Fig 1.

(Top) Monthly average predicted risk of composite outcome of 30 day post-discharge non-elective readmission or mortality among all Kaiser Permanente Northern California (KPNC) hospital discharges, June 2010 to December 2018, for three groups (top). (Bottom) Monthly observed to expected rate of 30 day composite outcome for discharged patients with predicted low risk (<25%) or predicted medium and high risk (≥25%), June 2010 to December 2018. These subgroups correspond to the non-treated and intervention groups for the Transitions Program intervention, respectively. Vertical lines denote start of the implementation period, when first KPNC hospital went “live” with the Transitions Program (7 January 2016); and implementation complete, when last KPNC hospital went “live” (31 May 2017). All time series were smoothed using a three month moving average, and were seasonally adjusted using the X11 method⁴⁴