Idiopathic anaphylaxis: long-term follow-up, cost, and outlook

Economic burden of drug-induced anaphylaxis: what can we do better?

PURPOSE OF REVIEW

This systematic review evaluates published data related to the economic burden of drug-induced anaphylaxis (DIA) to understand preventive cost saving measures that could reduce the burden of these conditions.

RECENT FINDINGS

Although DIA has a relevant societal impact, there are limited and heterogenous available data related to its cost. Direct costs related to the management of acute phase of DIA was estimated by $529.6 to $3125, depending on the number of emergency room visits/hospitalizations, emergency kits and transports in ambulance. Direct costs of investigations of DIA varied from $288 to $2292.95 and the desensitization was estimated by $6796. Main variables for this were: personnel, allergy screening procedures, medical consumables and space cost. The mean indirect cost was based on a mean absenteeism of 3 days per DIA corresponding to $381.2.

SUMMARY

More than reviewing the published data, we were able to identify variables that, if correctly managed, can reduce the economic burden of DIA, such as adjusting the timing of referral and etiological diagnosis, identification of potential risk and/or co-factors, correct written recommendations to patients. The evidence presented highlights the need of optimization of healthcare patients to patients suffering from DIA.

The costs and consequences of omalizumab in uncontrolled asthma from a USA payer perspective

BACKGROUND

Omalizumab, an anti-immunoglobulin E antibody, reduces exacerbations and symptoms in uncontrolled allergic asthma. The study objective was to estimate the costs and consequences of omalizumab compared to usual care from a US payer perspective.

METHODS

We estimated payer costs, quality-adjusted survival (QALYs), and the incremental cost-effectiveness ratio (ICER) of omalizumab compared to usual care using a state-transition simulation model that included sensitivity analyses. Every 2 weeks, patients could transition between chronic asthma and exacerbation health states. The best available evidence informed the clinical and cost input estimates. Five years of omalizumab treatment followed by usual care was assumed to estimate a lifetime horizon. Omalizumab responders (60.5% of treated) were modeled as a separate scenario where nonresponders reverted back to usual care after 16 weeks of active treatment.

RESULTS

The mean lifetime discounted costs and QALYs were $83,400 and 13.87 for usual care and $174,500 and 14.19 for omalizumab plus usual care resulting in $287 200/QALY (95% interval: $219,300, $557, 900). The ICER was $172 300/QALY when comparing omalizumab to usual care in the responder scenario. One-way sensitivity analyses indicated that the results were sensitive to the difference in treatment-specific utilities for the chronic state, exacerbation-associated mortality, omalizumab price, exacerbation rates, and response definition.

CONCLUSIONS

The results suggest that adding omalizumab to usual care improves QALYs at an increase in direct medical costs. The cost-effectiveness of omalizumab is similar to other chronic disease biologics. The value increases when omalizumab response is used to guide long-term treatment.

The economic costs of severe anaphylaxis in France: an inquiry carried out by the Allergy Vigilance Network

BACKGROUND

The prevalence of severe anaphylaxis, between 1 and 3 per 10,000, has increased sharply over recent years, with a rate of lethality of 1%. The economic burden is unknown.

OBJECTIVE

The aim of this study was to estimate the economic costs of anaphylaxis, including direct costs of treatment, hospitalization, preventive and long-care measures, and the indirect cost: absenteeism.

METHODS

Analysis of 402 patients of anaphylaxis declared by 384 allergists was reported to the Allergy Vigilance Network. The global cost was estimated from the national data of hospital admissions: ICD-10 coding available for 2003, 2004 and 2005.

RESULTS

Three work/classroom days were lost per patient. Diagnosis required oral challenge with hospitalization in 18% of cases. The estimated mean total cost was 1895 euros for food- and drug-related anaphylaxis (5610 euros for the most severe), and 4053 euros for Hymenoptera anaphylaxis. National statistics recorded 2575 patients in 2005; 22% more than in 2003. The estimated annual cost was 4,789,500 euros. The possible reasons for this being an under-estimate include: data coming only from hospitalized patients, poor identification by medical teams unfamiliar with ICD-10 codes, peri-operative anaphylaxis being insufficiently declared, rush-immunotherapy and maintenance treatments for Hymenoptera anaphylaxis. Similarly, the extra cost of cow milk substitutes, as well as insurance costs where deaths are followed by litigation were not taken into account.

CONCLUSIONS

The mean cost of anaphylaxis was 1895-5610 euros in nonfatal patients. The prevalence was under-estimated because of many biases, leading to under-estimation of the national cost. Further studies would be necessary to evaluate the value of preventive strategies.

A current review of idiopathic anaphylaxis

PURPOSE OF REVIEW

Idiopathic anaphylaxis is a well established entity that can lead to unnecessary morbidity and costs if not diagnosed and managed properly. To ensure that more patients benefit from proper care, the medical community needs to be better informed of this rare disease.

RECENT FINDINGS

The classification and treatment of idiopathic anaphylaxis have been fine-tuned over the past 25 years without knowledge of the disease's underlying mechanism, despite much research dedicated towards this end. The observation that idiopathic anaphylaxis is a steroid-responsive disease has led to a more recent view that its underlying mechanism may be autoimmune in nature.

SUMMARY

Although the underlying pathogenesis of idiopathic anaphylaxis remains unknown, thousands of patients in the United States have been successfully treated with the currently recommended regimen of steroids and antihistamines. If diagnosed and treated properly, approximately 85% of patients will have a sustained remission after being tapered off corticosteroids.

Idiopathic anaphylaxis: a descriptive study of 81 patients in Spain

BACKGROUND

Few European groups have published data on series of patients with idiopathic anaphylaxis.

OBJECTIVE

Our aim was to report on our experience with this entity in Spain.

METHODS

We conducted a two-part investigation. The first part was a descriptive cross-sectional study of 81 patients with idiopathic anaphylaxis, diagnosed between January 1990 and December 1995 in the allergy unit of the General Hospital of Albacete in Albacete, Spain. The second prong was a prospective, longitudinal study that evaluated the activity of the condition.

RESULTS

Female patients constituted 68% of the study group with idiopathic anaphylaxis; the mean age of the 81 patients was 30.0 +/- 17.3 years. The number of episodes of idiopathic anaphylaxis during the year of greatest frequency varied widely (median, 2; range, 1 to 130). The duration also varied considerably, with a range of 0.03 to 300 months (median, 2 years). Most patients entered the study in remission, and 93% of these patients remained in remission throughout the followup period. Only 9% of the patients had vascular involvement. Our series of patients with idiopathic anaphylaxis had a notable prevalence of atopic diseases (48%), food allergy (20%), and episodes of anaphylaxis with an identifiable cause (15%). In addition, a high frequency (58%) of idiopathic urticaria was noted; the urticaria was acute in 62% of the affected patients.

CONCLUSIONS

Our series of patients with idiopathic anaphylaxis is similar to previously published series.