Table 1. Summary of papers found by literature search that meet the inclusion criteria.

Study author	Type of study	Total number of patients	Surgery	Follow-up time	Comparison	Aspirin dose	Outcome measure
Raphael et al, 2014 15	Retrospective study	28,923	Total joint arthroplasty	90 d	Aspirin vs. variable dose warfarin	325 mg BD	Symptomatic VTE, complications, mortality.
Jiang et al, 2014 16	RCT	120	Total knee arthroplasty	Unknown	Aspirin vs. LMWH/ rivaroxaban	Unknown	Incidence of VTE
Zou et al, 2014 17	RCT	324	Total knee arthroplasty	Unknown	Aspirin vs. LMWH vs. rivaroxaban	100 mg/day	Incidence of DVT, complications
Na et al, 2015 18	Retrospective study	328	Total knee arthroplasty	3 mo	Aspirin vs. LMWH and aspirin	100 mg/d	Incidence of DVT or PE, complications
Asopa et al, 2015 19	Retrospective study	9,035	Hip and knee arthroplasty	6 wk	n/a	300 mg/d only given on discharge	Incidence of symptomatic VTE
Pow and Vale, 2015 20	Retrospective study	402	Total hip and knee arthroplasty	Unknown	Aspirin vs. anticoagulants in hospital and discharge	Unknown	VTE prophylaxis prescribing, incidence of VTE
Ogonda et al, 2016 21	Retrospective study	11,459	Total hip, total knee, and unicompartmental knee arthroplasty	3 mo	Aspirin vs. National Joint Registry rates	150 mg/d	Incidence of DVT and PE, mortality
Yhim et al, 2017 22	Retrospective study	306,912	Total hip and knee arthroplasty	3 mo	Aspirin vs. anticoagulants and no thromboprophylaxis	Unknown	Incidence of VTE, prescription rates

Abbreviations: BD, twice a day; DVT, deep vein thrombosis; LMWH, low molecular weight heparin; PE, pulmonary embolism; RCT, randomized control trial; VTE, venous thromboembolism.