Discussion

Main findings

This comprehensive systematic review goes someway to update the previous work of Duffy et al.,6 which included three completed core outcome sets relevant to maternal health. Our multi-faceted search strategy identified 32 unique citations relating to 26 core outcome sets: 17 maternal and 9 neonatal COS. Almost half the COS included in the current review had not been included in previous reviews (n = 12) indicating significant progress in COS development. Recently developed COS-STAD criteria were applied to evaluate each COS against minimum standards.8 No COS met all the minimum standards. While scope was well addressed in all COS, patient participation in both stakeholder group and initial outcome generation are areas in need of greater attention. Our findings further indicated greater attention is needed to improve the methods used and reporting of the consensus process. Our findings indicate that standards of COS development have improved from 2018 onwards compared to those prior to 2018 (median standards 6.5 vs 10) likely reflecting the use of COMET guidelines,7 COS-STAD minimum standards,8 and COS-STAR reporting guidelines.18
It is important to acknowledge our findings relate to two distinct groups of COS: those specifically designed as core outcome sets and those that determined outcomes in studies with wider study aims. It is also important to acknowledge that almost half of the included COS pre-date recent methodological guidance.