Mortality ratios were never designed to be the final word on the performance of a hospital. Give too much prominence to any one indicator and you get the gaming, media panic and kneejerk reactions which lead to bad management and policy decisions.

The first Dr Foster Hospital Guide was published at the start of the last decade to shock and brickbats from many. The measure employed − mortality ratios − was routinely dismissed as crude and irrelevant and even, by some campaigners, as threatening the NHS’s credibility by measuring its performance. This reaction was often a dangerous piece of self-interested displacement.

‘It is a pity the government review of the 14 worst performing trusts did not pick out the best for study and comparison’

Today, mortality ratios threaten to help topple an NHS chief executive and are quoted by the prime minister as the reason for a high-profile investigation. This is clearly a triumph for Sir Brian Jarman, father of the hospital standardised mortality ratio, and Dr Foster founder Tim Kelsey, the iconoclast now firmly ensconced in the establishment as the NHS Commissioning Board’s director for patients and information.

But the new power of mortality ratios carries dangers of its own.

It is a matter of record how Mid Staffordshire Foundation Trust’s hospital standardised mortality ratio was challenged by the organisation and strategic health authority. Some supporters of the trust claim it has been finally brought low partly because the data was awarded too great an importance.

Pernicious culture

Disputing the mortality rate alert proved to be a very poor decision − with terrible consequences. However, with the misleading, unqualified claim of 1,200 “deaths” at the trust becoming a media mantra, it is easy to see how those arguing for its continued survival − or indeed for a better understanding of mortality ratios − could become frustrated.

Mortality ratios, HSMRs or standardised hospital mortality indicators, can be excellent tools for highlighting areas for concern. They can also point to best practice − and it is a pity that the government review of the 14 worst performing trusts did not pick out the best for study and comparison, if only to stress how much excellent care is delivered in the NHS.

But mortality ratios are − and were never designed to be − the final word on the performance of a hospital. Give too much prominence to any one indicator and you get the gaming, media panic and kneejerk reactions which lead to bad management and policy decisions. In other words you get the kind of skewing of priorities that led to the pernicious culture operating at Mid Staffordshire.