Table 3

General description of each eDCS in PRISMA

eDCS	General description
Patient information	Study number, year of birth and survival status including cause of death.
Informed consent	Status of informed consent (given or withdrawn), date of informed consent and individual patient decisions with regard to additional consent options.
Living situation	For example, independent or assisted living.
Current aneurysm state	For example, asymptomatic, acute or postoperative status.
First occurrence comorbidity	This eDCS contains a predefined list of comorbidities. Only if a participant has any of these comorbidities will this be registered, including the initial date of diagnosis. The list includes: hypertension, COPD, idiopathic lung fibrosis, peptic ulcer, diabetes mellitus, hypothyroidism and hyperthyroidism, hepatitis, portal hypertension, liver cirrhosis, any other liver disease, peripheral arterial disease, intracranial aneurysm, popliteal aneurysm, any other aneurysm, connective tissue disease, hypercholesterolaemia, carotid artery disease, renal dysfunction, renal disorders, ischaemic heart disease, heart failure, heart arrhythmia, heart valve disorders, any other cardiac disorder, haemiplegia or paraplegia, dementia and AIDS. Free-text descriptions can be provided for cases with an ‘any other’ comorbidity as mentioned above.
Family history	Registration of each known family member with (a history of) aortic aneurysmal disease and if known, at what age and whether there was an aortic rupture.
Social history	Marital status, employment status and educational status.
Initial aneurysm characteristics	Pathogenesis and type of AAA, status of AAA at time of inclusion, date of initial diagnosis and shape of AAA.
Comorbidity status	Status of a predefined list of comorbidities. This will be registered if this is known at the time of a visit to the department of vascular surgery. The list includes: COPD, diabetes mellitus (eg, dependency on insulin), peripheral arterial disease (eg, Fontaine classification), renal dysfunction, angina pectoris and heart failure.
Medication	This eDCS contains a predefined list of medications. Only pills and injections will be registered. If a medication is not included in the list, it will be added via a free-text description. Dosage will be registered for cardiovascular medications. The list includes: all types of cardiovascular medications, diabetes mellitus medication, corticosteroids, immunosuppressive medication and benzodiazepines.
Intoxications	Nicotine and alcohol use.
Physical examination	Body weight and patient length.
Blood test results	This eDCS contains a predefined list of blood tests, which will be registered if these have been carried out for clinical care. The list includes: creatinine, estimated glomerular filtration rate, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglycerides,
Surveillance	Date of surveillance visit, treatment plan including motivation.
Preoperative assessment	American Society of Anaesthesiologists physical status classification
AAA repair	Date of AAA repair, type of AAA repair and intraoperative complications.
Postoperative admission	Length of hospitalisation and intensive care hospitalisation
Postoperative follow-up	Date of postoperative follow-up visit and treatment plan including motivation.
Cardiovascular events	Myocardial infarction, cerebrovascular accident and thromboembolic events including dates.
Other surgical procedures	This eDCS contains a predefined list of certain procedures. The list includes: cardiac surgery, vascular surgery, abdominal and thoracic surgery and transplant surgery.
Malignancies	General type of malignancy, date of diagnosis and type of treatments.
AAA imaging	Date and type of AAA imaging. AAA status at time of imaging (eg, asymptomatic, acute or postoperative) and AAA diameter.
Complications	Complications after any AAA repair will be registered according to a predefined code list of the Dutch National Surgical Complications Registry, which was established by a committee of the Association of Surgeons in the Netherlands.

AAA, abdominal aortic aneurysm; COPD, chronic obstructive pulmonary disease; eDCS, electronic Data Capture Systems; PRISMA, Parelsnoer Repository for Information Specification, Modelling and Architecture.