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BACKGROUND: Behavioural insights or 'nudge' theory suggests that non-directional interventions may be used to modify human behaviour. We have tested the hypothesis that the provision of the cost of common blood tests with their results may modify subsequent demand for blood assays. METHODS: The study design was a prospective controlled intervention study. The individual and annual institutional cost of full blood count (FBC), urea and electrolytes (U&E) and liver function test (LFT) blood assays were added to the electronic results system for inpatients at the intervention teaching hospital, but not the control hospital. RESULTS: In the 12 months after the intervention was implemented, demand for FBC dropped by 3% (95% confidence interval (CI) 1-5; p<0.001), U&E by 2% (95% CI 0-4; p=0.054) and there was no change in demand for LFT compared to the control institution. CONCLUSIONS: Providing cost feedback to clinicians for commonly used blood tests is a viable intervention that is associated with small reductions in demand for some, but not all blood assays. As this is an easily scalable approach, this has potential to enable efficient healthcare delivery, while also minimising the morbidity experienced by the patient.
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BACKGROUND & AIMS: Hepatic venous pressure gradient (HVPG) measurement is currently the only validated technique to accurately evaluate changes in portal pressure. In this study, we evaluate the use of non-contrast quantitative magnetic resonance imaging (MRI) as a surrogate measure of portal pressure. METHODS: Thirty patients undergoing HVPG measurement were prospectively recruited. MR parameters of longitudinal relaxation time (T1), perfusion of the liver and spleen (by arterial spin labelling), and blood flow in the portal, splanchnic and collateral circulation (by phase contrast MRI) were assessed. We estimated the liver stiffness measurement (LSM) and enhanced liver fibrosis (ELF) score. The correlation of all non-invasive parameters with HVPG was evaluated. RESULTS: The mean (range) HVPG of the patients was 9.8 (1-22) mmHg, and 14 patients (48%) had clinically significant portal hypertension (CSPH, HVPG ⩾10mmHg). Liver T1 relaxation time, splenic artery and superior mesenteric artery velocity correlated significantly with HVPG. Using multiple linear regression, liver T1 and splenic artery velocity remained as the two parameters in the multivariate model significantly associated with HVPG (R=0.90, p<0.001). This correlation was maintained in patients with CSPH (R=0.85, p<0.001). A validation cohort (n=10) showed this linear model provided a good prediction of HVPG. LSM and ELF score correlated significantly with HVPG in the whole population but the correlation was absent in CSPH. CONCLUSIONS: MR parameters related to both hepatic architecture and splanchnic haemodynamics correlate significantly with HVPG. This proposed model, confirmed in a validation cohort, could replace the invasive HVPG measurement. LAY SUMMARY: In patients with cirrhosis, the development and progression of portal hypertension is related to worse outcomes. However, the standard technique of assessing portal pressure is invasive and not widely used in clinical practice. Here, we have studied the use of non-invasive MRI in evaluating portal pressure. The MRI measures of liver architecture and blood flow in the splenic artery correlated well with portal pressure. Therefore, this non-invasive method can potentially be used to assess portal pressure in clinical trials and monitoring treatment in practice.