Hospitalization Rate Doubles for Food-related Anaphylaxis

New research into food-induced anaphylaxis concludes that hospitalization rates among American children roughly doubled between 2000 and 2009.

Journal of Allergy and Clinical Immunology

The study, which was published in the , estimated that the total number of hospitalizations for food induced anaphylaxis rose from 1,085 in 2000 to 2,253 in 2009.

Researchers from Brown and Harvard universities began by tapping the Healthcare Cost and Utilization Project Kids’ Inpatient Database, an all-payer source made up of more than 12 million randomly selected discharge files. They then narrowed the field to those files that contained a diagnosis code suggesting food-induced anaphylaxis (FIA) and extrapolated national figures from the numbers they found.

The sharp rise in anaphylaxis-related hospitalizations contrasted significantly with the overall pediatric hospitalization numbers, which fell slightly (though not significantly) from 1,812,000 to 1,793,000 during the study period. As a result, the number of FIA hospitalizations per 1,000 total hospitalizations grew from 0.60 in 2000 to 1.26 in 2009.

The study team also analyzed the trends for FIA hospitalizations among more than a dozen subgroups divided by age, sex, race, ethnicity, region of the country and type of hospital. Those analyses found significant increases in anaphylaxis-related hospitalizations for every single category but one — children younger than 2 years old.

Other factors, however, remained constant throughout the study period, factors such as average patient age (8.6 years in 2000 vs. 8.3 years in 2009) and gender ratios (56% male in 2000 and 55% male in 2009). What’s more, despite other research that suggests the prevalence of allergies is increasing particularly fast among black and Hispanic children, the new study found no significant differences in hospitalization growth rates for children of different races or ethnicities.

There were, however, appreciable financial. Total cost of care per patient more than tripled during the study period despite the fact that the average length of each hospital stay fell very slightly, from 2.3 days to 1.9 days.

The study did not try to explain why the cost of care rose so much faster than medical costs as a whole, nor did it speculate about the reason for very large differences in hospitalization rates in different regions of the country.

Overall, the highest rate was seen in the Northeast, with 2.25 FIA hospitalizations per 1,000 total hospitalizations, while the lowest was seen in the South, where there were 0.85 FIA hospitalizations per 1,000 total hospitalizations (P < .001).

“These data support a continued trend of increasing FIA hospitalizations among US children that had been reported in earlier studies of national health surveys (1998-2006), individual institutions (2001-2006), and statewide databases (1990-2006),” wrote the authors, who noted that their study also supports a seemingly contradictory work from the CDC.

“The Centers for Disease Control and Prevention reported that in the period 2005 to 2006, approximately 10,000 US children were hospitalized with a diagnosis of food allergy, tripling estimates from 1998. This estimate, however, included descriptive food allergy codes (i.e. food allergy not the primary admission reason). Excluding these descriptive codes, the annual number is similar to our 2006 estimate of approximately 2,000 US hospitalizations.”