Blog

Research Methodology Insights

Practical guides on causal inference, study design, and statistical methods — written by researchers, for researchers.

Causal InferenceMSMTime-Varying Confounding

Marginal Structural Models: A Practical Guide for Clinical Researchers

How MSMs use stabilized inverse probability weights to handle time-varying confounders — the ones that change over time and are affected by prior treatment. Covers weight estimation, model fitting, clinical examples, and common pitfalls.

2026-04-02·17 min read
Causal InferenceDAGsCausal Framework

Structural Causal Models & DAGs: A Practical Guide for Clinical Researchers

The causal framework behind every method you use. Covers DAGs, d-separation, do-calculus, backdoor/frontdoor criteria, mediation analysis, and how to draw the graph that makes your analysis work.

2026-04-02·18 min read
Causal InferenceIPWPropensity Scores

Inverse Probability Weighting: When PSM Discards Your Data

Why IPW outperforms matching by keeping all patients — and how extreme weights, positivity violations, and wrong variance estimators break published analyses silently.

2026-04-02·15 min read
Causal InferenceMachine LearningHigh-Dimensional Data

Double Machine Learning: A Practical Guide for Clinical Researchers

How DML uses machine learning to estimate causal effects while controlling for high-dimensional confounders. Covers cross-fitting, Neyman orthogonality, clinical applications, and implementation in EconML.

2026-04-01·15 min read
Causal InferenceTarget Trial EmulationStudy Design

Target Trial Emulation: A Practical Guide for Clinical Researchers

The framework that bridges observational data and causal claims — by asking what RCT you wish you had. Covers protocol specification, time zero alignment, clone-censor-weight, immortal time bias, and reporting.

2026-03-30·16 min read
Causal InferenceRDDQuasi-Experimental

Regression Discontinuity Design: A Practical Guide for Clinical Researchers

RDD turns arbitrary thresholds into causal evidence. Covers sharp vs fuzzy designs, bandwidth selection, manipulation testing, clinical applications, and a complete reporting checklist.

2026-03-29·14 min read
Causal InferenceSynthetic ControlPolicy Evaluation

Synthetic Control Methods: Building Counterfactuals When DID Fails

How to construct a synthetic twin from donor pools when parallel trends don't hold. Covers SCM optimization, validation via placebo tests, modern extensions (ASCM, SDID), and common pitfalls.

2026-03-28·16 min read
Causal InferenceDIDPolicy Evaluation

Difference-in-Differences: A Practical Guide for Clinical Researchers

When and how to use DID in clinical research. Covers parallel trends, staggered adoption, common pitfalls, reporting checklist, and modern estimators.

2026-03-27·15 min read
Causal InferenceInstrumental VariablesUnmeasured Confounding

Instrumental Variables: When Observational Data Meets Unmeasured Confounding

When PSM and regression fail because of unmeasured confounding, IV methods offer a way forward. A practical guide covering instruments, LATE, Mendelian randomization, and the exclusion restriction.

2026-03-26·14 min read
Causal InferencePSMObservational Studies

Propensity Score Matching: A Practical Guide for Clinical Researchers

What PSM actually does, when it fails, and how to report it correctly. Written for researchers who want to use it — not just cite it.

2026-03-26·12 min read