Table 1

MET-PREVENT trial schedule of events

Timepoint	Prescreening	Screen	Baseline	1 week (+3 days) after randomisation	1 month (+1 week) after randomisation	2 months (+1 week) after randomisation	3 months (+1 week) after randomisation	4 months ±2 weeks
Screening, consent and preallocation assessments
Brief study information sheet and invitation letter posted/given to patients identified via SarcNet Registry, older peoples medicine clinics, day units and rehabilitation facilities and GP practices	X
Telephone prescreening (verbal consent, demographics, SARC-F tool) for participants who send a positive reply slip	X
Patient information sheet posted to participants who pass prescreen	X
Informed written consent		X
Eligibility assessments (U&Es, LFTs, demographics, medical history, concomitant medication, adverse events, four metre walk speed, 5 x sit to stand time, grip strength)		X
Eligibility confirmation		X
Baseline assessments preallocation (blood glucose and HbA1c, height and weight, bioimpedance, AGE skin fluorescence, physical performance tests (SPPB, grip strength, six min walk), quality of life questionnaires (EQ5D5L, SF-36, Nottingham EADL), frailty screening questions (activity, exhaustion).			X
Allocation (randomisation)—following completion of assessments			X
Dispensing/posting trial medication			X
Biological samples
Blood and stool			X					X
Intervention
4 months supply of Metformin hydrochloride 500 mg tablets or matching placebo tablets
Follow-up
Confirm medication receipt, ability to open medication bottle, date of first dose				X
Safety blood tests (U&Es, LFTs, glucose, lactate)					X	X	X	X
Adverse event assessments		X	X	X	X	X	X	X
Concomitant Medications		X	X	X	X	X	X	X
Follow-up assessments (blood glucose and HbA1c, weight, bioimpedance, AGE skin fluorescence, physical performance tests (SPPB, grip strength, 6 min walk), quality of life questionnaires (EQ5D5L, SF-36, Nottingham EADL), frailty screening questions (activity, exhaustion).								X
Return of unused trial medication								X
Medication compliance, accountability								X

AGE, advanced glycosylation end; EADL, extended activities of daily living; EQ5D5L, EuroQoL 5 dimension 5 level; GP, general practices; HbA1c, glycated haemoglobin; LFTs, liver function tests; SARC-F, Strength, Assistance, Rise, Climb, Falls; SF-36, short form 36; SPPB, Short Physical Performance Battery; U&Es, creatinine and electrolytes.