Protocol for the Metformin Aneurysm Trial (MAT): a placebo-controlled randomised trial testing whether metformin reduces the risk of serious complications of abdominal aortic aneurysm

Table 1 Schedule of evaluations

Visit	Screening −10 to −6 weeks	Run-in^a −6 to 0 weeks	Randomisation 0 weeks	Follow-up^b
Visit	Screening −10 to −6 weeks	Run-in^a −6 to 0 weeks	Randomisation 0 weeks	3 monthly	6 monthly	Annually	Final^c
Time window for evaluation	N/A	+ 2 days	N/A	±14 days	±14 days	±14 days	N/A^c
Informed consent (prior to or at screening)	X
Assessment of eligibility	X
Demographics	X
Anthropometrics—height and weight	X					X^f	X^f
Behavioural—smoking	X
Medical history	X
Concomitant medications	X					X	X
AAA imaging (standard care)^h	X					X	X
Blood tests—creatinine, eGFR, HbA1c, CRP (if available), LDL-C (if available)^d	X					X^g	X^g
Blood sample for biomarker sub-study^e	X					X^e	X
QoL questionnaires: SF-36, AneurysmDQoL	X					X	X
Run-in medication dispensed	X
Randomisation			X
Study medication dispensed			X		X	X
Study medication adherence		X		X	X	X	X
AESI reporting		X		X	X	X	X
Serious adverse event reporting		X		X	X	X	X
Assessment of exploratory outcomes not classified as SAEs (diagnosis of cancer, diagnosis of diabetes, symptomatic gout)				X	X	X	X
Health economic assessment questions						X	X

^aParticipants will be contacted by telephone fortnightly during the 6-week run-in period
^bParticipants will be contacted every 3 months after randomisation
^cParticipants will undergo a final follow-up within 3 months of the date of the last adjudicated primary outcome event
^dIf blood tests are available from within 6 months prior to screening, no need to repeat tests at screening
^eOnly for participants who have consented to the biomarker sub-study. Samples will be collected at entry, at years 1 and 3, and at the final scheduled follow-up
^fWeight only
^geGFR only. If blood tests are available from within 3 months prior to annual follow-up/final follow-up, no need to repeat tests
^hIf imaging is available within 12 months of screening/annual follow-up, no need to repeat tests

ISSN: 1745-6215