O38 Identifying outcomes for vasa praevia that are important for women: a qualitative study to inform a Core Outcome Set

Background Many studies have demonstrated the key role of ultrasound for the antenatal diagnosis of vasa praevia to prevent perinatal death or severe perinatal morbidity via planned Caesarean birth. However, little is known currently about which outcomes really matter to women. A Core Outcome Set (COS) is the minimum group of outcomes that should be reported in studies on a specific topic so that the results can be compared and combined. Qualitative studies can identify more outcomes within this category, to generate a long list of outcomes to be administered and scored in the Delphi survey, and consensus phase of COS development. Aim To explore the outcomes that are important for women with lived experiences of vasa praevia, to inform the development of a core outcome set, and gain a deeper understanding of why certain outcomes are more important than others in vasa praevia care. Methods An international qualitative study was conducted with women using purposive sampling. Recruitment was facilitated by the International Vasa Previa Foundation. Semi-structured interviews were conducted over the phone, audio-recorded and transcribed verbatim. A descriptive interpretive data analysis was conducted taking inductive and deductive approaches. Results During August to December 2019, 18 women from USA, UK, Canada and Australia who received an antenatal (n=9) or postnatal (n=9) diagnosis of vasa previa were interviewed. Fifty-three outcomes were identified and described under five categories: baby’s survival and health (16 outcomes), mother’s physical health (12 outcomes), mother’s mental and emotional health (9 outcomes), delivery of care (9 outcomes), and resource use and cost (7 outcomes). Conclusion This study identified a list of woman-centred outcomes, some of which are rarely measured in vasa praevia care. The findings from this study will inform the development of an optimal core outcome set for vasa praevia.