An internal report on the quality of GP practices in London has found one cluster performing significantly worse than the other five.

The document, released to HSJ under the Freedom of Information Act, shows north west London practices are significant outliers on quality.

Seventeen per cent of them are in the lowest ranking “review identified” category, compared to a London average of 12.8 per cent.

The category is the lowest of four, which are determined by data submitted to NHS London on 22 quality measures agreed by GPs, known as the General Practice Outcome Standards and Framework.

The data triggered a review of 71 of north west London’s 414 practices, the results of which are not known.

North west London’s practices account for 37.3 per cent of the 190 “review identified” practices across the whole of the capital.

The cluster contains two of the worst performing boroughs in London - Kensington and Chelsea, and Brent.

Twelve of the Royal Borough of Kensington and Chelsea’s 42 GP practices (28.5 per cent) were review identified and another 16 were “approaching review”.

Eighteen of Brent’s 70 GP practices (25.7 per cent) were review identified.

The report identified Hillingdon as home to the best performing GPs in London. More than 30 per cent of its practices achieved the top-rated “high achieving” category.

GP bodies dismissed the results of the outcomes standards.

Tony Grewal, medical director for their representative body Londonwide Local Medical Committees, said the “inappropriate” naming poor performers was “another example of how all information and can, and often will, be used against practices”.

“The original aim of this framework was to prevent the implementation of onerous and non-evidence based dashboards,” he said. “It was intended as a tool for practices to identify areas for improvement and as a source of information for patients.

“Sadly there are neither the resources or any system for delivering the resources that are much needed to address these issues.”

Clare Gerada, chair of Royal College of GPs’ council, said: “The labelling of practices as ‘review identified’ in the document would simply be because they are an outlier practice.

“I strongly suspect that the reason some are outliers is based on their unique patient population rather than on any sort of ‘failing’ by the practice.”

Worst performers

Proportion of review-identified practices

Kensington and Chelsea: 28.6 per cent

Camden: 25 per cent

Brent: 25.7 per cent

Haringey: 21.5 per cent

Croydon: 20.6 per cent