A survey of 104 patients using a new NHS appointment booking service has found that the service is not being delivered as promised.

Choose and Book is a national service that aims to gives patients a choice of place, date and time for their first outpatient appointment in a hospital or clinic. Patients can book online or through GPs.

But 66 per cent of patients using Choose and Book at Hillingdon hospital said they were not given a choice of date for their outpatient appointment, according to the survey by University College London.

Two-thirds of patients also said they were not given a choice of appointment time, 86 per cent reported being given a choice of fewer than four hospitals, and 32 per cent reported not being given any choice of hospital.

Dr Henry Potts, of the UCL Centre for Health Informatics and Multiprofessional Education (CHIME), who oversaw the study, said it was clear patients were not experiencing the degree of choice that Choose and Book was designed to deliver.

"This may be only one hospital, with results taken in a transitional period, but we believe this could be typical of the national picture," he said.

"It is striking that nobody, up until to this point, has actually asked patients about their experience of the system."

Choose and Book is a key part of the £12.7bn National Programme for IT, and aimed to centre services around patients rather than vice-versa.

A spokesman for NHS connecting for health said: "We recognise when Choose and Book was launched in 2004 there were some initial teething problems. Today, with more than 10 million bookings, the University College London (UCL) study of 104 patients from a single hospital two years ago does not reflect the experience of most users."

Connecting for health pointed to a more recent National Patient Survey carried out in January 2008 which looked at 72,000 responses. It showed that progress is being made on choice of hospitals with 67 per cent of people going to the hospital they specifically chose.