Introduction
Hospitalization is a stressful event. Being away from home coupled with the uncertainty of the outcome, the invasive nature of hospital procedures and the disease itself trigger a deregulation of the hypothalamic-pituitary-adrenal axis in charge of stress homeostasis [1]. This results in increased production and release of steroid hormone cortisol which has been associated with poor postsurgical outcomes [2], slower speed of wound healing [3] and increased odds of unplanned readmissions [4].
Children are more likely to suffer the deleterious effects of hospitalization. They are more susceptible to hospitalization-induced stress due to their physical and emotional dependence [5]. Furthermore, increased cortisol levels have been associated with long-lasting effects in wellbeing. For instance, children who were hospitalized for over a week had more chances to develop behavioral problems and learning difficulties during adolescence [6]. Also, high cortisol levels during childhood have been associated with poor cognitive functioning [7] and is a risk factor for adult clinical depression [8].
Altogether evidence shows that managing stress in the pediatric hospital environment is of uttermost importance for assuring an integral recovery of the patient. There are several approaches to manage stress in hospitalized children including clown therapy [9], expressive arts [10] and animal-assisted therapy [11]. Nevertheless, these rely on trained personnel or volunteers to be completed. In resource deprived settings, with shortage of both volunteers and personnel, the need to manage stress in hospitalized children is not met.
Emerging technologies such as virtual and augmented reality can be an option to traditional therapies since they do not demand additional personnel. Augmented reality (AR) is a technology that has gathered much attention recently due to its wide use. Nevertheless, the technology has been around since the 1980’s [12]. It consists in the superposition of digital information over physical objects and environments in such a way that the user-technology interaction is enhanced [13].
AR applications are amongst the most promising technologies in health. They are widely used in medical training [14] and surgery assistance [15,16]. Lately, AR-based therapies for psychological disorders have also been proposed and assessed. AR has been effective in diminishing fear and anxiety in patients with small animal phobia [17]. Furthermore, a clinical trial shows that all metrics of phantom limb pain improved after AR-therapy in patients whom conventional therapy had failed [18]. Since research in this topic is still limited, systematic reviews call for more trials to confirm the effectiveness of said therapies in those diseases and other psychological disorders [19]. The effect of augmented-reality-based therapies on stress as an outcome has not been assessed so far.
Books enhanced with AR technology have been in the international market for several years. They consist in a traditional book with unique markers that allow the visualization of digital content with the aid of a mobile device. Markers could be special graphics or symbols in each page that when recognized display the augmented medium. Some authors argue that AR books are the most promising application of AR technology in the educational field since books are now able to provide interactive experiences making them a dynamic source of information [20,21].
The aim of this randomized cross-over trial was to evaluate the effect of reading books with augmented reality technology on salivary cortisol levels in hospitalized pediatric patients. A visual analogue scale (VAS) to assess children psychological stress was the secondary outcome. A standard book, with no mobile device available, was used as a comparator.