Trial ID	Intervention(s) (route, frequency, total dose/day)	Intervention(s) appropriate as applied in a clinical practice settinga	Comparator(s) (route, frequency, total dose/day)	Comparator(s) appropriate as applied in a clinical practice settinga
Alfawaz 2018	Metformin 500 mg twice a day plus standard advice on diet plus exercise	Yes	C1: intensive diet and exercise	Yes
			C2: diet plus exercise
PREVENT‐DM 2017	Metformin 850 mg daily for the first month, thereafter 850 mg twice daily. If side effects, then dose reduction. Titrated to the highest tolerable dose with a maximum of 850 mg three times a day	Yes	C1: intensive diet and physical activity	Yes
			C2: diet plus exercise
Zeng 2013	Metformin 38 mg once daily. Diet plus exercise (no details)	Yes	C1: diet plus exercise	Yes
			C2: pioglitazone 38 mg once daily Diet plus exercise
Zhao 2013	Metformin 500 mg twice daily Education plus behaviour interventions, including diet control and increased physical activity (at least 30 minutes per day and at least 5 days per week)	Yes	Education plus behaviour interventions, including diet control and increased physical activity (at least 30 minutes per day and at least 5 days per week)	Yes
Iqbal Hydrie 2012	Metformin 500 mg twice daily plus intensive diet and physical activity	Yes	C1: intensive diet plus physical activity	Yes
			C2: standard medical advice
Liao 2012	Metformin from 250 mg, three times daily, adjusting the dose according to blood glucose, with the maximum 1500 mg daily	Yes	Acarbose from 50 mg three times daily with meals, adjusting the dose according to blood glucose, with the maximum 300 mg daily	Yes
Ji 2011	Metformin 500 mg, three times daily, after meals. Standard advice on diet plus exercise	Yes	C1: Intesive diet plus exercise; based on individual dietary habits, calories are determined according to age, height, actual weight, activity intensity and season. Patients were given a low‐fat diet and a controlled diet. Patients were instructed to have a balanced diet and exercise (150 minutes per week).	Yes
			C2: diet plus exercise
Lu 2010	Metformin 250 mg three times daily, according to tolerance, gradually reaching the target dose of 500 mg three times daily Lectures and leaflets were given to inform the prognosis and hazards of pre‐diabetes, and scientific diet and exercise instructions were provided for each follow‐up to promote a healthy lifestyle	Yes	By giving lectures and sending out leaflets to inform the prognosis and hazards of pre‐diabetes, providing healthy diet and lifestyle guidance, referring to the dietary nutrition guidelines of China, and adjusting diet according to individual specific conditions to maintain a balanced nutritional status. The advice was: (1) variety of food, mainly cereals, with a combination of grains and grains; (2) eat more vegetables, fruits and potatoes; (3) daily intake of milk, beans and their preparation; (4) eat adequate amount of fish, poultry, eggs and lean meat; (5) reduce the amount of cooking oil, eat light diet with little salt, not too greasy and salty, including not too much smoke and animal oil food, daily adult salt to 6 g, eat less pickles, monosodium glutamate and other sodium‐containing food; (6) reasonable allocation of three meals, snacks should be appropriate. Reduce calorie intake to maintain the ideal weight. Patients with a BMI < 25kg/m2 were advised 30 Kcal/kg·day, with emphasis on alcohol and sugary soft drinks: patients with a BMI ≥ 25kg/m2 were encouraged to lose 0.5 g to 1.0 kg per month until ideal body weight. Initiate, encourage family members to care, supervise the completion of dietary plan. At each follow‐up, the participants were informed of dietary compliance. The exercise advice was as follows: (1) exercise prescription should consider the patient's individual factors such as gender, age, height, weight and living habits comprehensively; (2) principle of gradual progress and acting according to ability.The formulation of exercise prescription should be based on the patient's disease degree, physical condition to develop a long‐term plan, step by step, not subjective assumptions, eager for quick success and