Figure.

Process flow to determine sickle cell disease (SCD) case status of Children’s Healthcare of Atlanta (CHOA) patients (n = 1998) used to compare the performance of alternative case definitions to the Registry and Surveillance System for Hemoglobinopathies (RuSH) probable case definition, Atlanta, Georgia, 2016. The RuSH definition of a probable case required ≥2 SCD International Classification of Diseases, Ninth Revision (ICD-9-CM) codes¹⁶ on ≥2 separate health care encounters plus ≥1 hemoglobinopathy-associated complication, treatment, or procedure identified through ICD-9-CM codes, Current Procedural Terminology codes,¹⁷ or National Drug Codes¹⁸ but no laboratory-based disease confirmation available.