Outcome Reporting in Studies on Perinatal Venous Thromboembolism: A Systematic Review [28O]

INTRODUCTION: The perinatal period places women at risk of developing venous thromboembolism (VTE). This systematic review aims to identify variation in outcome reporting in studies on the prevention and management of VTE in pregnant women, as a preliminary step towards developing a core outcome set to standardize outcome reporting in studies on perinatal VTE. METHODS: MEDLINE, EMBASE and www.clinicaltrials.gov were searched for clinical trials, registrations and observational studies with over 10 participants published between 1998 and 2018. Titles and full texts were screened in duplicate. Studies were classified as those focusing on VTE prevention vs. management. Reported outcomes were categorized under mortality, clinical, functional, resource use and adverse events based on a taxonomy of outcomes for medical research. Proportions of studies reporting each outcome were determined. Definitions and measurement tools were noted for each outcome. RESULTS: Of 7541 results screened, 69 studies (36 prevention+33 management) were included. Of the 165 outcomes, 25 were related to the fetus. Maternal outcomes mostly represented the clinical domain (96/152), with fewer adverse events (31), resource use (7), mortality (3) and functioning (3). There was very little consistency in how outcomes were defined or measured. CONCLUSION: Variation in outcome reporting and measurement in studies on perinatal VTE presents challenges for study comparison and meta-analysis. Outcomes related to fetal wellbeing, adverse events, resource use and functioning are inadequately represented. Qualitative interviews with patients and care providers to determine their perception on these outcomes is an important step in developing this core outcome set.