|Impact of mode of delivery definition on resulting maternity statistics: three case studies|
|Definition rule||Numerator||Denominator||# Trusts||Rate (%)|
|Emergency caesarean section rate|
|Third and fourth degree perineal tear rate amongst instrumental deliveries|
|Elective caesarean section rate for breech presentation|
Key to definition rules.
1 = Use all episodes with an OPCS method of delivery code & base method of delivery definitions on OPCS codes alone.
2 = Use all episodes with a delmeth code & base method of delivery definitions on delmeth codes alone.
3 = Use only episodes in which both OPCS and delmeth codes are present and in agreement; base method of delivery definitions on agreed method of delivery code.
4 = Use all episodes with an OPCS method of delivery code excluding those from trusts with a poor agreement rate; base method of delivery definitions on OPCS codes alone.
5 = Use all episodes excluding those from trusts with a poor agreement rate; base method of delivery definitions on OPCS codes, or delmeth codes if OPCS codes are missing.
Knight et al.
Knight et al. BMC Health Services Research 2013 13:200 doi:10.1186/1472-6963-13-200