studysim: simulated medical studies for teaching

studysim is a jamovi module that simulates plausible datasets of medical studies. A student picks a clinical scenario, one of its outcomes, a study design that fits it, a sample size and some realism, and gets a dataset in a new jamovi window. A hidden answer key gives the true parameters and what crude and adjusted analyses of that design should find.

The Simulated study analysis: options on the left, study summary, data dictionary and descriptives on the right.

Why simulated studies

Real teaching datasets are few, and they never come with the truth. A simulated study does: confounders, mediators, effect modifiers and null variables are built in, so students can check whether their analysis recovers the effects, see why the crude estimate differs from the adjusted one, and what a design or a missing variable does to the answer. Every student can get a different dataset from the same assignment (a student key), and the teacher can regenerate any of them.

The menu

Analysis	What it does
Simulated study	scenario → outcome → design → dataset, data dictionary, descriptives, causal diagram, answer key
Compare designs	one scenario under several designs from the same population: estimates with 95% CI against the truth
Library	lists, checks, explores and exports the scenarios; reads custom libraries (YAML, Excel, JSON)
Derive scenario	estimates a scenario from a real dataset, to simulate studies like it

Teaching with studysim has worked exercises (confounding, mediation and the Table 2 fallacy, non-collapsibility, biases built on purpose, chance against bias), Analysing the data in jamovi says which analysis and module fit each design, and How it works describes the simulation model.

The Epidemiology guide is a short course that uses the simulator for its examples: measures and models, observational designs, trials and other designs, causal diagrams (confounders, mediators, colliders, how to build a DAG and choose the adjustment) and mediation (direct and indirect effects).

Install

Download the .jmo for your computer from the Releases page (x64 for Intel/AMD, arm64 for Apple silicon) and in jamovi go to Modules (⊕) → Sideload. It needs jamovi 28.4 or newer and no other package. The interface and the built-in scenarios are in English, Spanish and Catalan; jamovi’s language setting chooses.

The scenarios

The module ships with 65 scenarios across 21 clinical domains (dentistry and podiatry among them), most of them replicating a real study from its open data or its published tables, with several scenarios for every design. The scenario catalogue explains how they were made and lets you filter them by domain, design, outcome and teaching topic.