The former head of the Care Quality Commission warned yesterday that parts of the NHS were still delivering unacceptably poor standards of care.

Cynthia Bower, the chief executive of the CQC from its foundation in 2008 until last month, said there was confusion in the NHS over how to drive up quality but clear indications of what was holding it down.

"There are too many organisations out there who are not getting the basics right. The last inspection I went on – of an NHS foundation trust – there were basic things it had got wrong," she said.

Speaking for the first time since she stood down from her £195,000-a-year post, Ms Bower admitted she had promised too much.

She announced her resignation in February following a series of events that had undermined confidence in the CQC, including the Winterbourne View scandal, where residents of a privately run home for people with learning disabilities in Bristol were abused by staff. It emerged that the CQC had ignored warnings about the home from a whistleblower.

The introduction next year of five-yearly revalidations for doctors, assessing them on their performance, was the "strongest driver of quality in the system and likely to have the biggest impact", she said.