 5th floors in principle, but they cannot move between floors without the permission of the staff, so the space that they can freely access is limited to the floors where they reside (Table 1). Case 1 consists of two residential units that are symmetrical with the elevator hall in the center. Each unit has a double-loaded corridor structure, and five to six care rooms that accommodate four people each are located around the central corridor.
Case 2 is a large-scale facility with a capacity of 296 people and has one basement floor and five floors above ground. On the first floor are a large indoor garden in the center, a day care center and a reception near the main entrance, and a physical therapy room and a counseling room towards the inner side. The 2nd to 5th floors are residential spaces consisting of four residential units arranged in a radial configuration. Each unit is connected to the central lounge through a long corridor. Each residential unit has four to five care rooms arranged around the corridor, and as in Case 1, each room accommodates up to four people. Case 2, compared to Case 1, has a larger available space for residents. As dining and program activities take place in the central lounge, residents need to take a long journey on a regular basis daily, which is a distinct difference from Case 1. In Case 2 as well, residents are not allowed to move between floors without being accompanied by staff. These differences in spatial configuration and use are expected to affect the spatial behaviors of residents.

Methodologies
Before conducting the observation, this study was found to be exempt from ethical approval review by the Research Ethics Committee of University College London. Consent to participation in the research was then gained from the two facilities before the investigation began.
Prior to the main investigation, a pilot study was undertaken by informally following the older adults who could either walk independently or move by themselves using a wheelchair to investigate how they use the spaces in natural circumstances. Through the observation, it was possible to define the range of spaces actually available to the residents from each residential unit in the nursing homes. Residents had access to all spaces in their residential unit, except for staff-only spaces, as well as other residents' care rooms. In addition, they were able to freely use common spaces such as the living rooms of the other units than theirs. Based on the results of this preliminary investigation, the scope of the spaces to perform a spatial configuration analysis and an observational investigation was determined. On the other hand, in order to analyze the relationship between spatial characteristics and behaviors more accurately, even one large open space was subdivided into separate smaller spaces if they differed in functions. In Case 1, a large lounge was divided into one living room and two waiting areas by a table for diverse programs and meals installed in the center of the living room with surrounding benches (Figure 1). In addition, a buffer zone was created in consideration of the additional area occupied by each space while the spaces perform specific functions. For example, a buffer of 300 mm was placed in front of a booth-type bench, and a buffer of 500 mm was set around the table in the living room where chairs could be placed separately, considering the chair width. In Case 2 as well, the lounge in the center of the facility was divided into a dining area, a corridor, and a meeting area according to their functions, and the common space in each residential unit was also divided into a living room and a waiting area.
The methodologies of this study include observation utilizing snapshot and VGA analysis based on the space syntax theory. First, to capture the interaction patterns of the older adults living in the two nursing homes, snapshots were taken on a weekday where the same programs were operated for two weeks. The programs were administered five times a day-twice during the operating hours of personal care programs and three times during the free time according to the daily routine of the facilities. Depending on the size of the facility, the investigation involved four to five investigators. The number of required investigators, as well as observation spots, were determined through the pilot study by examining the space range that one investigator could cover and the location where observation could be easily made. Prior to the main investigation, pre-training on observation and documenting methods was conducted for the investigators. Lastly, space syntax was used as a method to compare and contrast the spatial configuration of two nursing homes and to see how the spatial configuration affect social interaction. Based on the Visibility Graph Analysis (VGA), only integration and connectivity of the two cases were used for this study. Thus, the accessibility of each facility was represented with VGA using Depthmap after including the furniture on the floors, as it has an influence on spatial behaviors (Turner et al. 2001). As described above, the spaces to be analyzed were limited to those that residents can use without the permission of the staff. In the modeling process of the spaces to be analyzed, to reflect the actual space use patterns of the nursing facilities in the spatial analysis, no syntactic depth was given to the care room and corridor spaces. This was in consideration that the transparent material used on the doors of the care rooms at eye level enabled observation at any time even if the doors were closed. Therefore, the two spaces were regarded as a single area. Based on these criteria, the spatial scope to be analyzed was determined and the spatial configuration analysis was conducted.

Results
This section first examines the interaction patterns of residents in the nursing homes and the spatial characteristics of the facilities, and then identifies the relationship between the two.

