Table 3.

Matching characteristics and adjusted results of the included studies.

Studies	Matching Method	Adjusted Criteria (Confounder Exclusion)	Results
Sjostrom, et al., 2012 [23]	A matched control group of participants was created by an automatic matching program using 18 matching variables.	Adjusted for sex, age, history of stroke or MI, diabetes, insulin level, smoking history, BMI, waist circumference, hip circumference, systolic BP, total cholesterol, HDL cholesterol, triglycerides, lipid-lowering medication, antihypertensive medication.	aHR = 0.67; 95% CI 0.54–0.83; p < 0.001
Aminian, et al., 2019 [24]	Each surgical patient was matched with a propensity score by the nearest-neighbor method to 5 nonsurgical patients from a logistic regression model with a logit link function based on 7 a priori–identified potential confounders including the index date, age at index date, sex, BMI at index date (categorized as 30–34.9, 35–39.9, ≥40), location, insulin use, and presence of diabetes-related end-organ complications.	Adjusted for index date, sex, age, BMI, weight, race, annual income, smoking status, location of patients, medical history (hypertension, dyslipidemia, peripheral neuropathy, HF, coronary artery disease, chronic obstructive pulmonary disease, nephropathy, atrial fibrillation, peripheral artery disease, MI, cerebrovascular disease, ischemic stroke and dialysis).	aHR = 0.61; 95%CI 0.55–0.69; p < 0.001
Stenberg, et al., 2020 [25]	1:10 matched group of non-operated–on individuals, based on age, sex, and regional area of residence in Sweden.	Adjusted for duration of hypertension, comorbidities, and education.	aHR = 0.73; 95% CI 0.64–0.84; p < 0.001
Pirlet et al., 2020 [26]	Matched based on propensity score based on age, sex, BMI, weight, status of dyslipidemia, hypertension, diabetes, history of smoking, atrial fibrillation, HF, cancer, stroke, chronic obstructive pulmonary disease, chronic kidney disease, history of MI, history of ercutaneous coronary intervention, revascularization for MI, revascularization for unstable angina.	Adjusted from baseline characteristic not balanced in propensity score matching (History of MI and weight).	aHR = 0.64; 95% CI 0.41–0.99; p = 0.046
Moussa et al., 2020 [27]	Matched based on age, gender, and baseline BMI.	Adjusted for hypertension, hyperlipidaemia, diabetes, smoking, alcohol use, cocaine use, exercise and use of medications, such as beta-blockers, calcium channel blockers, angiotension converting enzyme inhibitors or angiotensin receptor blockers, statins, aspirin and hormone replacement therapy.	aHR = 0.410, 95% CI 0.274–0.615; p < 0.001
Hung et al., 2020 [28]	Matched 1:4 with patients in the surgical group by propensity-score matching, based on age and sex.	Adjusted for age, sex, Charlson Comorbidity Index (CCI), comorbidities (i.e., diabetes, hypertension, hyperlipidemia and gout).	aHR = 0.168; 95% CI 0.085–0.328; p < 0.001
Doumouras et al., 2021 [29]	Matched based on demographic status, history of smoking, history of diabetes mellitus, cardiac disease, stroke, hypertension, substance abuse, eating and mood disorder, liver and renal disease.	Adjusted for age, BMI, sex, immigrant status, income, rurality, diabetes status, overall cardiac history, stroke, chronic obstructive pulmonary disease, hypertension, sleep apnea, renal disease, smoking status, previous malignancy, substance abuse, self-harm, mood disorder, cancer screening (colon, breast, cervical) and health care use in previous year (family physician, hospital inpatient, emergency room visit, specialist visit).	aHR = 0.58; 95% CI 0.48–0.71; p < 0.001
Naslund et al., 2021 [30]	Matched 1:1 based on sex, age ( ± 3 years), year of MI ( ± 3 years), and BMI ( ± 3) to a control with MI registered in SWEDEHEART.	Adjusted for BMI, smoking, hypertension, chronic kidney disease, peripheral artery disease, HF, atrial fibrillation, chronic obstructive pulmonary disease, cancer disease within 3 years, and treatment with aspirin, P2Y12 receptor blockers, and statins.	aHR = 0.44; 95% CI 0.32–0.61
Yuan et al., 2021 [33]	Matched based on age, sex and BMI.	Adjusted for age and sex.	aHR = 0.62; 95% CI 0.44–0.88; p = 0.008
Batsis et al., 2007 [31]	Not matched	No adjustment	OR = 0.54; 95% CI 0.19–1.54
Nguyen et al., 2020 [32]	Not matched	Adjusted for gender, hospital region, all patients refined diagnosis related groups severity and risk of mortality, diabetes, hypertension, hyperlipidemia, chronic kidney disease, prior MI, peripheral arterial disease, chronic obstructive pulmonary disease, pulmonary arterial hypertension, atrial fibrillation and smoking.	aOR = 0.62; 95% CI 0.60–0.65; p < 0.001