The database search yielded 144 publications and an additional 20 from reference checking and Google Scholar search. After screening and inclusion assessment, thirty-four papers were assessed for full-text review. Five more articles were excluded due to content not relevant to the review questions. A total of 29 publications (n = 29) were included in the final review. Figure 1 shows the review flow diagram.
Of the included publications (n = 29), 24 items with quantitative experiential designs reported positive outcomes. Common outcome measures were agitation, anxiety, depression, loneliness, cognition, and quality of life. The majority of studies’ scope was relatively small and exploratory. A recent Australian study with 415 older people with dementia from 28 long-term care facilities was an exception [7]. Most research reported the use of PARO in nursing homes (n = 25). More publications were authored in Australia, US, and Japan. Only one Canadian study (n = 3 participants) was found [14]. Only one study reported family perspective [15] and staff experience [11]. Content analysis [13] identified reported benefits of and barriers to the use of PARO. Our analysis serves to identity the key benefits (some of them overlaps and interacts) and core barriers. See Fig. 2 for the final themes.
Benefits
Key benefits include: reducing negative emotion and behavioral symptoms, improving social engagement, and promoting positive mood and quality of care experience. Table 1 shows the benefits of PARO reported in publications.
Table 1 Benefits of PARO reported in included papers Reducing negative emotion and behavioral symptoms
One of the common targets for interventions in dementia is alleviating negative emotions and reducing behavioral symptoms. A recent Australian RCT compared PARO with a plush toy found a statistical significant but modest effect in reducing behavioral and psychological symptoms of dementia [7]. Other studies in Norway, US, and New Zealand also found that the social robot helped in the reduction of physical and verbal agitation [16,17,18,19,20]. PARO was also found to improve anxiety and improve depressive symptoms [6, 21, 22]. Evidence also indicated that the utilization of PARO reduced the use of psychotropic medication [19, 22,23,24], and combined with reduced wandering may reduce the falls risk [11]. These improvements suggested that the robot may result in reducing staff stress and caregiver burnout [25]. Some studies have reported the benefits in psychological and behavioral symptoms of dementia were more pronounced in those with less cognitive impairment [26, 27], and in individual as opposed to group settings [11]. Other studies showed older people with moderate and with severe dementia had a significant effect with PARO [21, 24]. The evidence was inconsistent and indicated the need for further research. It is also important to point out that the reporting of stages of dementia can be problematic in the literature as different cutting scores and scales were used in different studies.
Despite these positive findings, it was noted that staff in the residential care setting were challenged to use PARO effectively to provide care due to restricted work routines [28]. The experimential design of research prescribed fixed intervention time and dose, which did not always match clinical needs of residents in the care setting. In a staff experience study, PARO was reported to have many benefits and staff found it useful and practical for people with dementia to use [11]. Not every older person wanted to interact with PARO. One research reported that 1 out of 10 persons refused to interact with PARO [21]. Other studies did not report refusal rate.
Improving social engagement
PARO has been found to improve social engagement in individuals with dementia, increased activity participation, and promote more spontaneous communication [22, 25, 27, 29]. PARO helped to improve both verbal and visual engagement [7] in social interactions. In a study, PARO was utilized to facilitate conversations between the individual with a therapist [30]. In another study, PARO was highlighted to work as an ice-breaker between staff and residents, a social mediator or an impetus toward social interactions between residents [19, 31]. A U.S. study reported PARO’s positive effects on the activity levels of older people with dementia grew over 7 weeks, suggesting Paro offered more than “novelty effect” [29]. A study in Taiwan showed short-term interactions significantly improved the communication and interaction skills of participants in residential care [32]. When PARO was compared with a stuffed animal in Japan, participants talked more frequently to PARO and showed more positive emotional expressions with PARO [21]. Rather than reducing human contact, the researchers found introducing PARO may increase willingness of the staff members to communicate and work with elderly people with dementia, especially those with moderate dementia [21].
A staff experience study in Australia commented that PARO provided a sense of belonging and warmness: “when I saw them interacting with it… you saw their loving personality came back” [11]. Also, staff perceived that PARO gave older people with dementia (including males) confidence to talk with others around them: “The men don’t really tend to take with the babies a lot, whereas they did with the seal” [11]. In a storytelling study, participants in the PARO group not only spoke more words, but also were more articulate on the creation of story characters, setting and story [37]. It was suggested that improved communication contributed to more calmed behaviors and improved mood [19, 25], and reduced loneliness [14]. Some studies indicated improved social engagement persisted for longer than a year [3, 33].