Interaction patterns in nursing homes
This study analyzed the number of residents recorded through snapshots. On the whole, Case 1 showed a relatively even resident distribution, with a total of 253 people, an average of 127 people per day, and an average of 25 per observation round (Table 2). Meanwhile, in Case 2, while fewer people were living in the observed residential units than in Case 1 (24 people in Case 1 and 20 people in Case 2), with the investigation range expanded to the spaces shared by the four units, the number of people observed was larger than in Case 1, at a total of 337 people, an average of 169 people per day, and an average of 34 per observation round. In both the facilities, more older residents were observed in the fifth round (17:00) when dinner preparation started. This trend was particularly prominent in Case 2, where residents from the fourunits dined together in the lounge. Meanwhile, differences were found through a comparison between the numbers of older residents observed in each round on the first and second investigation days although the observation was made during the hours where the same programs were operated.
These snapshot results can be visualized and organized according to users' types, movements, and interaction participation as shown in Figure 2. The types of users observed at the time of investigation were divided into older residents, resident staff such as caregivers and nurses, families, and volunteers. When the movement of a user was observed, an arrow was combined with the user type marker to indicate the direction.

Percentage of interacting users
During the observation, users were observed interacting with each other while participating in various activities. In Case 1, a total of 28 people engaged in such interaction 15 times, with an average of two people mutually interacting (Table 3). In Case 2, 88 people engaged in interaction 36 times, and the number of people mutually interacting was relatively higher than in Case 1. As a result of calculating the interaction participation rate based on the people occupying the space at the time of taking snapshots, 11.9% of the total occupants (253 people) in Case 1 and 26.1% of the total occupants in Case 2 (373 people) participated in interaction. It is clear that interactions occurred more actively in Case 2 based on the total number of occupants.
Of the people observed in the snapshots, interaction trends were examined in detail with a focus on older residents. The number of older residents observed at the time of investigation was slightly larger in Case 2 with 269 residents, than in Case 1 with 223 residents (Table 4). As a result of examining the characteristics of the interaction in which the older residents participated, all 15 interactions that occurred in Case 1 involved the older adults, with a total of 20 of them participating in the interactions. This figure represents about 9% of the total older residents. On the other hand, in Case 2, a total of 31 interactions were observed, and the number of participating older residents was 45, which represents about 16.7% of the total older residents. This indicates that the older residents in Case 2 engaged in social interaction more actively than the residents in Case 1.

Types of interaction
Interaction may have different significances depending on the target. This study examined the main targets of interaction that involved the older residents and found that they mostly interacted one-on-one with other older residents, staff, or their family members. On the other hand, the cases where the older residents interacted with two or more users were divided into five categories: interaction with older residents, interaction with staff, interaction with older residents and staff, interaction with family members of their own or other older residents, and interaction with older residents, family members, and staff (Table 5). In Case 1, all interactions involving the older residents were single interactions, and in Case 2, single interactions comprised the largest part of the total, at 77.4%. Among the detailed interaction types, single interactions between the older residents and staff accounted for the largest portion, and this type had a similar proportion in both the facilities (46.7% in Case 1 and 45.2% in Case 2). However, at the time of investigation, the older residents in Case 1 were observed as more active in interacting with the staff, initiating conversation with the staff first near the nursing station, which is visually and physically highly accessible. Among the types of interactions between older adults, one-on-one interactions were more frequent in Case 1 (33.3%), but with multilateral interactions including the older adults considered, 41.9% of the interactions occurring in Case 2 all involved the older adults, which suggests that interactions between older adults took place more actively in Case 2.

Interaction spaces
As a result of examining the patterns in the spaces where interactions involving the older adults mainly took place, the older residents of the two facilities showed different patterns in selecting interaction spaces. The older residents in Case 1 interacted mainly in the living rooms located within their residence units (46.7%), followed by their care rooms (26.7%) and nursing stations (13.3%) ( Table 6). On the other hand, in Case 2, care rooms were where most of the interactions occurred (32.3%), followed by the lounge (22.6%). In addition, waiting area 1 and meeting area 1 where the living rooms in each residential unit and the lounge can be seen were the third most common interaction spaces, each accounting for 12.9% of the interactions.
Since most of the older adults in Case 1 with a relatively smaller facility spent most of their time in the living rooms in their residential units except for the bedridden older adults and various programs operated in the living room, it seems that their interactions were concentrated in this space.  On the other hand, in Case 2, many interactions took place in care rooms where interactions between the older adults and staff frequently occurred during care services. In addition, it was observed that a highly sociable older adult group actively engaged in interactions, singing, and talking together in their care rooms. This seem to have contributed to the higher rate of interactions in the care rooms. Such interactions led by the older adults in the care rooms had the secondary effect of indirectly involving even the bedridden older adults who have difficulty in mobility in interactions. In addition, in Case 2 which is a large-scale facility, various kinds of common spaces such as living rooms, waiting areas, meeting areas, and a lounge were provided in each residential unit, and older adults interactions took place in a dispersed way in these spaces. The characteristic of the older adults' interactions observed within the common spaces in Case 2 is described as follows. In the case of voluntary interactions between older adults, they were divided into two groups depending on their preference on the interaction spaces: open spaces such as living rooms or the lounge, or spaces where these open spaces can be seen.

