# A Managerial Approach to Investigate Fall Risk in a Rehabilitation Hospital
## 1 Introduction  
According to the World Health Organization (WHO), falls are in the foreground as external causes of unintentional injuries, and they are usually defined as actions that consist of \"inadvertently coming to rest on the ground, floor or other lower level, excluding intentional change in position to rest in furniture, wall or other objects\" [1]. It is estimated that 391,000 people died in 2002 due to these events. In terms of hospital environments, falls represent a daily problem; hospitals, in fact, report from 700,000 to 1,000,000 falls every year [2], accounting for 20-30% of the adverse events reported overall [3]. Due to this high incidence, health departments must act in terms of management and prevention so that these events do not influence hospitals' quality levels. In addition, falls can determine an increase in the mean length of hospital stay (LOS) and/or additional non-scheduled readmissions after discharge due to fractures, anxiety,and depression that could be derived from these traumatic events [4]. Moreover, several studies have reported a mortality rate of 10.1% in older people within one year following a hip fracture [5]. Previous research in the literature reported numerous variations in fall rates, ranging from 4 to 14 falls per 1000 hospitalization days, corresponding to about 10 monthly falls in a 28-bed unit [6,7]. In the hospital context, it is necessary to identify patients who are at risk. Several evaluation systems can be found in the literature [8], with scores that allow one to quantitatively understand if patients are more or less exposed to fall risk, and these evaluation systems' scores are based on different variables. In the _Istituti Clinici Scientifici Maugeri_, the most recent operative instructions prescribe the combined use of the fall risk assessment tools known as the \"Morse Fall Scale\" (Morse scale) and \"St. Thomas Risk Assessment Tool\" (Stratify scale). The Morse scale evaluates six items: (1) history of falling, (2) secondary diagnosis, (3) ambulatory aids, (4) intravenous therapy, (5) gait, and (6) mental status. The total score defines three risk levels: 0-24, low risk; 25-44, medium risk; and \(\geq\)45, high risk [9]. The Stratify scale considers other aspects, in particular, history of falls, state of agitation, visual impairment, frequent toileting, and mobility score. The achievable score ranges from 0 to 4 with a score of \(\geq\)2, which confirms the existence of fall risk [4]. The availability of accurate and high-quality surveillance and monitoring systems that are supported by integrated information systems is fundamental for maintaining a high level of attention among medical staff with the aim of defining both the features and magnitude of the issues, directing interventions, monitoring progress by using appropriate indicators, and identifying sentinel events. Since the previous literature and evidence indicated that the monitoring and management of fall risk are complex and easily influenced by a plethora of factors (which could often lead typical fall risk screening tools to have a distorted view of the issue [10]), it has been hypothesized that investigating approaches that could allow a deeper overview of fall risk could aid in its limitation. To this aim, simulations have been proposed as an innovative solution in the healthcare field [11] due to the similarities that some healthcare systems present with other work environments [12]. In the context of simulation, discrete event systems (DES) have attracted much attention in the healthcare context due to, among other factors, the ability of this strategy to deal with complex problems, such as those encountered in healthcare settings [13]. To date, and to the best of our knowledge, DESs have been widely proposed to improve emergency departments' issues [14; 15; 16], but in the last few years, DES applications have appeared for several other functional areas/hospital settings [12; 13], among which rehabilitation units/hospitals can also be found [17; 18; 19; 20].