Table 2.

Measuring and understanding hospital mortality

Measure		Advantages	Disadvantages
Quantitative	Hospital level standardised mortality ratios (HSMR, SHMI etc)	bullReadily available for most hospitals	bullHighly dependent on coding bullLow rates may give false assurance bullLack clinical credibility bullDo not usually indicate problems in specific clinical areas
	Condition or pathway specific standardised mortality rates	bullReadily available for some conditions bullClinically credible bullRobust risk adjustment models bullCan be viewed alongside other process and outcome measures	bullNot available for all conditions bullValue limited to specific conditions bullNot usually integrated with other hospital measures of quality and safety
Qualitative	RCRR of all or a sample of deaths	bullCan inform wider learning by highlighting areas to focus quality improvement bullClinically credible	bullTime consuming bullExpensive bullSome decisions can be highly subjective bullUnstructured approaches unlikely to lead to useful learning
	Individual case-note review	bullHelpful for individual unexpected deaths, investigation of serious incidents etc bullCan be informed by data on other safety incidents, near misses etc	bullA risk that a whole system approach won't be taken if individual deaths are viewed in isolation

HSMR = hospital standardised mortality ratio; RCRR = retrospective case record review; SHMI = summary hospital mortality indicator.