The proposed list of APOs

At the beginning of the QAMC project, it was proposed that the following 20 adverse pregnancy outcomes should be modelled:

1. Antibiotics started > 24 hours after term vaginal delivery
2. Inborn term infant with seizures before discharge
3. Maternal hospital stay > 5 days (> 7 days if CS)
4. Maternal re-admission within 14 days of discharge
5. Non-standard reason for induction
6. Delivery unattended by any midwife or doctor
7. Primary CS for fetal distress
8. Primary CS for failure to progress
9. Birthweight < 2.5kg or RDS following induction
10. Postpartum return to delivery suite/theatre
11. Excess blood loss (> 450ml): transfusion or Hb drop > 3.5g/dl
12. Non-standard reason for induction followed by CS
13. Unintended injury to a maternal organ
14. Birthweight < 2.5kg or RDS following a planned repeat CS
15. Neonatal mortality up to 28 days of age
16. Fetal death prior to labour
17. Fetal death during labour
18. Eclampsia
19. Maternal cardio-pulmonary arrest
20. Maternal death.

Each of these outcomes is an important measure of the quality of care provided to mothers and babies. But, while it is certainly desirable to reduce the incidence of any of these APOs, it does not necessarily make sense to do this by predicting the risk of a mother or baby experiencing such an outcome. For example, it would be of little use to forecast a high risk of maternal re-admission within 14 days of discharge without identifying the root cause of that outcome. This, and other factors, allowed the list of 20 APOs to be reduced to a smaller number of outcomes that are both meaningful and feasible to predict.

Certain items in this list are rendered infeasible to model accurately by their low incidence ( e.g. , maternal death), their absence in any of the perinatal databases we had access to ( e.g. , unintended injury to a maternal organ) or their inability to be precisely defined in terms of database information that we did have access to ( e.g. , postpartum return to delivery suite/theatre).

Further difficulties were caused by some APOs that actually specified a combination of adverse outcomes. Primary Caesarian section for failure to progress is a clear example of this. It is well known that Caesarian section rates vary significantly between different countries, different hospitals and different obstetricians. Any system that tried to predict risk of Caesarian section would have to model the decision process of different obstetricians - a challenging prospect, to say the least. It was decided that these compound APOs should be broken into their component outcomes.

So, after a careful review, the list of 20 APOs was reduced to 5 APOs that seemed feasible to tackle:

1. Eclampsia/pre-eclampsia condition
2. Failure to progress in labour
3. Fetal distress
4. Low birthweight
5. Respiratory distress syndrome (RDS).

Definition of failure to progress in labour

Put simply, a failure to progress means that the natural course of labour has stalled before delivery, placing the wellbeing of both mother and child at risk. In terms of the SMR2 data, failure to progress was indicated by the presence of any of the following ICD-9 codes in a case record:

• 6622 prolonged second stage;
• 6620 prolonged first stage;
• 6603 persistent occipitoposterior;
• 6621 prolonged labor not otherwise specified;
• 6591 fail induction labor not otherwise specified.