Sleep-deprived employees are costing the South African economy billions of rands, a recent study conducted by Charles King, an MBA student at the University of Stellenbosch Business School (USB) has revealed.The research indicates that sleep-deprived employees are at higher risk of life-threatening chronic illness and disability, and they are more likely to cause workplace accidents.They are also less productive and often absent from work – adding up to an economic liability resulting in the loss of billions.According to the study, the cost to just one medical aid scheme of treating the life-threatening diseases linked to sleeping less than the recommended eight hours a night is estimated at R22bn annually. He set out to determine the expected savings in healthcare costs if 25- to 40-year-olds could be converted to healthy sleeping habits in a world that expects employees to be “always-on”.“Lack of sleep is not only related to workplace issues such as absenteeism, lack of productivity, poor work performance, and accidents – which have a direct cost impact on a business – but insufficient sleep has been directly linked with seven of the 15 leading causes of death. The research looked at the indirect costs of lack of sleep, particularly the cost to medical schemes of treating illnesses where inadequate sleep is a major risk factor. We asked what the potential savings would be to a medical scheme if individuals just got enough sleep,” King says.It is widely accepted that seven to nine hours sleep a night is optimal for wellness, productivity and lowering the risk of disease, but King said two-thirds (64%) of the people whose sleeping habits he tracked slept for less than seven hours a night, with men more likely to be sleep-deprived.Sleep problems have become one of the leading causes of physical and mental health illnesses, due to expectations of being always available, shift work and longer working hours, 24/7 availability of entertainment and addiction to technology such as mobile phones.Even one night of fewer than six hours sleep is equivalent to two totally sleepless nights. It impacts cognitive performance – impairing memory and concentration, and making risky decision-making more likely – and the risk factors for disease increase exponentially as sleep time decreases below the seven-hour mark.King says that an average of fewer than seven hours of sleep increased the risk of developing major depression by 22%, coronary artery disease by 73%, type 2 diabetes by up to 18%, and the risk of developing colorectal cancer by 50%.Those who don’t get enough sleep, he says, are subject to a double jeopardy scenario – lack of sleep is a contributing factor to obesity, and both are individually linked to increased risk of cardiovascular disease, depression, cancers, and diabetes. Participants in King’s research into sleeping habits who slept for less than six hours a night had a body-mass index (BMI) 12% greater than those who slept for the recommended seven to nine hours, while those who slept for less than five hours a night had some of the highest BMI measurements.To ensure healthy sleep, he said the use of mobile devices, watching TV or working in bed should be avoided, along with consumption of nicotine, caffeinated drinks or any substance that would impair sleep quality, while regular exercise had significant benefits to improving sleep. “It is important to educate people on the health benefits of healthy sleep norms, as well as the health risks of not getting enough good quality sleep,” he says.