NHS waiting time data for elective surgery 'unreliable'
23 January 2014 Last updated at 19:09 GMT
The National Audit Office says some waiting time figures published by hospitals - one of the key targets for the NHS in England - are unreliable.
The waiting times relate to non-emergency operations like hip and knee replacements.
The Patients Association says "fudging the figures" diverts attention from providing high quality care.
Branwen Jeffreys reports.