Literature selection
A total of 4917 studies was identified from the selected databases of
PubMed, Scopus and EBSCOHost and 696 studies were eliminated due to
duplication of titles. The remaining 4221 articles were screened, and
3980 articles were excluded because of irrelevant titles. Meanwhile, 44
articles involving other haemoglobin disorders such as sickle cell
disease (SCD) and myelodysplastic syndrome (MDS), 6 non-English
articles, 13 abstract-only articles, and 18 review articles were removed
after assessing the abstracts. The eligibility of the remaining 160
full-text articles was evaluated. In this process, 82 publications
without adherence/compliance measures, 5 studies focused on intervention
or healthcare providers’ services, and 53 articles that only evaluated
the determinants of chelation measure without comparing the outcomes
among the compliant and non-compliant population were removed. Finally,
only 20 articles were eligible for synthesis after the culling process.
The summary of the literature selection process in this review is shown
in Figure 1.