Table 2

Impact of mode of delivery definition on resulting maternity statistics: three case studies
Definition rule Numerator Denominator # Trusts Rate (%)
Emergency caesarean section rate
1 89,572 624,199 151 14.35
2 75,370 550,763 140 13.68
3 70,298 525,192 140 13.39
4 81,964 573,497 140 14.29
5 82,701 578,223 140 14.30
Third and fourth degree perineal tear rate amongst instrumental deliveries
1 5,049 76,161 144 6.63
2 4,260 64,661 136 6.59
3 3,965 60,281 135 6.58
4 4,640 70,268 133 6.60
5 4,686 71,205 133 5.58
Elective caesarean section rate for breech presentation
1 11,852 23,640 147 50.14
2 10,066 21,691 139 46.41
3 9,378 17,834 138 52.58
4 10,919 21,776 136 50.14
5 10,928 21,851 136 50.01

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

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