Visual accessibility by VGA analysis
In order to compare the differences in the visual accessibility between the two nursing homes, a VGA analysis was performed based on a single residential floor considering the actual mobility of the older residents. This study dealt with both connectivity and integration which demonstrate the accessibilities in terms of local and global spatial systems, respectively. As a result, the mean connectivity of Case 2 was more than twice that of Case 1, and the deviation of the minimum and maximum values of the connectivity of Case 2 was significantly larger than that of Case 1. In the case of integration, the mean, minimum, and maximum values of Case 1 were all higher than those of Case 2, indicating that the spaces of Case 1 had relatively higher visual accessibility. The intelligibility of each space was 0.94 in Case 1, which was relatively higher than that in Case 2 (0.88), suggesting that the spatial configuration of Case 1 was easier for users to understand (Table 7). For Case 1, the large corridor (mainly C2) formed by opening the entrances of the two units was the most integrated area and the connectivity did not differ from the integration, as represented by similar color variation. The corridor area (C1) connected with C2 and configured in front of the nursing station was also highly integrated and connected, while   care rooms were more segregated. Due to the large table placed at the center of the living room (L1), both connectivity and integration values of space behind the living room were dramatically decreased. Meanwhile, although there was a difference in color variation between connectivity and integration in Case 2, the corridor of C2, particularly at the junctions that link the corridors derived from different parts, such as from the two units at the top or from the dining area, was the most connected and integrated area. Similar to Case 1, care rooms were locally disconnected and globally segregated parts of the facility. When observing the spatial attributes according to the spatial functions of the two cases, the most connected and integrated space was the corridor in both cases (C1 in Case 1 and C2 in Case 2) ( Table 8). The least integrated and connected spatial attribute was the care rooms in Case 1. Similarly, the care rooms in Case 2 represented the least integrated space, with  Figure 3. Correlations between spatial attributes and normalised interaction.
the 12th lowest score for visual connectivity among 13 spaces. The most distinctive feature from these spatial attributes was the inverse relation of the living room. Specifically, high connectivity and integration were observed for Case 1, while relatively low values were found in Case 2. The differences seem to be caused by the living room type.

Relationship between spatial characprinceteristics and interaction pattern
This study correlated the spatial attributes with interaction so that we can quantitatively examine the effects of spatial configuration on the social interaction of the older residents. The normalized interaction was used to consider the effects of the size of the area instead of the generic interaction which is the number of interactions. The analysis of the relationship between integration and interactions showed no correlation in both cases. However, a weak negative correlation was shown between connectivity and interactions in Case 2 ( Figure 3). This implies that the accessibility of nursing homes does not affect the interactions among older residents, and the connectivity between spaces can partially affect the interactions. That is, this suggests that interactions involving the older residents occur frequently in a relatively segregated space with less spatial connectivity. However, considering that the interactions in Case 2 took place mainly in the care rooms, and that the interactions during care services accounted for a certain proportion of the total, it can be seen that the spatial configuration of nursing homes has an insignificant effect on the older residents' interactions.

