The report reveals staff costs - ?1,214 million for some 45,400 employees - made up 46 per cent of gross Prison Service operating costs in 2002-03. The service lost 668,337 working days - the equivalent of a year's work for 3,000 full-time workers in 2002-03 - at a cost of around ?80 million. Colin Moses, chairman of the Prison Officers' Association, said the high level of sickness absence was due to understaffing, attacks by inmates on employees, and the service's failure to offer occupational health support.