Table 1

Process evaluation measures based on the key driver diagram

Key driver	Intervention	Process measure
Primary drivers
Improve iron load status	Optimising patient assessment. Optimising standard management protocols. Optimising standardised documentation.	As listed below.
Improve endocrine management		As listed below.

Secondary drivers
Optimising patient assessment	Standardise echocardiographic assessment protocols. Training sessions for echo technicians. Introduction of T2* CMR. Anthropometric measurement. Performing Tanner staging. Conduct relevant endocrinological tests. Counselling.	The echocardiographic protocol has been described. This would be performed yearly if normal function; 6 monthly if dysfunction (EF <50%); the frequency may be altered if the patient was sick or undergoing emergent chelation due to severe symptoms or progression of cardiac symptoms (as determined by cardiologist BSH). Monthly visit by a paediatric cardiologist at each centre to observe imaging. 10% of images remotely monitored using WhatApp. T2* CMR initiated at an affordable price at AKUH; every 2 years if T2* >20 ms and the patient is compliant; annually if T2* <20 ms or if the patient is not compliant. Staff at all centres were trained by the paediatric endocrinologist using standardised calibrated machines. Quality check was done during the monthly visit on 10% of the measurements. Tanner staging was also taught by the paediatric endocrinologist to the staff at the peripheral centres. Quality check was performed on 10% of participants during the monthly visit. These were decided based on the I-CET guidelines in consultation with the paediatric endocrinologist. Lifestyle modification education focusing especially around chelation compliance, healthy diet and exercise as tolerated was provided at each peripheral centre. This was reinforced through CME performed by AKUH at these centres.
Optimising standard management protocols	CME courses. Multidisciplinary clinics and remote consultations.	Monthly meeting to disseminate knowledge of T2* CMR and evidence-based TDT management. Haematology, cardiology and endocrinology multidisciplinary clinic every month. Consultation and management of complicated patients at AKUH.
Optimising standardised documentation	Standardisation of chelation protocol. Standardised adverse event reporting.	Adequate chelation was defined according to the Thalassaemia International Federation guidelines. Standardised documentation for reporting of adverse events. Quality check on complete documentation was done on 10% of the study participants fortnightly.

AKUH, Aga Khan University Hospital; CME, Continuing Medical Education; echo, echocardiogram; I-CET, International Network on Endocrine Complications in Thalassemia; T2* CMR, T2* cardiac MRI; TDT, transfusion-dependent thalassaemia.