Introduction
Thalassaemia is a hereditary disorder, characterised by abnormal globin chain synthesis in the haemoglobin molecules, affecting millions of people around the world and resulting in thousands of deaths annually [1]. Around 1.5% of the world’s population was found to be carriers of beta-thalassaemia [2]; with the prevalence estimated to range between 0.16 and 25 per 100,000 population in Europe, 4 per 100,000 population in North Africa, and 11-36 per 100,000 population in the Middle East [3].
Thalassaemia poses a high financial burden and a huge psychological burden on families, societies, and healthcare systems. Clinically, chronic blood transfusion is required for thalassaemia patients to attenuate anaemia and maintain a normal haemoglobin level. However, multiple episodes of blood transfusion to achieve these goals will have an effect on serum ferritin levels. Systemic iron overload can lead to iron accumulation in the heart, liver, spleen, and other organs, which can cause a variety of complications. The risk of serious iron overload complications is an alarming clinical concern, and properly utilized iron chelation therapy (ICT) is crucial to manage post-transfusional iron overload.
However, non-compliance with iron chelators persists as a major and enduring issue in transfusion-dependent thalassaemia patients. The most common obstacle in enhancing chelation compliance is patient-related, such as a lack of psychological willingness and belief in their ability in administering ICT, which is often due to failure in regulating their negative emotions. [4] The estimated mean rate of patients’ compliance of desferrioxamine (DFO) is often dissatisfactory, ranging from 59 to 78% [5]. Low compliance to iron chelation therapy jeopardises treatment effectiveness, resulting in significant morbidity and mortality, reducing patients’ health-related quality of life, as well as higher expenses to manage iron overload complications.
Many studies on thalassaemia and compliance to iron chelation have been conducted in a limited context around the world. Reddy et al. (2022) [6] systematically reviewed chelation adherence in the population of children and adolescents with thalassaemia, but not adults, while another study by Arian et al. (2019) [7] reviewed the health-related quality of life associated with thalassaemia patients but did not measure the ICT compliance among them. A review by Delea et al. (2007) [5] investigated the rate of compliance of desferrioxamine (DFO) and deferiprone (DFP) only without deferasirox (DFX) and the association between compliance and iron overload complications, focusing on health outcomes such as cardiac diseases, and diabetes using a small number of articles (as limited relevant studies were conducted at that time) [5]. Hence, there still exists some deficit in our knowledge on the impact of ICT therapy compliance on various clinical and patient-relevant outcomes in patients with thalassaemia. The objective of our current study was to further fill the gaps in measuring compliance rate in all ICT (DFO, DFP & DFX and the combination therapy), understanding the impact of chelation compliance on clinical outcomes and health-related quality of life in all populations of thalassaemia patients.
Methods
This systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement (PRISMA) to achieve high-quality and transparent research reporting. [8]