instant benefit. In the exercise prescription a clear purpose should be stated, and use the degree of realisation of this purpose to measure and modify the exercise prescription. Patients are required to engage in continuous aerobic exercise. Generally, after 30 minutes of exercise, blood glucose starts to supply energy to tissues, thus causing a drop in blood glucose. Moreover, studies have confirmed that the effect of moderate amount of exercise on blood glucose lasts for 12 months.17 hours, so people with diabetes should exercise at least once a day, no less than 30 minutes at a time. According to the principles and contents of exercise prescription, the exercise group should take appropriate physical activities and adopt various forms according to the specific conditions of each person, such as walking, jogging, playing ball games, aerobics, taijiquan, etc. It is required that the exercise program should be 1 exercise unit per day, lasting at least 30 minutes, and at least 5 days per week. At each follow‐up, participants were informed about exercise compliance and urged to stick to the prescribed exercise regimen.	Yes
BIGPRO1 2009	Metformin, 850 mg tablet twice a day; diet plus exercise	Yes	Identical placebo tablet given twice a day; diet plus exercise	Yes
Chen 2009	Metformin 750 mg, three times daily All patients received behaviour changing with reference to diet and exercise therapy in the diabetes guidelines of China	Yes	All patients received behaviour changing with reference to diet and exercise therapy in the diabetes guidelines of China.	Yes
Jin 2009	Metformin 1000 mg twice or three times daily. Diet plus exercise (no details)	Yes	C1: diet plus exercise (no details)	Yes
			C2: rosiglitazone 4 mg, orally, once daily. Diet plus exercise (no details)
Li 2009	Metformin 500 mg once daily plus diet and exercise	Yes	Individualised diet and exercise and education	Yes
Wang 2009	Metformin 250 mg twice daily, with or after meals. Plus standard advice on diet and exercise	Yes	Diet plus exercise	Yes
IDPP‐1 2006	I1: Metformin, 500 mg twice a day I2: Metformin, 500 mg twice a day plus intensive diet and physical activity	Yes	C1: intensive diet and exercise	Yes
			C2: standard care
Maji 2005	Metformin 500 mg once daily plus diet and physical activity	Yes	C1: intensive diet and physical activity	Yes
			C2: rosiglitazone 2 mg daily plus diet and physical activity
			C3: acarbose 25 mg twice daily plus diet and physical activity
Fang 2004	Metformin 375 mg to 750 mg three times a day	Yes	C1: acarbose 75 mg to 150 mg three times a day	Yes
			C2: intensive diet plus exercise
			C3: diet and physical activity
DPP/DPPOS 2002	Metformin 850 mg twice a day plus standard diet and lifestyle advice	Yes	C1: intensive diet plus exercise: consumption of a healthy low‐calorie, low‐fat diet and to engage in physical activity of moderate intensity (such as brisk walking) for at least 150 minutes/week	Yes
			C2: placebo tablets given twice a day plus standard diet and lifestyle advice
Lu 2002	Metformin 750 mg three times daily. Health education (not described, assumed to be standard care)	Yes	C1: health education (not described, assumed to be standard care)	Yes
			C2: diet instruction (every 6 months). Health education
			C3: fibre diet, fibre (Litesse) 6 g, twice daily, take with meal. Provide fibre once a month. Health education
Li 1999	Metformin, 250 mg three times a day	Yes	C1: placebo administered with the same schedule as metformin	Yes
Papoz 1978	Metformin 850 mg, twice daily plus placebo, twice daily; overweight participants were recommended calorie restriction	Yes	C1: glibenclamide 2.0 mg, orally, twice daily and placebo, orally, twice daily. Overweight participants were recommended calorie restriction	Yes
			C2: placebo, orally, twice daily; overweight participants were recommended calorie restriction
aThe term 'clinical practice setting' refers to the specification of the intervention/comparator as used in the course of a standard medical treatment (such as dose, dose escalation, dosing scheme, provision for contraindications and other important features) BMI: body mass index; C: comparator; I: intervention.