Specialist Advice Support for Management of Severe Hereditary Angioedema Attacks: A Multicenter Cluster-Randomized Controlled Trial

Ann Emerg Med. 2018 Aug;72(2):194-203.e1. doi: 10.1016/j.annemergmed.2018.01.053. Epub 2018 Mar 2.

Abstract

Study objective: Hereditary angioedema is a rare disease associated with unpredictable, recurrent attacks of potentially life-threatening edema. Management of severe attacks is currently suboptimal because emergency medical teams are often unaware of new specific treatments. The objective of this trial is to test whether a dedicated national telephone care-management strategy would reduce resource use during severe hereditary angioedema attacks.

Methods: We conducted a cluster-randomized multicenter prospective trial of patients with a documented diagnosis of hereditary angioedema (type I, II or FXII hereditary angioedema). Participants were enrolled between March 2013 and June 2014 at 8 participating reference centers. The randomized units were the reference centers (clusters). Patients in the intervention arm were given a national free telephone number to call in the event of a severe attack. Emergency physicians in the SOS-hereditary angiœdema (SOS-HAE) call center were trained to advise or prescribe specific treatments. The primary outcome was number of admissions for angioedema attacks. Economic evaluation was also performed.

Results: We included 100 patients in the SOS-HAE group and 100 in the control group. During the 2 years, there were 2,368 hereditary angioedema attacks among 169 patients (85%). Mean number of hospital admissions per patient in the 2-year period was significantly greater in the usual-practice group (mean 0.16 [range 0 to 2] versus 0.03 [range 0 to 1]); patient risk difference was significant: -0.13 (95% confidence interval -0.22 to -0.04; P=.02). Probabilistic sensitivity graphic analysis indicated a trend toward increased quality-adjusted life-years in the SOS-HAE group.

Conclusion: A national dedicated call center for management of severe hereditary angioedema attacks is associated with a decrease in hospital admissions and may be cost-effective if facilities and staff are available to deliver the intervention alongside existing services.

Trial registration: ClinicalTrials.gov NCT01679912.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Androgens / therapeutic use
  • Angioedemas, Hereditary / drug therapy*
  • Angioedemas, Hereditary / epidemiology*
  • Call Centers
  • Clinical Competence
  • Cluster Analysis
  • Emergency Service, Hospital
  • Female
  • Humans
  • Male
  • Middle Aged
  • Patient Admission / statistics & numerical data*
  • Progestins / therapeutic use
  • Prospective Studies
  • Quality-Adjusted Life Years
  • Tranexamic Acid / therapeutic use
  • Treatment Outcome

Substances

  • Androgens
  • Progestins
  • Tranexamic Acid

Associated data

  • ClinicalTrials.gov/NCT01679912