A team from Imperial College found that in 2009-10, nearly 20,000 adults were coded as having attended paediatric outpatient services, and 3,000 patients under 19 were apparently treated in geriatric clinics. Even more striking, between 15,000 and 20,000 men have been admitted to obstetric wards each year since 2003, and almost 10,000 to gynaecology wards.
It's hard to put your faith in analysis, visualization, policy, and anything else that comes out of data with reports like these. With human error being a known issue, we have to find better ways of inputting and double-checking data. Unfortunate mistakes at the outset only lead to bigger problems down the line.