A national initiative to carry out mandatory screening of hospital patients for deep vein thrombosis has resulted in a "significant" reduction in death rates, experts in Birmingham have concluded.

A major study was carried out involving every single patient admitted to all 163 NHS hospital trusts in England between July 2010 and March 2012.

The team from the Quality and Outcomes Research Unit (QUORU) of University Hospitals Birmingham NHS Foundation Trust, led by Professor Domenico Pagano, sought to check the effectiveness of the venous thromboembolism (VTE) risk screening programme introduced into all NHS hospitals.

They have now concluded that if all trusts achieved the required quality standard, they could expect that 280 deaths from VTE would have been avoided among patients admitted to hospital for more than three days.

In addition, a further 150 deaths within 90 days of discharge could have been prevented among patients with hospital admissions of less than four days.

Prof Pagano will be presenting the findings on 16 September to the All-Party Parliamentary Thrombosis Group at Westminster.

The study, which is published in the respected health journal Heart, followed on from the Department of Health in England's decision in 2010 to introduce a quality incentive for NHS hospital trusts to screen at least 90 per cent of admitted patients for the risk of developing VTE.

Those hospitals which assessed at least 90% of patient admissions achieved the quality standard.

The study concluded that there was a "statistically significant reduction" in VTE deaths in hospitals achieving the risk assessment target, both for surgical and non surgical patients.

The published report makes clear that hospital associated VTE is a "potentially preventable" cause of death and disability, with the relative risk increasing more than 100 fold after hospital admissions for surgical procedures.

But it added that deaths from VTE are often sudden or are misdiagnosed pre-mortem and, therefore, prevention is a key strategy.

Analysis was based upon a series of monthly observations from each NHS Hospital Trust in England, and the association between outcomes and the achievement, or otherwise, of the VTE risk assessment target in that month.

The results showed that across the 21 months period of the study, on average, hospitals achieved the quality standard risk assessment 56 per cent of the time.

But closer analysis revealed a substantial improvement over the time period, from 51 per cent in the first month (July 2010) to 93 per cent in the final month (March 2012).

The report concluded: "Achieving the VTE risk assessment target was significantly associated with a reduction in death within 90 days of discharge both for primary VTE deaths and for VTE related deaths in patients with less than four days hospital stay.

"Our analyses provide convincing evidence of the effectiveness of the VTE risk screening programme in the English NHS.

"Taking the year 2011 as the basis for this estimation, if all trusts achieved the quality standard, we could expect as a result that 280 deaths from VTE (anywhere in the first 3 positions on the death certificate) would have been avoided among patients with admissions greater than 3 days.

"In addition we could expect that 150 deaths within 90 days of discharge would have been prevented among subjects with admissions less than 4 days. It is likely that this is an underestimate of the true number of VTE fatalities.

"In summary, this study demonstrates that a national quality initiative to increase the number of patients screened for VTE risk to at least 90%, linked to a financial penalty, has resulted in improvements in the outcome of death from VTE up to 90 days after hospital admission."

The complex statistical analysis in the study was conducted by a team led by Professor Nick Freemantle from University College London, who is also the director of biostatistics at QUORU.