Mountains of patient data collected by GPs could be used far more extensively by researchers in the next few years.
Observational studies using data routinely collected by practices will become more and more common, north London GP Dr Paul Wallace believes.
Dr Wallace also holds the post of deputy director for primary care at the NHS National Institute for Health Research's Clinical Research Network Co-ordinating Centre.
Increases in the quality of data being recorded by GPs and the amount of data available mean that observational studies are becoming more and more useful to researchers, he says.
The scope of such research is also set to expand as research networks grow to encompass data from more patient records.
At present, databases such as QResearch, The Health Improvement Network and the General Practice Research Database (GPRD), cover about 20 per cent of UK patient records.
'Work is currently underway to expand that and to make the use of medical records for research more widespread,'
Dr Wallace says. 'The results of pilot studies in this area are expected to come through in the next 18 months to two years.'
Dr Peter Meredith, of the University of Glasgow's division of cardiovascular and medical sciences, thinks prescribers in particular are likely to benefit from information from observational studies using GP practice data.
Speaking at the European Society for Hypertension (ESH) meeting in Oslo last month, he said rising costs of randomised controlled trials would mean fewer such trials were likely to be conducted in future.
Because drug regulators have become increasingly cautious, clinical trials now tend to concentrate on establishing safety profiles rather than examining efficacy, he told the conference.
The use of GP practice data could allow researchers to overcome these barriers, he said. 'Looking at registry data allows us to look at the real life situation,' he explained.
Rules defining who can take part in clinical trials limit the extent to which they can explore how drugs will affect patients they are likely to be prescribed to.
'In randomised trials, usually you have a big list of inclusion and exclusion criteria,' Professor Thomas MacDonald, head of the University of Dundee's medicines monitoring unit, told the ESH meeting.
He said patient populations in clinical trials could not reflect 'real life' patients.
Patients in trials tend to be about 20 years younger on average than those seen in clinical practice, and are healthier.
As well as allowing studies to look at treatment of higher risk patients, observational studies also enable researchers to look at combinations of treatments in a way that would not be possible in a randomised controlled study.
Professor MacDonald said that observational studies were often the only ethical way to look at how best to treat patients taking multiple drugs for a condition.
Randomising patients to receive a new drug or no treatment raised ethical issues, he pointed out. 'Observational studies fill this niche,' he said.
Although patient data in observational studies is anonymised, Dr Wallace said concerns about the confidentiality of information in research databases needed to be tackled.
At the end of last year, the MHRA warned that patient confidentiality could be compromised by researchers who were gaining unauthorised access to the GPRD.
Dr Wallace says that part of the solution to allaying concerns about how data would be used was to have buy-in from patients into the use of their data.
He sees the balance between participation in research and potential benefits as similar to that with blood donation.
'People's decision to donate blood is partly altruistic, but also about self-interest, as they might themselves benefit,' he said.
If the NHS can harness the untapped potential of the reams of data GP practices are sitting on and boost patient safety without compromising confidentiality, everyone's a winner.