Children between the ages of 1 and 12 years (National Institutes of Health, 2022) are admitted to hospitals for many reasons. Often, hospitalisation is challenging for children as it disrupts their everyday routines (Ari et al., 2019). Coupled with the potential of encountering painful treatments (Delvecchio et al., 2019), such as procedures involving needles (Birnie et al., 2018), children are often faced with a sense of vulnerability, which evokes feelings of stress or distress (Ari et al., 2019). The latter occurs when stress is intense, prolonged, or combined (Marks & King, 2024). As these feelings can be anxiety-provoking among children, they frequently exhibit their nervousness through regressive behaviour or a reluctance to cooperate (Delvecchio et al., 2019), therefore making hospitalisation a challenging experience. Children may also perceive hospitalisation as a punishment, complicating their understanding that the medical care is intended to improve their well-being. As a result, this may impede timely medical interventions, extend procedures, and diminish patient satisfaction (Lerwick, 2016), consequently prolonging hospitalisation, which further exacerbates stress, distress, and anxiety in children (Delvecchio et al., 2019). Therefore, pain, anxiety, and stress have significant implications for a child's psychological well-being. This is concerning given the importance of it in the lives of young individuals, as it directly influences their overall quality of life (Arslan, 2023).

Psychological well-being, integral to mental health, is defined as having both hedonic aspects (e.g. contentment, pleasure) and eudaemonic elements (e.g. meaning, satisfaction), along with resilience, which involves healthy coping mechanisms and emotion regulation (Tang et al., 2019). The psychological well-being of paediatric patients within hospital settings can be evaluated by examining both positive emotions (e.g. enjoyment, emotional regulation) and negative emotions (e.g. stress and anxiety) experienced during medical procedures (Arslan, 2023; Moerman et al., 2019). Common scales used to measure these emotions include the Observational Scale of Behavioural Distress (OSBD), developed to assess distress experienced by children during painful medical procedures (Jay & Elliott, 1984), and the State-Trait Anxiety Inventory for Children (STAIC) (Muris et al., 2017). Anxiety is a prevalent feeling often observed in hospitalised children as they intensify their emotions of fear and apprehension, therefore, managing it is essential to maintain healthy well-being (Crossman et al., 2018). Arguably, if this is not effectively addressed, it has the potential to hinder children's development by raising the likelihood of adverse psychological outcomes during their recovery.

Play therapy has traditionally been used to address these issues in children as it aids with behavioural problems, such as anxiousness and trauma. Children can express their feelings by engaging in play and acquire new coping mechanisms (Gupta et al., 2023). Play has been widely acknowledged as crucial for children's healthy growth and development as it provides psychological support in alleviating stress and anxiety through the child's daily routine (Li et al., 2016). During hospitalisation, it helps children navigate unfamiliarity while fostering an environment where they feel comfortable expressing their worries, establishes a greater sense of security (Koukourikos et al., 2015) and reduces preoperative anxiety and pain (Díaz-Rodríguez et al., 2021). Therefore, paediatric nurses uses play while caring for children as it enhances the nurse-patient relationship by fostering a rapport while facilitating communication and medical interventions when children feel more comfortable (Godino-Iáñez et al., 2020). Examples of play include age-appropriate toys or video games (Rokach, 2016), storybooks, music and role-play (Gupta et al., 2023). Although the benefits from play therapy are aplenty, children are noticed to partake in fewer periods of play when hospitalised. When they engage in playing, it is noted to be reclusive and repetitious (Rokach, 2016). Coupled with the global shortage of healthcare workforce (Džakula et al., 2022), it further challenges healthcare professionals in engaging meaningful play with children amidst heavy workloads. However, introducing social robots, a relatively novel technology, may be helpful in this instance.

Social robots are designed to captivate and interact with humans using cognitive-behavioural distraction methods. They can be conventionally programmed to accomplish tasks such as making jokes, telling stories and singing songs (Onyeulo & Gandhi, 2020; Rossi et al., 2022). This is similar to what traditional play can provide for a child's cognitive, emotional, and social development. These comparable advantages can offer the same kind of mental stimulation and emotional comfort as traditional toys (Ihamäki & Heljakka, 2021), which makes social robots a promising complement to traditional play. Additionally, it shows their potential to positively impact children by not only distracting them but also enhancing their ability to cope with challenging circumstances by diminishing anxiety and possibly alleviating pain (Oliveira et al., 2020). The NAO and MEDi (Medicine and Engineering Designing Intelligence) robots are examples of social robots capable of such tasks (Fig. 1a & 1b). Not only do their interactive traits entice a child to play, but their ability to navigate and interact autonomously also makes them valuable in diminishing the workload of healthcare professionals (Getson & Nejat, 2022). Another example of a social robot is the huggable robot that resembles a teddy bear (Fig. 1c). It features an endearing exterior capable of exerting a stress-alleviating effect on unwell individuals (Moerman et al., 2019). Research has shown that there have been positive outcomes with the use of social robots in healthcare settings, suggesting the effectiveness of diversion techniques in reducing pain, anxiety, and fear among children (Nishat et al., 2023; Rossi et al., 2020).

Three systematic reviews have evaluated the efficacy of social robots in enhancing children's well-being (Littler et al., 2021; Moerman et al., 2019; Triantafyllidis, Alexiadis, Votis, & Tzovaras, 2023). These reviews provide evidence suggesting that social robots can benefit children's healthcare services. According to Littler et al. (2021), social robots effectively reduce anxiety and distress levels. Moerman et al. (2019) highlighted that these robots serve as a distraction, thereby alleviating stress and pain. Similarly, Triantafyllidis et al. (2023) found that the engaging characteristics of social robots promote compliance with medical procedures.

However, there were several methodological shortcomings in these systematic reviews, which includes a lack of comprehensive meta-analysis, and the limited scope of psychological effects measured, as some reviews were focusing on improving nutrition education or preventing obesity. Additionally, the literature search was restricted to only two databases, and grey literature was not considered. Both Littler et al. (2021) and Triantafyllidis et al. (2023) included studies with exploratory and observational designs, increasing the risk of confounding and observer biases (Hess & Abd-Elsayed, 2019). Therefore, in this systematic review, the aim was to improve the methodological quality by including randomised controlled trials (RCTs) that evaluate the psychological effects of social robots on hospitalised children.

Despite social robots' demonstrated practicality and utility in medical settings for improving children's well-being, their deployment remains relatively new. Given their promising potential in health services, the current systematic review will primarily examine their psychological impacts, aiming to address gaps in the existing literature and overcome methodological limitations identified in prior reviews. The research question identified to guide this review is: 1) What is the effectiveness of social robots in reducing anxiety, stress/distress or pain in hospitalised children?