Her comments at last week's NHS Alliance spring conference, follow a poll which showed that most GPs and practice managers feel PBC has not improved patient care.
Ms Hewitt assured delegates: 'I want to support the majority who understand the challenge and the minority who are lagging behind.
'I recognise that there are reasons why primary care trusts are finding it difficult to do what we want.
'Restructuring is partly to do with it as they are still putting their teams in place.
'But there are a lot of people who really get what world-class commissioning is about and have the skills to do it.'
Ms Hewitt said she accepted that the quality of data was holding some PCTs back, admitting: 'We're hugely behind many countries.'
In an answer to a question from the floor, the health secretary also offered her support for community foundation trusts, saying: 'It offers real opportunities for the not-for-profit and voluntary sectors.
'Commissioners can have a consortium of providers under the umbrella of a foundation trust. It has huge potential.'