Health chiefs at a hospital trust in north Essex say they are seeing a decrease in the number of patients dying despite a new report that singles it out for persistently high death rates.

According to analysis from the Health and Social Care Information Centre (HSCIC), published yesterday, between July 2011 and June 2013 the Colchester Hospital University NHS Foundation Trust had a higher than expected ratio of patient deaths.

Last year HSCIC also named the trust, which runs Colchester General Hospital and Essex County Hospital, among five trusts that had high death rates over a different two-year period. The findings prompted the high-profile Keogh Review, which investigated the care and treatment of patients at the hospitals. HSCIC bases its findings on Summary Hospital-level Mortality Indicator (SHMI) data, which compares the actual number of patients to die following hospitalisation at a particular trust with the number that would be expected to die, based upon average England figures. It considers deaths taking place during a stay at a trust and also within 30 days of a patient being discharged.

“The SHMI, combined with other indicators provides a very useful insight, which should prompt trusts to undertake a further, more detailed examination of their services, but should not be seen as a definitive judgement” said HSCIC chairman Kingsley Manning.

But the trust says there are other ways of measuring death rates, which show it in line with national averages, and it points to figures that show less people are dying at their hospitals year-on-year.

A spokesman for Colchester Hospital University NHS Foundation Trust said: “We take the issue of SHMI extremely serious and because it includes deaths within 30 days of discharge from hospital continue to work closely with partner organisations, such as North East Essex Clinical Commissioning Group, to make improvements. There has been a small reduction in this particular mortality indicator.

“The other main mortality measure, HSMR – Hospital Standardised Mortality Ratio – measures only deaths that occur in our hospitals and for the past few years our HSMR score has been ‘within the expected range’.

He added: “The number of deaths at Colchester General Hospital and Essex County Hospital continues to fall year-on-year even though we are seeing more patients. For example, there were 103 few deaths in 2013 than 2012, a reduction of 7%. We remain committed to take every possible step to prevent avoidable deaths.”

Earlier this week a quality and performance report on Colchester Hospital NHS Trust presented to the North East Essex Clinical Commissioning Group board also indicated an improvement in death rates.

It read: “The Summary Hospital-Level Mortality Index (SHMI) for the year to end March 2013 has fallen to 115.51 from 118.32 to end Dec 2012. The alternative measure of mortality, Hospital Standardised Mortality Rate (HSMR), continues to show a downward trend between April and October 2013. Given the downward trend in both indicators, it is possible that this represents a new trend of reducing mortality rates in north east Essex.”

It said the reductions may reflect improvements in documentation, more consultants being involved in cases in accident and emergency cases and improvements in the provision of end of life care in the community.