A UK national audit of hereditary and acquired angioedema.

Hereditary angioedema (HAE) and acquired angioedema (AAE) are rare life-threatening conditions caused by deficiency of C1 inhibitor (C1INH). Both are characterized by recurrent unpredictable episodes of mucosal swelling involving three main areas: the skin, gastrointestinal tract and larynx. Swelling in the gastrointestinal tract results in abdominal pain and vomiting, while swelling in the larynx may be fatal. There are limited UK data on these patients to help improve practice and understand more clearly the burden of disease. An audit tool was designed, informed by the published UK consensus document and clinical practice, and sent to clinicians involved in the care of HAE patients through a number of national organizations. Data sets on 376 patients were received from 14 centres in England, Scotland and Wales. There were 55 deaths from HAE in 33 families, emphasizing the potentially lethal nature of this disease. These data also show that there is a significant diagnostic delay of on average 10 years for type I HAE, 18 years for type II HAE and 5 years for AAE. For HAE the average annual frequency of swellings per patient affecting the periphery was eight, abdomen 5 and airway 0·5, with wide individual variation. The impact on quality of life was rated as moderate or severe by 37% of adult patients. The audit has helped to define the burden of disease in the UK and has aided planning new treatments for UK patients.

Descriptive epidemiology of hereditary angioedema hospitalizations in the United States, 2004-2007.

Hereditary angioedema (HAE) is a rare inherited disorder of complement factor C1 inhibitor. There are ∼6000 HAE cases in the United States, nearly one-half of whom suffer a monthly exacerbation. Little is known about hospital use patterns by patients with HAE attacks in the United States. This study was designed to examine burden, epidemiology, and outcomes of hospitalizations among HAE patients. We evaluated epidemiology, resource use, and discharge destinations of HAE (ICD-9-CM code 277.6) hospitalizations within the NIS, part of Agency's for Healthcare Research and Quality Healthcare Costs and Utilization Project in 2004 through 2007. There were 10,125 hospitalizations with HAE, of which 3216 (31.8%) had HAE as the principal diagnosis (HAE-PD). Two-thirds of all HAE hospitalizations were among women, and 60% were white. Hypertension was the most common comorbidity (26.9%, all HAE, and 28.0%, HAE-PD). Mortality was 1.4% in HAE and 0.3% in the HAE-PD group. Mean hospital length of stay (3.7, 95% CI 3.0-4.4 days vs. 5.0, 95% CI 4.6-5.4 days) and costs ($4,760, 95% CI $3,612-$5,907 vs. $8,383, 95% CI $7,432-$9,334) were lower in HAE-PD than in the HAE cohort. Although >80% in each group were discharged home routinely, 15.9% of HAE and 4.9% of HAE-PD required either home health care or a transfer to another short-term hospital or a skilled nursing facility. HAE hospitalization volume is substantial. Because diagnostic uncertainty is likely, HAE and its related resource use may be underestimated. HAE prevention strategies need to be examined in the context of these outcomes.