SIMPREDICT (WORKING PAPER): info

What is SIMPREDICT

SIMPREDICT is a simulation-based tool for risk stratification model developers, emphasising the risks of conditions of low-to-moderate incidence, typically between 25 and 200 per 100,000 person-years. Incidence within this range represents a key challenge in identifying individuals with a sufficiently high risk that is clinically actionable.

Therefore, we focus on this clinically actionable test-positive group and provide reference numbers for the absolute risk characteristics of the test-positive group based on C-statistics, disease incidence, and the threshold of test positivity. The characteristics are TRs (test-positive rates), PPVs (positive predictive value i.e. the absolute risk of the test-positive group), and SRs (sensitivity rates, or the coverage % of disease cases in the test-positive group).

How to use

Via the TASK tab you can:

Estimate the absolute risks [Task 201]
Input the C-statistic to obtain the absolute risk characteristics (TRs, PPVs, and SRs) for diseases of different incidences

Minimal incidence required [Task 202]
Input the C-statistics and the test-positive threshold (based on PPV and SR) to obtain the minimal incidence required to identify such a group and the best PPV cut-off for diseases of difference incidence.

Minimal incidence required [Task 203]
Input the disease incidence and the test-positive threshold (based on PPV and SR) to obtain the minimal C-statistic required to identify such a group.

Result uncertainty (interquartile ranges IQRs) [Task 301]
Input the expected C-statistics, disease incidence, and the test-positive threshold to obtain the expected interquartile range (25-75 percentile) for different model-testing sample size.