Attrition table. (1) Patients with CLL and/or SLL were identified using ICD-9-CM codes 204.1x and ICD-10-CM codes C91.1x and C83.0x, or evidence in unstructured documents of having been treated specifically for CLL/SLL. (2) Clinical encounters included patient visits from structured data (ECOG performance status, medication administrations, medication orders, telemedicine, vitals, and laboratory reports) and abstracted treatment information (classic cytogenetics, fluorescence in situ hybridization, immunoglobulin heavy chain, immunophenotyping, and oral medications). (3) For each patient, the study period extended from 6 months prior to the initiation of acalabrutinib or ibrutinib to the end of follow-up (the earliest of end of clinical activity, death, or end of data availability [ie, 28 February 2021]). (4) Concurrent antineoplastic treatments were defined based on antineoplastic treatments other than the list of anti-CD20 monoclonal antibodies, BCL2 antagonist, and PI3K inhibitors in supplemental Table 1 and Appendix 1. (5) See supplemental Table 1 and Appendix 2 for other malignancy diagnosis codes. (6) Patients may contribute to both the acalabrutinib and ibrutinib cohorts. FISH, fluorescence in situ hybridization; IGHV, immunoglobulin heavy chain; PI3K, phosphoinositide 3-kinase; 1L, first line; 2L, second line.