Table 2.

Measuring and understanding hospital mortality

Measure		Advantages	Disadvantages
Quantitative	Hospital level standardised mortality ratios (HSMR, SHMI etc)	Readily available for most hospitals	Highly dependent on coding Low rates may give false assurance Lack clinical credibility Do not usually indicate problems in specific clinical areas
	Condition or pathway specific standardised mortality rates	Readily available for some conditions Clinically credible Robust risk adjustment models Can be viewed alongside other process and outcome measures	Not available for all conditions Value limited to specific conditions Not usually integrated with other hospital measures of quality and safety
Qualitative	RCRR of all or a sample of deaths	Can inform wider learning by highlighting areas to focus quality improvement Clinically credible	Time consuming Expensive Some decisions can be highly subjective Unstructured approaches unlikely to lead to useful learning
	Individual case-note review	Helpful for individual unexpected deaths, investigation of serious incidents etc Can be informed by data on other safety incidents, near misses etc	A 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.