Development of a machine learning-based sepsis prediction model for real-world clinical settings in South Korea: a single-center retrospective study.

Globally, all regions and places experience population ageing. Of all, Korea’s population is aging very rapidly. The working-age population and the elderly dependent population are decreasing, threatening the lives of the elderly []. As a result, people in their 60s are excluded from complete retirement and are opting to maintain their careers through measures like extending their retirement age or choosing reemployment after retirement []. In this situation, security worker is one of the most preferred occupations for seniors facing difficulties in employment and job search due to their age []. Currently, 21.3% of elderly workers aged 65 and above are working as security workers in Korea []. Apartment security workers are classified as "Elementary Workers" under the "Cleaning and Guard Related Elementary Occupations" category of the Korean Standard Classification of Occupations, which includes facility security []. Their primary responsibilities include monitoring activity both inside and outside the apartment building, regulating guest access, overseeing parking, accepting and documenting mail deliveries, maintaining cleanliness, sorting recyclables, and dealing with tenants’ concerns []. Elderly apartment security workers work in bad working circumstances, engaged in 24-hour and night shifts, and sleeping in small security guard posts [,]. Many demographic and health factors, including age, current smoking status, alcohol consumption [], and perceived health status [], have been linked to depression in security workers. Other work-related factors include job insecurity, low pay, threats and harassment from superiors, experience of violence [], irregular work schedules [], short rest time [], and emotional labor []. Notably, the sleep quality of shift workers, including apartment security workers, has been reported to be closely associated with depression []. Emotional labor is the process by which employees regulate or manage their feelings and expressions to achieve organizational goals []. When dealing with complaints and interacting with tenants, apartment security workers engage in emotional labor [,]. The majority of them are indirectly employed through subcontractors or service businesses, and because they are required to renew contracts annually, they are forced to endure unjust treatment by residents in order to minimize conflicts. Such emotional labor impacts them in various ways and leads to increased job stress and decreased job satisfaction, and it can result in cardio-cerebrovascular diseases, as well as various mental health issues including anxiety, agitation, anger disorders, social phobia, panic disorders, depression, and suicide []. Apartment security workers who repeatedly work shifts and night shifts experience low sleep quality. Apartment security workers had lower sleep quality compared to other shift workers in different occupations (nurses, male manufacturing workers) or elderly residents in the community []. Above all, shift work is related with impacts on sleep, depressed mood, and even suicidal ideation [].