Cost Analysis of Single-Dose Hepatitis B Revaccination Among Infants Born to Hepatitis B Surface Antigen-Positive Mothers and Not Responding to the Initial Vaccine Series

Objectives: Infants born to mothers who are hepatitis B surface antigen (HBsAg) positive are at risk for perinatal hepatitis B infection. As prevention, these infants receive a series of 3 or 4 doses of hepatitis B vaccine starting at birth and postvaccination serologic testing. Infants with antibody levels <10 mIU/mL are considered vaccine nonresponders and should be revaccinated. The objective of this cost analysis was to assess a single-dose revaccination strategy among infant nonresponders. Methods: We used a decision analytic tree to compare the costs of a single-dose revaccination strategy with the costs of a 3-dose revaccination strategy. The analysis consisted of 3 epidemiologic scenarios that varied levels of previous protection among infants indicated for revaccination. We assumed health outcomes in each strategy were the same, and we evaluated costs from the societal perspective using 2016 US dollars. We conducted sensitivity analyses on key variables, including the minimum required efficacy of a single revaccination dose. Results: In all analyses, the single-dose revaccination strategy was a lower-cost option than the 3-dose revaccination strategy. Under the assumption that all revaccination visits were previously unscheduled, single-dose revaccination reduced the cost per infant by $119.81 to $155.72 (depending on the scenario). Across all scenarios, the most conservative estimate for the threshold efficacy (the minimum efficacy required to result in a lower-cost option) value of single-dose revaccination was 67%. Conclusions: For infants who were born to HBsAg-positive mothers and who were not responding to the initial vaccine series, a single-dose revaccination strategy, compared with a 3-dose revaccination strategy, reduced costs across several scenarios. These results helped inform the Advisory Committee on Immunization Practices’ vote in February 2017 to recommend single-dose revaccination.

A two-degree-of-freedom ambulance stretcher suspension Part 1: System overview

Ambulance suspensions often give a poor ride, which may result in deterioration in the condition of ill or injured patients. Suspension of the ambulance stretcher itself is a lower cost option than a purpose- built ambulance suspension and may offer superior isolation of the patient from road-induced disturbances. This paper describes the development of a pneumatic stretcher suspension offering both pitch and heave isolation. Design and theoretical considerations are outlined, and preliminary performance figures reported. Subsequent parts of this paper will explore the dynamics of the system with pneumatic damping and report on the performance of the prototype suspension for a range of patient masses, damping levels and floor vibration inputs.