Anaphylaxis Fatalities in Australia 1997 to 2013

Rationale The objective of this study was to determine whether Australian fatal anaphylaxis (FA) rates have increased in line with increases in hospital anaphylaxis admission rates. Methods Australian FA and hospital anaphylaxis admission rates were examined, using data derived from the Australian Institute of Health and Welfare and the Australian Bureau of Statistics over the period 1997-2013. Time trends were analyzed using Poisson regression with year (1997 to 2013) as a continuous predictor and total population as exposure variable. Results 323 cases of FA were reported in Australia between 1997 and 2013. Fatalities were attributed to; medication (52 cases), insect stings/tick bites (21 cases), food (23 cases), serum (3 cases) or unspecified cause (224 cases). Overall FA rates increased 1.8 fold from 0.05 (1997) to 0.09/100,000 (2013). FA increased 6.2% per year (95% CI: 3.8 to 8.6%, P<0.0001) and food-related FA increased 9.7% per year (95% CI: 0.25 to 20%, P=0.044). Total hospital anaphylaxis admissions (HAA) increased 3.9 fold, from 5.0 to 19.2/ 100,000 and food anaphylaxis admissions increased from 2.1 to 8.9 (4.2-fold) over the same period. HAA increased by 8.0% per year (95% CI: 7.8 to 8.3%, P<0.0001) and by 10.0% per year for food anaphylaxis admissions (95% CI: 9.9 to 10.6%, P<0.0001). Conclusions We report preliminary evidence of a rise in Australian FA (and food-related FA) rates comparable with increases in hospital admission rates. Our data contrast with recent UK and USA-based studies describing lower overall FA rates (0.047-0.069/100,000) and rising hospital anaphylaxis admission rates without a rise in fatalities.