The Chamberlain News

Dr Foster’s day out in the sun: the use and abuse of hospital mortality rates

He took his stats, therefore, to two journalists rather more committed to the idea that transparent, debateable research findings and more informed patients had key roles to play in improving health care. The outcomes were swift and far-reaching: the first of the now annual Dr Foster Good Hospital Guides, and Dr Foster Intelligence – a joint venture with the Department of Health, and today an internationally renowned provider of healthcare information – .

And the drivers of this growth have been HSMRs – which might surprise some of my 2001 students, who saw plenty of what they felt were potential weaknesses.

Yes, HSMRs are a purely statistical exercise – no inspections, interviews or case notes. Yes, change the indicators in the formula, and the ratios probably change too. Yes, they record only in-hospital deaths, and not even all of them. Yes, they surely could be manipulated – by discharging terminally ill patients into hospices, or (as three West Midlands trusts were later accused of doing) by stretching the ‘admitted for palliative care’ code and thereby raising the expected death rate.

To their credit, many hospitals’ response to a high HSMR has been to work with the Dr Foster team, to try to understand better the causes and thereby bring the ratio down. Walsall, for example, reduced its HSMR in five successive years, down to 103 by 2005/06.

There have also, though, been continuous criticisms of both HSMR methodology and interpretation – from health care professionals, the media and academia – particularly after 2007, when some of Dr Foster’s statistical ratios contradicted the inspection-based assessments of the Care Quality Commission.

There followed the first Francis Inquiry into the Mid Staffordshire NHS Foundation Trust, and with it the development and official approval of a new, more comprehensive mortality measure – the Summary Hospital-level Mortality Indicator (SHMI) – covering all, instead of most, in-hospital patient deaths, plus those occurring up to 30 days after discharge from hospital.

The two measures sound similar, and frequently they produce broadly similar results, as shown in the 2012 Dr Foster Guide. Birmingham’s HSMR is 112, its SHMI 105; Sandwell & West Birmingham 99 and 97; Coventry & Warwickshire 103 and 107; Walsall 117 and 113; Royal Wolverhampton 100 and 103 – .

But they can differ significantly – and did for several of the 14 trusts investigated in the Keogh Report. You might think that the Government, having finally found in SHMIs a more comprehensive and reliable mortality measure than HSMRs, would use it to select the hospital trusts it wished to have investigated.

Wrong! The supposedly failing trusts were picked because of being high ‘outliers’ for two consecutive years (2010/11 and 2011/12) on either of the two measures. So Tameside and Basildon/Thurrock were included apparently because of their higher than expected SHMIs, but Burton and Sherwood because of higher than expected HSMRs.

We’re into circumstantial evidence here. But, suppose you were a Government keen to rubbish Labour’s NHS record and frighten patients and electors into viewing further privatisation more favourably. It surely wouldn’t seem a bad tactic to maximise the number of allegedly failing ‘killer’ hospitals – 14 is nearly one in 10 of England’s acute hospital trusts – and feed the media scare stories about thousands of ‘avoidable’ deaths. Or has my imagination run away with me?