Survival risk ratios for ICD-10-AM injury diagnosis classifications for all ages

The survival risk ratios (SRRs) were calculated using linked
hospitalisation and mortality data from New South Wales (NSW), Australia. Hospital admissions was obtained from the NSW
Ministry of Health and included all injury-related admissions identified using
a principal diagnosis of injury (ICD-10-AM: S00-T89) during 1 January 2010 to
30 June 2014. Mortality data was
obtained from the NSW Registry of Births, Deaths and Marriages from 1 January
2010 to 31 March 2015. Hospitalisation
and mortality data were probabilistic linked by the Centre for Health Record
Linkage (CHeReL). NSW covers an area of 800,628km2 with a population
of around 7.7 million.

The SRRs were calculated for each injury diagnosis. A SRR
represents the ratio of the number of individuals with each injury diagnosis
who did not die to the total number of individuals with the injury diagnosis. The SRRs can be used to estimate injury
severity (i.e. the International Classification of Injury Severity Score:
ICISS). The ICISS is calculated by
applying the SRRs to each injury diagnosis code in your data. There are
two methods commonly used to then estimate ICISS values: (i)
multiplicative-injury ICISS where ICISS is the product of all SRRs for each of
the individual’s injuries; and (ii) single worst-injury, where ICISS only
includes the worst-injury (i.e. the injury diagnosis with the lowest SRR) as
the single worst-injury.