Sickle cell disease (SCD) is a common single-gene disorder that affects three of every 1000 black newborns and approximately 50,000 persons in the United States.1 Children affected with SCD are at increased risk for severe morbidity (e.g., severe hemolytic anemia, splenic dysfunction, pain crises, and bacterial infections) and mortality, especially during the first 3 years of life.1,2 In 1993, California, Illinois, and New York collectively accounted for approximately 20% of all births to blacks. All three states offer universal newborn screening for hemoglobinopathies. To assess the effectiveness of newborn screening programs for SCD and for receipt of and compliance with early medical interventions (e.g., penicillin prophylaxis and pneumococcal vaccination and other vaccination patterns), a 3-year collaborative follow-up study was conducted from 1995 through 1998 in California, Illinois, and New York.3 This report summarizes the results of this study, which demonstrate the difficulty in retrospectively finding children who were screened at birth so that data for evaluating program effectiveness can be assessed.
The study comprised children born in 1992 and 1993 and in whom SCD was diagnosed during 1992-1993. Follow-up information about these children was ascertained through complementary surveys administered to parents and physicians of affected children. State health departments administered physician surveys, which were mailed to the child's last known provider. Parental surveys were administered by Battelle/Survey Research Associates, Inc., which conducted telephone interviews and, along with the respective health departments, made repeated attempts to locate the children.
During 1992-1993, SCD was diagnosed in 1042 children in California (265 cases), Illinois (254), and New York (523). Fourteen children (six in California, three in Illinois, and five in New York) died before the study began. Completed physician surveys were returned for 752 (72%) of the children (144 in California, 254 in Illinois, and 354 in New York). Parental surveys were completed for 252 (24%) children (87 in California, 52 in Illinois, and 113 in New York). When data from both surveys were merged, physician and parental surveys were completed for 184 (18%) children.
Among physician respondents, 575 (76%) reported providing antibiotic (penicillin) prophylaxis to their SCD patients; 253 (44%) patients complied with the prophylaxis antibiotic regimen. One hundred eighty-nine (25%) patients received pneumococcal vaccine, and 179 (24%) received at least the first dose of Haemophilus influenzae type b vaccine (Hib).
Among parental respondents, 111 (44%) were informed of SCD services available for their children, and 68 (27%) had used these services. Parents reported that 234 (93%) of their children with SCD regularly received penicillin prophylaxis; 189 (75%) received pneumococcal vaccine, and 164 (65%) received a full series of Hib.
Merged results from physician and parental surveys provided discrepant results regarding provision of and compliance with standard medical interventions for children with SCD. Although provision of penicillin prophylaxis was high in both surveys, physician-reported compliance for their patients' medical intervention was low.
K Pass, PhD, K Harris, MBA, Wadsworth Center, New York State Dept of Health. F Lorey, PhD, R Choi, Genetic Disease Br, California Dept of Health Svcs.'s Kling, MA, Div of Health Assessment and Screening, Illinois Dept of Public Health. Birth Defects and Genetic Diseases Br, Div of Birth Defects and Developmental Disabilities, and Office of Genetics and Disease Prevention, National Center for Environmental Health; and an EIS Officer, CDC.
Evaluations of pediatric outcomes after newborn screening are important to ensure provision and receipt of necessary services and to target high-risk groups for public health interventions. Data to assess program goals are incomplete for most disorders identified by newborn screening. The findings in this report demonstrate the difficulties in finding and contacting families retrospectively and the need for ongoing, prospective collection of follow-up information to identify gaps in delivering proper medical services and interventions.
In 1972, Congress passed the National Sickle Cell Anemia Control Act, and the first state newborn screening program for SCD was implemented in 1975.* However, states did not widely adopt newborn screening for SCD until 1986, when results of a randomized trial demonstrated that oral penicillin significantly reduced SCD-related morbidity and mortality in children.4 Results of this trial and statements from key organizations5- 7 resulted in adoption of newborn screening. In 2000, most states screen newborns for SCD.8
To reduce SCD-related morbidity and mortality, neonatal screening programs must be conducted as part of a comprehensive medical-care program.2,5- 7,9 Newborn screening programs identify children with SCD to allow early medical interventions, thereby preventing development of SCD-related complications and reducing morbidity and mortality. Standard preventive interventions for SCD include routine infant vaccination (e.g., pneumococcal vaccination) and prophylactic administration of penicillin.2,5- 7,9
The findings in this report are subject to at least three limitations. First, because of the poor contact rate, especially for parental surveys, results of this analysis are limited in generalizability and reflect the difficulty of ascertaining retrospective follow-up. Second, discrepant compliance rates should be interpreted with caution. The high compliance rate reported by parents was derived from a selected population (e.g., parents who were contacted successfully). However, the low compliance rate recorded by providers needs further investigation to ensure that they followed the children past age 2 years when the interventions actually were administered. Finally, ascertaining information retrospectively introduces possible recall bias.
A model program that allows program evaluation is the Cystic Fibrosis Foundation (CFF) Patient Registry, in which children diagnosed with cystic fibrosis are registered at health-care centers nationwide. The CFF Patient Registry prospectively collects annual epidemiologic, clinical, and laboratory data that can be used readily to assess the effectiveness of interventions and cystic fibrosis programs. SCD and other disorders identified by newborn screening would benefit from prospective evaluations of data related to morbidity, mortality, and receipt of preventive services. As the role of public health genetics programs expands beyond newborn screening, these types of long-term outcome data will be essential for developing effective programs and policies.
Update: Newborn Screening for Sickle Cell Disease—California, Illinois, and New York, 1998. JAMA. 2000;284(11):1373-1374. doi:10.1001/jama.284.11.1373