Incorporating national disease burden in GBD estimates of haemoglobinopathies in Italy

The Global Burden of Disease (GBD) study represents an incredible source of information to quantify and understand the magnitude and impact of all conditions, including common and rare diseases, on patients’ quality of life, mortality, and morbidity. Emerging evidence suggests that detailed national studies are needed to inform, calibrate, and validate GBD estimates. This need is also supported by action on local GBD network, such as the Italian GBD network, cross-talking with the global GBD network. Thalassaemia and sickle cell disease are haemoglobin disorders distributed worldwide and represent an increasing public health burden. These inherited disorders tend to be highly prevalent in malaria-endemic regions across sub-Saharan Africa, the Middle East, and Southeast Asia, which tend to be data poor, and classified as rare diseases in Europe and North America, which are usually data rich. The change of classification terminology in transfusion-dependent thalassaemia and non-transfusion dependant thalassaemia represent a challenge when collecting epidemiological data required to correctly estimate the burden of such conditions. For example, Brousse and colleagues previously highlighted that the GBD 2021 study of sickle cell disease likely underestimated the number of patients with sickle cell disease in France and in the UK and overestimated the number of deaths for patients with sickle cell disease younger than 5 years.