Newborn screening for sickle cell disease can prevent deaths
Earlier diagnosis combined with prevention of infections as well as education of relatives increases life expectancy
After screening for sickle cell disease (SCD), also called sickle cell anaemia, with subsequent prevention of infections and education of professionals and relatives, fewer children are expected to die of SCD. On behalf of the Federal Joint Committee (G-BA), the Institute for Quality and Efficiency in Health Care (IQWiG) investigated whether systematic testing of newborns for SCD in Germany would be meaningful. The IQWiG researchers derive a hint of a benefit from a retrospective screening study with historical controls in children in Jamaica. Although the study results show a high risk of bias and are therefore subject to a certain degree of uncertainty, the observed difference between the intervention group and the control group is very large. This is because mortality decreases by a factor of 10: Up to the age of one year, 0.01% of children died in the group of children treated at an early stage; in contrast, 0.1% died in the group of untreated children. Stefan Lange, Deputy Director of IQWiG, explains: “Ongoing studies on the screening chain could not be identified. However, in view of the clear intervention effect in this retrospective study and its great importance for the particularly vulnerable group of infants and children, the benefit here can be clearly seen – even without randomized controlled trials (RCTs)."
Suitable test procedures for diagnosis
On the basis of studies on diagnostic accuracy, the IQWiG researchers examined the supplementary question of suitable diagnostic test procedures for SCD screening in Germany. The data available from these studies were insufficient to make reliable statements, but the positive predictive value (PPV) of individual studies indicates that test procedures with high specificity are indeed available: Of the babies identified by tandem mass spectrometry (MS/MS) and high performance liquid chromatography (HPLC), all were actually affected by SCD.
Deaths from organ failure and infections
SCD is hereditary and affects the red blood pigment haemoglobin, which transports oxygen in the blood: Genetic changes in haemoglobin cause the red blood cells to deform into a sickle shape and disintegrate faster than healthy cells. This leads to anaemia, poor blood circulation in the body, and blocked blood vessels. This causes chronic damage to important organs and the body's immune system, including fluid loss, oxygen deficiency, as well as fever and infections, which can lead to death. However, the symptoms do not appear until about the third month of life onwards.
Earlier diagnosis and early prevention of infections
Especially in the first years of life, children with SCD are very susceptible to life-threatening infections. Therefore, the aim of newborn screening for SCD is to identify and treat affected children as early as possible. The German guideline of the Consortium of the German Society for Paediatric Oncology and Haematology (GPOH) therefore not only recommends preventive behavioural measures for SCD treatment (such as informing parents about signs of infection and the appropriate reaction to acute complications), but also prevention of infections, including vaccinations, as well as lifelong structured long-term monitoring and treatment of affected patients.
A blood sample is sufficient
SCD can be diagnosed with a simple blood sample, just like the other target diseases that are already included in the German Newborn Screening Programme according to the Paediatric Directive of the G-BA: In the 36th to 72nd hour of life, a blood sample of the newborn is dripped onto filter paper cards and examined for various diseases. The SCD test could therefore easily be considered in the analysis. According to a survey based on routine data from children insured in the largest German statutory health insurance fund (AOK) and born in 2009 and 2010, early diagnosis of SCD in Germany currently takes place within the first six months after birth only in 15.4% of cases. In contrast, in the United States, England, France, Spain, the Netherlands and Belgium, newborn screening for SCD has been established for some time.
Few people affected in Germany
The incidence of SCD varies greatly from region to region and is linked to the spread of malaria, because people with SCD are less susceptible to malaria. Due to the lack of reliable data on the number of children born with SCD in Germany, only estimates are available, according to which at present, about 3000 people in Germany suffer from the disease. Projections suggest that about 200 babies with SCD are born each year in Germany. It can be assumed that SCD in Germany currently occurs predominantly in descendants from sub-Saharan Africa, the eastern Mediterranean region, the Middle East, and India.
Process of report production
The preliminary report on newborn screening for SCD was published by the Institute in April 2019. In the subsequent commenting procedure, four comments led to amendments to the final report, but they did not lead to a change in the conclusion. The written (German-language) comments are now also available on the Institute's website.