Pharmacoeconomics: Open Access

Background: Most Health Technology Appraisals (HTA) model survival data using a conventional set of six parametric distributions. Alternative and potentially useful distributions exist and could also be exploited. Rayleigh 2 parameter (R2P) and Weibull models are both defined with two parameters and exhibit monotonic hazard; the Rayleigh model is relatively unused in HTA and should not be regarded as just a special case of the Weibull model.

Aim: To explore circumstances where the predictions from R2P and Weibull models may differ or coincide.

Method: Stata software was used to model sample survival data with R2P and Weibull models and to compare the predicted hazard and survival from each parametric.

Results: R2P models generate different predictions to Weibull models except in the special case where the Weibull shape parameter equals or closely approaches two and the Weibull hazard prediction is linearly increasing. When compared to Weibull models R2P models may generate a better fit to observed data according to conventionally used indicators of goodness of fit.

Conclusion: Rayleigh modelling of survival warrants inclusion in the survival modelling undertaken in Health Technology Appraisals.

In 15–35% of cases, depending on the specifics of the traumatic event and the subject's subjective experience, a scenario or stressful occurrence that is extraordinarily threatening or catastrophic and could result in clear distress symptoms in the majority of people "causes" PTSD.

Background: Bronchoscopy procedures are conventionally associated with complex supporting processes, large capital investments and inevitable repairs. Cost-comparison analysis with the single-use bronchoscope Ambu® aScope™4 Broncho within a UK intensive care unit have never been done before.

Materials and Methods: We conducted a cost-comparison analysis of reusable vs single-use bronchoscopes within the intensive care unit of the Royal Infirmary of Edinburgh via a micro-costing method.

Results: At the current split between reusable and single-use bronchoscopes, the incremental cost of using single-use vs. reusable bronchoscopes was £111. In a binary setup with either reusable or single-use bronchoscopes, the incremental procedure cost was£90. Singleuse bronchoscopes were cost-minimising up to 75 annual procedures per reusable bronchoscope. When including a 0.72% and 2.8% risk of cross-infection the incremental cost of was £159 and £352.

Conclusion: Single-use is cost-effective compared with reusable bronchoscopes within the ICU setting.