Measurement device change assessment ==================================== StatMedAnalysis | Original downloadable worksheet | 6 November 2026 Assess comparability when an instrument, assay or device changes during collection. How to use this worksheet Record the old and new device versions, calibration procedures and measurement units. Plan an overlap or bridge assessment appropriate to the setting. Compare differences across the relevant measurement range rather than only the overall mean. Document whether a correction is justified and how its uncertainty is handled. 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. Device/assay versions and change date Response/evidence: _________________________________________________________ ___________________________________________________________________________ 2. Calibration and quality-control records Response/evidence: _________________________________________________________ ___________________________________________________________________________ 3. Overlap sample design Response/evidence: _________________________________________________________ ___________________________________________________________________________ 4. Measurement range and repeat structure Response/evidence: _________________________________________________________ ___________________________________________________________________________ 5. Systematic difference and variability Response/evidence: _________________________________________________________ ___________________________________________________________________________ 6. Correction model and evidence Response/evidence: _________________________________________________________ ___________________________________________________________________________ 7. Affected records and uncertainty Response/evidence: _________________________________________________________ ___________________________________________________________________________ 8. Pooling or stratification decision Response/evidence: _________________________________________________________ ___________________________________________________________________________ Hypothetical worked case A fictional assay replacement agrees near the midpoint but differs at high concentrations. A single average offset may not harmonize the full range; the bridge assessment must examine the relevant values. Decision rule and limitations Do not assume identical units guarantee comparable measurements. If bridging evidence is inadequate, preserve the device indicator and qualify comparisons across the change. Decision _______________________ Remaining uncertainty ____________________ Next action ____________________ Owner / review date ______________________ Independent check and discrepancy resolution _______________________________ Official method or reporting reference checked 6 November 2026 https://www.itl.nist.gov/div898/handbook/eda/eda.htm 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.