RESULTS
Eighty COS development studies were identified (table S1). Of these, all were registered with COMET and 43 (54%) had parallel registrations with CROWN (figure 1). Two further systematic reviews were registered with CROWN only.
Forty-three (54%) of the registrations represented areas of pregnancy and childbirth, 15 (19%) benign gynaecology and subfertility, 11 (14%) newborn and neonatal health, and 11 (14%) oncology.
Since the previous systematic review(11), 17 protocols, 19 systematic reviews and 16 COS had been published. Of seven previously identified protocols, four had published a COS development study.(17-20) Overall publications had increased in all areas of women’s, newborn and neonatal health (figure 2).