In many non-randomized, observational settings, treatment assignment mechanisms are opaque and researchers may not trust an assumption of conditional ignorability or the covariate-adjustment-based identification it allows. The Stability-Controlled Quasi-Experiment (SCQE, 2019) avoids this adjustment approach and makes no direct comparison between treated and untreated units. In settings with a change in the usage rate of some treatment of interest between successive cohorts, SCQE transforms an assumption about cohort-wide counterfactual outcome trends into estimates of the treatment's effect on those units that were impacted by the treatment change.