Promoting positive mood and quality of care experience
Multiple studies have found improvements to positive emotions and behaviors in individuals with dementia interacting with PARO. PARO has been noted to help individuals become more active, smiling, relaxed and comfortable, more likely to laugh, and to have brighter facial expressions [23, 32, 34]. It has also been found to improve participants’ mood and the quality of care reported by caregivers, as well as the level of comfort observed by families [7, 35]. Increased quality of life and pleasure scores with the use of PARO have suggested improvement in care experience [7, 26]. Other studies have demonstrated positive effective in sleep [16, 19] and pain medication use [6]. In a quality of life research, the participants who spent time with PARO (intervention group) showed to have a sustained improvement in quality of life, in comparison to a worsening trajectory in the control group [23, 24]. The intervention group used significantly less psychotropic medication compared with the control group. Family interviews in a study [15] found families reported PARO was something to love, offered meaningful stimulation, and companionship. Family comments included: “Everybody I saw with it, it certainly seemed to lighten their mood” and “I think for her it’ a companion, somebody to talk to, she’s not lonely”. Overall, evidence showed PARO may help to stimulate memories, promote positive mood and quality care experience [19].
Barriers
While the social robot PARO offers technological opportunity in supporting dementia care and managing difficult behavioral symptoms, the adoption of PARO in care setting remains low. Key barriers to the adoption of the technology include: cost and workload, infection concerns, and stigma and ethical issues.
Cost and workload
One identified barrier to the uptake of social robot is cost and added workload to staff. Since PARO was often used individually or in small groups, the initial cost of purchasing a unit was brought up as a barrier to use in care settings [15, 17, 20, 32]. The current cost of the robot is US$6000. Although there is government support in some countries such as U.S. and Japan (as PARO is certified as a therapeutic medical device), most healthcare organizations in other countries have to purchase their own. The high cost can lead to a concern in innovation dissemination, fair distribution, and equity in the robotic use [10]. Currently, universal access by fair opportunity to assistive technologies is an ideal but not a reality. A few studies also highlighted ongoing maintenance, cleaning and repair can be an added cost [17, 36]. Additionally, staff education and skill at facilitation and application have been identified as important aspects of using the robot so PARO may be perceived as additional workload for caregivers and staff [15, 32, 35]. A few studies also brought up a concern that with patients in distress and frustration, PARO may be damaged and may not be able to sustain in shared use with multiple residents within care facilities [3, 22].
Infection concerns
Another key consideration is infection prevention and control. Studies highlighted that it can be difficult to keep PARO’s fur clean [11, 38], and that the fur covering is not designed to be regularly removed or machine washed, which may post a concern especially to individuals who are immunocompromised [3, 22]. To keep to a minimize the spread of pathogens, the recommended protocol involves cleaning PARO between contact with different users [35], which may be seen as an added workload to staff in facilities. In a UK study at a general hospital over 9-month of time, PARO was used with a hospital infection control protocol and found to be within the benchmark threshold for cleanliness [9]. The authors commented, “However, during this study the time allowed for cleaning in the cleaning protocol was considered by the staff to be long and onerous. This had the potential to limit the use of PARO by affecting perceived workload” (p. 39).
Stigma and ethical issues
The stigma of interacting with a robot animal was another concern identified by caregivers and staff. Some authors raised the ethical question that the use of robots in dementia care creates risk of infantilizing and dehumanizing care [10]. Research noted that individuals might feel as if they are being treated like children, and the robot being seen as “toylike” [11, 15, 35]. Some cases described individuals as appearing embarrassed about interacting with PARO especially in front of others, and this might have influenced their reactions [39, 40]. It was noted that this might be of particular concern to men, who seem to respond less positively to PARO in some studies [40, 41]. As previously mentioned, however, male residents in another study responded positively with PARO [11]. This suggests the gender factor should be further investigated.
In some cases, interventions with PARO caused negative emotional responses, including anger, wandering, fearfulness, and agitation [17, 20, 35]. Studies postulated that some individuals may have had past negative experiences with animals, therefore, consideration should include the person’s biography, particularly their like and dislike of animals [42]. It was noted that when using PARO, staff should uphold a person-centred approach, as just because the resident liked PARO 1 day does not mean that he or she will enjoy it the next [26]. Some staff and family raised concern that PARO’s vocal sounds and movements could be distressing [38]. Trying to engage patients who were not interested could lead to increased agitation [36, 40]. PARO was found to not have the option to easily turn off because its hidden switch between the split tail fins; older people with dementia did not know how to turn the robot on or off [43]. Removing PARO was sometimes noted to be difficult [36]; after several weeks of removal of PARO, one study found increased depressive symptoms at follow up [27].
Some studies described situations where PARO appeared ineffective for some individuals or lost effect over time [34, 41]. The differences in how specific subgroups may respond to the robot remain unclear and need further research. A few studies noted engagement was less likely with males, and those who were more cognitively impaired tended to interact with PARO and not with other humans [6, 41]. For example, we do not know whether or not an individual’s previous positive experiences with animals could affect level of engagement [38]. The perceptions of PARO as a pet versus as a therapeutic tool might differ depending on cultural acceptance [42]. Regulating the robot as a medical device has disadvantages (e.g., keeping the price high and inequity of distribution) and advantages (e.g., safety regulations). Table 2 offers practical advice to draw on for stakeholders who are responsible for addressing barriers and ensuring safe, competent and ethical application.
Table 2 Key barriers and implications