All district health boards have been told to review part of their cervical screening services after one failed to properly follow up treatment of some women.

The National Cervical Screening Programme said yesterday that the move to review colposcopy services, which investigate cervical abnormalities through a magnifying instrument, followed the Waitemata board's identification of failings.

Waitemata found that 28 patients had not been followed up within recommended times. Seven were high-risk patients who had had colposcopy; 21 were low-risk patients who had had colposcopy and treatment.

It made this discovery only when it undertook a review called for by Health and Disability Commissioner Ron Paterson while he was investigating the case of a cervical cancer patient made to wait too long.

In his report on that case, featured in yesterday's Herald, he criticised the board and two of its gynaecologists over their care of the woman in 2002-03.

The Maori woman in her 40s had to wait more than three weeks to be seen at North Shore Hospital's colposcopy clinic after being referred as an "urgent" patient - and nearly another month to receive her diagnosis. Under Health Ministry guidelines, she should have been seen within a week.

Her cancer was treated at another hospital and Mr Paterson's report said it was in remission.

He said the hospital repeatedly missed opportunities to take a cervical smear and it failed to fast-track appropriate treatment once her ulcerated cervix was identified.

The health board acknowledges it failed the woman, has apologised and says changes it has implemented have ended delays for suspected cancer cases.With the 28 other patients, it simply omitted to make appointments for some, because of "systems errors", while others had not kept appointments that had been made.

All the high-risk patients had been followed up and treatment was being undertaken and the low-risk patients had all been contacted.

The national screening programme said all DHBs' colposcopy services would be audited over the next two years. Because of Waitemata's problems, it would now be asked to review colposcopy ahead of the audits, although the programme's clinical leader, Dr Hazel Lewis, said she was not aware of problems elsewhere.