Evidence Commensurate with Claim: Grading Seismic Resilience Studies for Service-Continuity Decisions

Seismic resilience studies increasingly inform municipal retrofit, restoration, and emergency-planning decisions, yet their results support claims of very different strength: a hospital that remains standing does not show that residents receive timely care. This critical review grades earthquake engineering and infrastructure studies, using an explicit codebook, by the strongest service-continuity claim their evidence supports. Most evidence stops at delivered service: requirements are rarely declared, rank stability substitutes for robustness, and outcomes are not observed after action. The weakness lies less in reporting than in reuse for decisions the studies were not designed to inform. We propose SCALE (Service-Continuity Assurance Ladder for Earthquake decisions), which ties continuity to non-compensatory requirements for each service, user group and time window; grades recommendations on an eight-level claim ladder; records residual doubts in a defeater register adapted from safety assurance cases; and links commitments to monitored triggers. Re-analysis of two published studies shows that 98.8% of the variation in modelled recovery time stems from workforce mobilisation rather than the ranked option, and that the preferred restoration strategy changes with the declared requirement. A municipal application in Cyprus identifies the evidence needed before a sheltering plan can be called adequate. SCALE allows Sendai Target D to be reported as service adequacy rather than disruption counts.