Outcome ascertainment comparability =================================== StatMedAnalysis | Original downloadable worksheet | 6 November 2026 Check whether groups have equivalent opportunities for an outcome to be detected. How to use this worksheet Map how an event becomes a recorded outcome from symptoms through contact, testing and coding. Compare visit frequency, testing triggers and adjudication across groups. Separate differences in underlying outcome risk from differences in detection opportunity. Record feasible design or analysis responses. 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. Clinical outcome construct Response/evidence: _________________________________________________________ ___________________________________________________________________________ 2. Data-source operational rule Response/evidence: _________________________________________________________ ___________________________________________________________________________ 3. Contact or testing pathway Response/evidence: _________________________________________________________ ___________________________________________________________________________ 4. Observation intensity by group Response/evidence: _________________________________________________________ ___________________________________________________________________________ 5. Blinding or adjudication procedure Response/evidence: _________________________________________________________ ___________________________________________________________________________ 6. Unrecorded events and linkage coverage Response/evidence: _________________________________________________________ ___________________________________________________________________________ 7. Differential detection concern Response/evidence: _________________________________________________________ ___________________________________________________________________________ 8. Response and residual uncertainty Response/evidence: _________________________________________________________ ___________________________________________________________________________ Hypothetical worked case In a fictional cohort, treated patients receive monthly laboratory testing while comparators are tested annually. More recorded abnormalities may reflect the observation schedule as well as underlying biology. Decision rule and limitations Flag materially unequal ascertainment before interpreting group differences. Covariate adjustment cannot be assumed to remove an unmeasured detection process. 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.