Routine use of administrative data for safety and quality purposes--hospital mortality

Abstract

Worldwide, current practice is to report hospital mortality using the hospital standardised mortality ratio (HSMR). An HSMR is generated by comparing an indirectly standardised expected mortality rate against a hospital's observed mortality rate. A hospital's HSMR can be compared with the overall outcomes for all hospitals in a population, or with peer hospitals. HSMRs should be used as screening tools that alert institutions to the need for further investigation, rather than as definitive measures of the quality of care provided by individual hospitals. HSMRs are computed from existing hospital administrative data sources, which are fit for such a purpose. The addition of clinical or physiological data does not, at present, add to the discriminative powers of the risk adjustment models used to adjust HSMR values for differences in hospitals' casemixes. There has been concern that HSMRs may be too variable over time for individual values to be interpretable. A study of HSMR outcomes in Australian hospitals confirmed earlier reports of the stability of the measure. Considerable progress has been made with developing Australian HSMRs for use as routine measures to improve the safety and quality of Australian hospital care.