Optimising research investment by simulating and evaluating monitoring strategies to inform a trial: a simulation of liver fibrosis monitoring

The aim of the study was to investigate the development of evidence-based monitoring strategies in a population with progressive or recurrent disease. A simulation study of monitoring strategies using a new biomarker (ELF) for the detection of liver cirrhosis in people with known liver fibrosis was undertaken alongside a randomised controlled trial (ELUCIDATE). Existing data and expert opinion were used to estimate the progression of disease and the performance of repeat testing with ELF. Knowledge of the true disease status in addition to the observed test results for a cohort of simulated patients allowed various monitoring strategies to be implemented, evaluated and validated against trial data. Several monitoring strategies ranging in complexity were successfully modelled and compared regarding the timing of detection of disease, the duration of monitoring, and the predictive value of a positive test result. The results of sensitivity analysis showed the importance of accurate data to inform the simulation. Results of the simulation were similar to those from the trial. Monitoring data can be simulated and strategies compared given adequate knowledge of disease progression and test performance. Such exercises should be carried out to ensure optimal strategies are evaluated in trials thus reducing research waste. Monitoring data can be generated and monitoring strategies can be assessed if data is available on the monitoring test performance and the test variability. This work highlights the data necessary and the general method for evaluating the performance of monitoring strategies, allowing appropriate strategies to be selected for evaluation. Modelling work should be conducted prior to full scale investigation of monitoring strategies, allowing optimal monitoring strategies to be assessed.