The Summary Hospital-level Mortality Indicator (SHMI) is a score that reports on mortality rates at trust-level across the NHS in England, using a standard and transparent methodology. It is produced and published quarterly as an official statistic by NHS Digital and was first published in October 2011.
The SHMI is the ratio between the actual number of patients who die following hospitalisation at the trust and the number that would be expected to die on the basis of average England figures, given the characteristics of the patients treated there. In essence, therefore, SHMI is trying to do the same things as HSMR – with different variable factors taken in to account in calculating the scores. The key difference is that SHMI includes deaths following a patient’s discharge (within 30 days).
SHMI is published on a quarterly basis, usually six months in arrears. The chart below shows the Trust’s rolling 12-month SHMI data since the inception of the rating and reveals a trend of steady improvement.
One area for which SHMI does not make an adjustment is palliative care. The Trust is one of a handful of hospital groups in the NHS that has a hospice (most are run by charities). It is also unusual in having a seven-day a week palliative care service. Whilst both of these are important services for patients, they result in an increase in patients being coded as dying within our care compared to the national average – which may skew the Trust’s SHMI rating. For this reason, Dr Foster Intelligence also provides a SHMI rate adjusted for palliative care. The chart below provides detail of the Trust’s SHMI performance for recent years when adjusted in this way. The latter shows SHMI scores that better reflect the Trust’s performance and match other mortality indicators – such as HSMR and crude mortality, more closely.