Table 1

Primary prevention of thrombosis with low-dose aspirin (LDA) in individuals with high-risk antiphospholipid antibody (aPL) profile, patients with systemic lupus erythematosus (SLE) and non-pregnant women with a history of obstetric antiphospholipid syndrome (APS) only

ReferenceDesignComparisonInterventionControlNumber of patients, interventionNumber of patients, controlEvents, interventionEvents, controlRelative effect (95% CI)Study quality
Asymptomatic individuals with high-risk aPL profile
Arnaud et al 20147Meta-analysisDirectLDANo LDA treatment22923118 (7.8%)31 (13.4%)OR 0.50 (0.25 to 0.99)
Arnaud et al 20158Meta-analysisDirectLDANo LDA treatment66105NANAHR 0.46 (0.17 to 1.20)
Mustonen et al 20149Prospective cohortDirectLDANo LDA treatment45741 (2.2%)8 (10.8%)OR 0.19 (0.02 to 1.56)Intermediate quality
Patients with SLE and high-risk aPL profile
Arnaud et al 20147Meta-analysisDirectLDANo LDA treatment26117924 (9.2%)30 (16.7%)OR 0.55 (0.31 to 0.98)
Arnaud et al 20158Meta-analysisDirectLDANo LDA treatment10983NANAHR 0.47 (0.22 to 0.83)
Patients with SLE and low-risk aPL profile
Tarr et al 200716Retrospective cohortDirectLDANo LDA treatment52291 (3.4%)2 (6.9%)Intermediate quality
Tektonidou et al 200913Retrospective cohortDirectLDANo LDA treatment875711 (12.6%)18 (31.5%)High quality
TotalDirect139861220RR 0.39 (0.20 to 0.74)
I2=0%
Non-pregnant women with a history of obstetric APS only (no prior thrombotic events), with or without SLE
Arnaud et al 20147Meta-analysisDirectLDANo LDA treatment1111975 (4.5%)31 (15.7%)OR 0.25 (0.10 to 0.62)
Ruffatti et al 200921Retrospective cohortIndirectLDANo LDA treatment1302318 (5.7%)22 (9.5%)Intermediate quality