The health service is "awash" with patient information but many present "conflicting advice", wrote Dr Margaret McCartney.
The Glasgow-based GP said that patients are being given very different information about the effects of the same surgery, depending on where they live and which leaflets are used.
Writing on bmj.com Dr McCartney highlights a number of studies that found wide variations of the quality of information supplied in the leaflets.
There is an independent certification scheme, the Information Standard, funded by the Department of Health for organisations producing evidence based healthcare information for the public.
But the Information Standard's co-chair of the executive council, Muir Gray, told the journal that a slow uptake of the scheme means much of the information available is still not good enough.
Dr McCartney writes: "The NHS's multifarious patient information leaflets are inaccurate, inconsistent, and confusing and effort is duplicated because each trust commissions its own, often from the private sector.
"The size of the NHS makes this hard to do, but it is wasteful to franchise out the core role of information provision to the private sector because each trust is paying again for the same information over and over.
"This is one area of the NHS where efficiency savings look ripe for the picking."
An NHS spokeswoman said: "NHS England's patient and public voice and information team is to start a major project in September to lead on the standardisation of all information going out to patients.
This will involve engaging with clinicians, nurses, allied health professionals and IT. Once the information is developed, it will go through the standards process to have it appraised, approved and signed off for publication.
"NHS England believes that this piece of work is critical for patient-focused care. There has to be clinically endorsed, consistent information available across the country in order to improve trust and confidence with patients, their carers and primary/secondary providers of care."