Senior National Health Service (NHS) managers and doctors believe delays to the NHS's £12.4 billion National Programme for IT (NPfIT) are putting patient safety at risk, a study published by the British Medical Journal has warned.

The top managers and clinicians, who supported NPfIT's aims, warned that continuing delays to the implementation of new patient administration systems were an unacceptable risk to patient safety.

The research is based on interviews with 25 senior managers and clinicians responsible for implementing the programme in four NHS hospitals. Interviews were conducted in two stages, 18 months apart, to compare progress and perceived challenges with the project over a period of time.

The first round of interviews revealed that financial deficits affecting many NHS trusts were a key concern along with delays in replacing patient administration systems, and poor communication between Connecting for Health, which runs NPfIT, and local managers.

Concern about the patient administration systems had increased 18 months on, with those surveyed warning that it posed a risk to patient safety. One respondent said: "Our path system is extremely out of date ... it's a huge risk to the trust that we're still carrying this path system."

Another warned: "There are a number of risks that are associated with our old system, some very serious risks."

Financial worries had also increased, with managers warning that they could not concentrate on implementing new IT systems because of competing financial priorities.

The research also showed little support for the Choose and Book system for booking outpatient appointments. One IT director said: "The software is not fit for purpose."

The study's authors said: "The staff we interviewed were unreservedly in favour of IT modernisation. But this support will quickly diminish unless more progress is achieved."