The government has failed to evaluate the cost-effectiveness and consequences of its plans to improve patient access to GPs, and has "a limited understanding" of the pressures currently being faced by the sector, concludes a new report by the National Audit Office.

The Department of Health and NHS England have "a high-level vision" for improving access to general practice and have increased the funding available, "but are seeking to extend access despite failing to provide consistent value for money from existing services," the NAO said.

NAO analysis indicates that the minimum additional capacity needed to achieve the new commitment equates to £230 per appointment hour per 1,000 registered patients. In core contract hours, the cost is an estimated £154.

NHS England says additional funding will be used to also cover transformation costs and deliver wider improvements in access, but it has not explained how it will ensure that the additional funding provides good value for money.

The report also warns that NHS England and Health Education England's efforts to increase the GP workforce "are at particular risk from falling retention, shortfalls in recruitment and increases in part-time working", and that "supplying sufficient numbers is challenging". NHS England is supporting general practice to employ a wider staff mix "but the incentives for practices to employ staff cost-effectively are not yet aligned".

It also says that clinical commissioning groups should be better placed than NHS England to identify emerging problems with access, but that some commissioners have "a limited understanding" of whether services are meeting patient needs, and have "limited capacity" to manage any significant changes. Also, "limited levers" to manage performance and problems with service restructures "leave commissioners in a weak contractual position," it noted.

"Without a more co-ordinated approach and stronger incentives to secure the desired results, the NHS is unlikely to get optimal value for money," stressed NAO head Amyas Morse.

Commenting on the report, Professor Helen Stokes-Lampard, chair of the Royal College of GPs, said: "The NAO hits the nail on the head by questioning the cost-effectiveness of forcing GP surgeries to deliver routine services seven days a week in the current climate. Unfortunately, it fails to demonstrate a clear understanding of the enormous pressures GPs are under - and the valiant job they do - in trying to deliver care to millions of patients every day, in increasingly difficult circumstances".

"It seems bizarre that the NAO are questioning the cost-effectiveness of boosting the GP workforce by 5,000 over the next five years when today alone, over 1.3m people will visit their GP surgery and GP teams are seeing 60m more patients per year then we were even five years ago. Meanwhile, the number of GPs has remained stagnant and the share of the NHS budget stands at just over 8 percent," she argued.

"If general practice fails, the rest of the NHS collapses behind it. That's why we urgently need NHS England to deliver in full on the pledges it has promised in the GP Forward View, swiftly and effectively, and for all governments in the UK to invest properly in the family doctor service, including more GPs".