Exposure support map ==================== StatMedAnalysis | Original downloadable worksheet | 6 November 2026 Check whether each relevant covariate pattern permits the exposure comparisons being proposed. How to use this worksheet Define substantively important strata before examining model predictions. Summarize exposure counts and covariate ranges in each stratum. Separate structural absence of an exposure from sparse sampling. Record which target-population claims would require extrapolation beyond observed support. Save a working copy and keep the original blank version. Use public, hypothetical or aggregate information only; do not enter patient identifiers, credentials or confidential records. Keep source evidence in your approved project workspace. Mark unresolved text fields UNKNOWN or NOT REPORTED with a reason; never substitute zero for an unknown count. Project/version __________________ Prepared by role/date __________________ Working fields 1. Target population and contrast Response/evidence: _________________________________________________________ ___________________________________________________________________________ 2. Prespecified stratum definitions Response/evidence: _________________________________________________________ ___________________________________________________________________________ 3. Exposed and comparator counts Response/evidence: _________________________________________________________ ___________________________________________________________________________ 4. Covariate ranges by exposure Response/evidence: _________________________________________________________ ___________________________________________________________________________ 5. Structural restriction versus sparse data Response/evidence: _________________________________________________________ ___________________________________________________________________________ 6. Estimated propensity extremes if applicable Response/evidence: _________________________________________________________ ___________________________________________________________________________ 7. Affected target population fraction Response/evidence: _________________________________________________________ ___________________________________________________________________________ 8. Restriction or redesign and changed estimand Response/evidence: _________________________________________________________ ___________________________________________________________________________ Hypothetical worked case In a fictional prescribing cohort, no patient with a contraindication receives treatment A. A model prediction for A in that stratum extrapolates into a clinically impossible strategy; more regression terms do not repair that support gap. Decision rule and limitations Restrict or redefine the question when strategies are impossible in part of the population. State the resulting target population and examine sparse support separately from structural violations. Decision _______________________ Remaining uncertainty ____________________ Next action ____________________ Owner / review date ______________________ Independent check and discrepancy resolution _______________________________ Official method or reporting reference checked 6 November 2026 https://miguelhernan.org/whatifbook This is an original planning aid, not an official checklist, validated instrument, clinical recommendation or certificate of expert approval. Apply the referenced guidance to the specific design and record any additional requirements.