Total Number of Cases that Result in Death
We estimated the number of deaths attributable to ABSSSI to be 1,868 in 2008, or 0.61 per 100,000 population. Applying this rate to 2011 population estimates yields a total of 1,923 deaths attributed to ABSSSI in 2011.
To calculate lost QALYs for patients who die from skin infections, we used the Compressed Mortality File. Using the mortality rate and age breakdowns for 2008 from the Compressed Mortality File, we estimated the total number of deaths by age group for the year 2011. Life expectancies by age were available from the National Vital Statistics Report (NVSR). To illustrate the calculation, there were an estimated 497 deaths caused by an ABSSSI among Americans aged 75-84 in 2011. The life expectancy for an 80-year-old is 8.8 years; thus, each person who died from an ABSSSI at that age was assumed to have lost 8.8 years of life. After matching the Compressed Mortality File age cohorts to an appropriate age in the NVSR data (usually the age in the middle of the cohort), we calculated total QALYs lost by the 75-84 age cohort as 4,374 (8.8 × 483). Summing lost QALYs across all ages yielded a total of 26,167 QALYs lost due to ABSSSI deaths in 2011.
To calculate VSL-based mortality costs, we multiplied the number of deaths in each age group by the VSL for those age groups. For ABSSSI, this resulted in $10.8 billion in mortality costs. The average per-patient VSL, weighted by the number of deaths by age, is $5.62 million.