Fig. 1

Study population flowchart and proportional Venn diagrams showing overlap of criteria. Legend: Identification methods not mutually exclusive, events can belong to multiple groups. Implicit/Explicit ICD-9 sepsis defined based on taxonomies of infection and organ dysfunction codes proposed by Angus, et al. in addition to explicit sepsis codes. CMS ICD-9 sepsis defined based on list of codes used in the CMS measure. REGARDS-EHR defined as infection event meeting modified EHR criteria proposed by Rhee, et al.⁴ REGARDS-SOFA defined as infection event with ≥2 SOFA points across all organ systems (respiratory, cardiovascular, renal, hematological, hepatic, and neurological). REGARDS-qSOFA defined as infection events meeting ≥2 qSOFA criteria. Panel A) Population flowchart; Panel B) Venn diagram showing overlap between REGARDS-SOFA, REGARDS-qSOFA, and REGARDS-EHR; Panel C) Venn diagram showing overlap between Medicare-Implicit/Explicit and Medicare-CMS. Population for proportional Venn diagrams include all adjudicated hospitalizations, represented by the overall square area (Panel A: N = 1627 not meeting any classification; Panel B: N = 1677 not meeting either definition). REGARDS = REasons for Geographic and Racial Differences in Stroke study; A + B-C = participants with Medicare Parts A and B without Part C (managed care); SOFA = sepsis-related organ failure assessment; qSOFA = “quick” sepsis-related organ failure assessment; EHR = electronic health record; CMS = Centers for Medicare and Medicaid Services; ICD-9 = International Classification of Diseases, Ninth Revision