Surveillance for Sickle Cell Disease — Sickle Cell Data Collection Program, Two States, 2004–2018

Abstract

Problem/Condition Sickle cell disease (SCD), an inherited blood disorder affecting an estimated 100,000 persons in the United States, is associated with multiple complications and reduced life expectancy. Complications of SCD can include anemia, debilitating acute and chronic pain, infection, acute chest syndrome, stroke, and progressive organ damage, including decreased cognitive function and renal failure. Early diagnosis, screenings and preventive interventions, and access to specialist health care can decrease illness and death. Population-based public health surveillance is critical to understanding the course and outcomes of SCD as well as the health care use, unmet health care needs, and gaps in essential services of the population affected by SCD. Period Covered 2004–2018. Description of the Program In 2015, CDC established the Sickle Cell Data Collection (SCDC) program to characterize the epidemiology of SCD in two states (California and Georgia). Previously, surveillance for SCD was conducted by two short-term projects: Registry and Surveillance System for Hemoglobinopathies (RuSH), which was conducted during 2010–2012 and included 2004–2008 data, and Public Health Research, Epidemiology, and Surveillance for Hemoglobinopathies (PHRESH), which was conducted during 2012–2014 and included 2004–2008 data. Both California and Georgia participated in RuSH and PHRESH, which guided the development of the SCDC methods and case definitions. SCDC is a population-based tracking system that uses comprehensive data linkages in state health systems. These linkages serve to synthesize and disseminate population-based, longitudinal data for persons identified with SCD from multiple sources using selected International Classification of Diseases, Ninth Revision, Clinical Modification, and Tenth Revision codes and laboratory results confirmed through state newborn screening (NBS) programs or clinic case reporting. Administrative and clinical data sources include state Medicaid and Children’s Health Insurance Program databases, death certificates, NBS programs, hospital discharge and emergency department records, and clinical records or case reports. Data from multiple sources and years are linked and deduplicated so that states can analyze and report on SCD population prevalence, demographic characteristics, health care access and use, and health outcomes. The SCD case definition is based on an algorithm that classifies cases with laboratory confirmation as confirmed cases and those with a reported clinical diagnosis or three or more diagnostic codes over a 5-year period from an administrative data source as probable cases. In 2019, nine states (Alabama, California, Georgia, Indiana, Michigan, Minnesota, North Carolina, Tennessee, and Virginia) were funded as part of an SCDC capacity-building initiative. The newly funded states developed strategies for SCD case identification and data linkage...

Pregnancy outcomes in women with sickle cell disease in California

“…Cases met at least one of the following criteria: (i) two different encounters with a SCD code in the principal position/diagnosis, (ii) one encounter with SCD as principal diagnosis and two more encounters with SCD as a secondary diagnosis, or (iii) three separate encounters with SCD in any secondary position. This algorithm combines stringent case definitions from our previous work 23–27 and broader criteria used by our colleagues 28–30 to arrive at similar number of SCD cases from hospital and ED discharge data sources reported in a recent external validation study 31 . Further, we only included SCD females of reproductive potential, which we defined as those between ages 10–45 years.…”

“…This algorithm combines stringent case definitions from our previous work [23][24][25][26][27] and broader criteria used by our colleagues [28][29][30] to arrive at similar number of SCD cases from hospital and ED discharge data sources reported in a recent external validation study. 31 Further, we only included SCD females of reproductive potential, which we defined as those between ages 10-45 years. We chose this age range because it (i) encompasses the average ages at menarche and menopause in the US, 5,32,33 and (ii) excludes expectant females at extremes of age, who may experience more pregnancy-related complications.…”

“…Lastly, we included the Distressed Communities Index (DCI), which compares the economic well-being of communities across the US using a weighted average of seven populations-based metrics derived from zip code level data, then normalizes that value into a single summary statistic (or DCI score) ranging from 0 to 100. 42 We assigned each woman's DCI score based on her residential zip code at time of delivery as reported in the PDD or EDU, then categorized them into 1 of 5 predefined economic groups: prosperous (0-20), comfortable (21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40), mid-tier (41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59)(60), at-risk (61-80), and distressed (81-100).…”

Improving Sickle Cell Disease Care

“…The disease is so named because red blood cells in people with this condition aren't round but are C-shaped like a sickle, due to abnormal hemoglobin. People who have SCD can experience episodes of pain and complications that may include infection, stroke, and acute chest syndrome, and many have a reduced life expectancy 1, 2. It's estimated that 100,000 people in the United States are living with SCD, but the exact number is unknown 1.…”

“…Although there's been a subsequent increase in funding and research of genetic therapies, there's an ongoing need to fund other SCD resources, such as systematic data collection. Currently, there's no national data collection system to determine prevalence and outcomes—or health care use and gaps in care—in people who have SCD, and many states also lack a comprehensive data collection process 2, 6. In 2015, the CDC established the Sickle Cell Data Collection (SCDC) program in two states, Georgia and California, to learn more about the number of people living with this disease, the way the condition affects them, and the type and quality of care they receive 2, 6.…”