Discussion
This study was conducted for the purpose of examining the effect of the spatial configuration of two nursing homes of different sizes on the social interactions among users and the following discussions can be made from the major findings.
First, the social interactions among older residents in nursing homes are not affected by the visual accessibility of spaces. Moreover, their interactions frequently occur in relatively segregated spaces due to a low level of connectivity between the spaces, which therefore ensures a high degree of privacy. In general, as in Case 1, a space with a straight double-loaded structure has been known to provide high spatial perception and increased spatial occupancy (Lawton, Liebowitz, and Charon 1970;Baskaya, Wilson, and Özcan 2004). However, a high level of visual accessibility does not necessarily link to the expansion of social interactions.
A study (Yang, Lau, and Ho 2020) that analyzed the degree of social interactions according to the privacy level of care rooms (bedrooms) in nursing facilities reported that the higher the level of privacy, the more formal interactions between residents were observed. In Case 1, there was no transitional space between the living room, a public space where various activities were performed, and the care rooms, a private space. In addition, the entrance to the care rooms was also open and configured facing each other around the living room, providing a relatively low level of privacy. It seems that the configuration and arrangement characteristics of these spaces influenced the social interactions between the older residents.
Second, in terms of spatial size and composition, large-scale facilities often subdivide the space to provide a variety of spaces with different functions and shapes. In relatively small-scale facilities, however, various functions are inevitably performed in the same space, which attracts people to the space. A number of previous studies have already reported that the shape and function of the living room affect the orientation, navigation, and social interaction of users (Calkins 1988;Choi and Yang 2007;An, Cho, and Yang 2008). The living room in Case 1 was located in the center of the building that had a double-loaded corridor structure and was found to have very high levels of connectivity and integration in the spatial configuration analysis. During the observation, social interactions frequently took place in this space. On the other hand, the living room in Case 2 exhibited the nature of a semi-public space, being located at the end of the double-loaded corridor, positioned towards the one side of the residential unit. The spatial structural analysis results indicate that the living room had similar levels of connectivity and integration to those of the care rooms. In addition, as the functions of the living room were distributed to the lounge, program rooms, and meeting areas within the facility, the occupancy rates of the residents decreased and their social interaction also remained at a relatively low level. However, it was observed that interactions between the older adults frequently occurred in private areas that were visually connected to public spaces such as the living room or lounge, suggesting interactions among the older adults can be promoted when the interaction spaces provide an adequate level of privacy. Therefore, when planning a nursing home for the older adults, it is important to include alcoves or other types of spaces connected to public spaces while considering the hierarchy of privacy of each space, as a way to vitalize social interactions among the older adults living in the facility. In particular, a living room with the same shape and layout as that of Case 1, where many people gather and various activities are performed at the same time, is not a desirable approach to spatial planning considering the peculiarities of this current era where the COVID-19 pandemic is ongoing. In the context of COVID-19, nursing homes generally control visitors from outside strictly, and the residents' life in the facilities are similar to normal. However, as the operation of some programs run by external experts has temporarily discontinued, the use of the living room in Case 1 or the program room and the dining area in Case 2 will be reduced. As each resident spends more time in his or her care rooms, the resident's interaction patterns will change and the frequency of interactions will drastically decrease. For the safety of residents, interaction in nursing rooms should be minimized, but the living room and dining area should be reorganized so that the minimum interaction can continue.

Conclusion
Nursing homes provide health-related care services like hospitals but are different from the latter because they are a type of residential facility for accommodating older adults with dementia. Therefore, they not only provide home-like environments, but also promote patients' social interactions with others. Social interactions are crucial for the quality of life of institutionalized dementia patients. This study was conducted to assess the effects of spatial configuration on social interactions of the institutionalized older adults. The analysis results found that the visual integration of nursing homes did not affect space users' interactions, and that only the spatial connectivity had an insignificant negative correlation in some cases. Therefore, the results suggest that social interactions of the older adults in nursing homes may be more significantly influenced by the institutional governance, such as the operation of programs and care services, access control, the staff's personality, the functions of the furniture pieces arranged in the space, and other factors, rather than spatial configuration. However, it was also observed that the provision of semi-public spaces that can assure privacy in large facilities may contribute to promoting interactions among the older adults.
This study was conducted on older adults with cognitive dysfunction and was intended to identify the characteristics of spatial use by observing their behaviors. This study has its significance as it is the first combined study to understand the social interaction pattern of the older residents in connection with the spatial configuration of nursing homes in South Korea as a quantitative analysis method. Yet, given that the social interactions of the institutionalized older adults are more greatly affected by other variables than by the aforementioned spatial configuration, it is considered that the behavior characteristics of the older adults can be more clearly understood when studied in conjunction with various factors such as users' sociodemographic and health characteristics, as well as the criteria for facility operation. Since this study was carried out only within a specific timeframe of two days on weekdays, a careful approach should be taken in generalizing the behavior characteristics of older patients in the relevant nursing homes. In addition, it is deemed necessary to increase the number of facilities to be studied for the general application of the study results and to institute a long-term followup of the same facilities and residents.