“…Studies were classed as high risk when follow-up commenced following outpatient chemotherapy ( n = 9), surgery ( n = 8), inpatient hospitalisation (not specifically for surgery, n = 2), or a receipt of a mixture of treatment types ( n = 7), or because either all or the majority of patients had advanced or metastatic cancer at baseline ( n = 5). Prophylaxis was administered to either some (>20%) or all of the participants in 11 studies; with this intervention taking the form of either anticoagulant prophylaxis (with or without mechanical methods) [23],[31],[47],[53],[55],[58],[59], mechanical prophylaxis only [25],[27], aspirin [42], or unspecified prophylaxis [28]. In a further six studies it was stated explicitly that no patients [20],[26],[37],[38],[43],[44] were receiving anticoagulant prophylaxis, and in two further studies [29],[66] there was a small number (<5%) receiving warfarin or heparin.…”