Oral anticoagulation is preferable to injected, but only if it is safe and effective: An interview study of patient and carer experience of oral and injected anticoagulant therapy for cancer-associated thrombosis in the select-d trial

Background: Cancer patients have a four- to fivefold greater risk of thrombosis than the general population. Recommended treatment for cancer-associated thrombosis is 3-6 months of low-molecular-weight heparin. The 'select-d' trial is an open-label, randomised, multi-centre pilot trial in patients with cancer-associated thrombosis, utilising dalteparin (low-molecular-weight heparin) versus rivaroxaban (a direct oral anticoagulant), to assess effectiveness and safety. Aim: To explore patient and informal carers' experiences of cancer-associated thrombosis and their experience and understanding of the risk-benefit of thrombosis treatment. Design: Qualitative substudy of the select-d trial, using semi-structured interviews. Interviews were audio-recorded and transcribed. Data were analysed using Framework Analysis. Participants: Participants were purposively sampled (n = 37 patients; 46% male; age 40-89; 9 with carer present). Results: Three themes were found: experience of cancer-associated thrombosis, experience of anticoagulation and risk-benefit balance of the two modes of administration. Some were shocked by their thrombosis diagnosis (most were unaware of their risk), but others found it insignificant compared with cancer. Most patients found tablets more convenient, but injections were acceptable in the context of having cancer. While most were happy to follow medical advice, others weighed preference on the basis of effectiveness. Conclusion: Lack of awareness of thrombosis risk is concerning; cancer patients must be informed to enable prompt help-seeking. Tablets could provide a welcome choice for patients if there is equivalent risk-benefit to injected anticoagulants. Patients trust their clinicians to tailor their treatment. Future research could explore the effect of routine information giving about the risk of thrombosis.