Inaccurate patient records could lead commissioners to carry out "unintentional innovation", researchers have warned.
Following a review of NHS data from HESonline, Imperial College London NHS Healthcare Trust stressed the importance of accurately capturing and coding patient episodes.
Published in the British Medical Journal, the review found 1600 adults aged 30 and above were incorrectly identified as attending outpatient child and adolescent psychiatry services in England during 2011.
Furthermore, the number of 0-19 year olds reported as attending geriatric services has been increasing steadily over the years with over 3000 attendances in 2009-10.
More "surprising" results included the presentation of male inpatient admissions to obseteric services (17,000), gynaecology (8,000) and midwifery (20,000).
As data from the HESonline will inform the decision making of new clinical commissioning groups (CCGs), the researchers concluded all clinicans "should examine the data being submitted by and about our services for unintentional innovation".