Adverse outcomes of labour in public and private hospitals in Australia
Authors: Nick Evans, Girvan Malcolm and Adrienne Gordon
Published online: 16 November 2009
To the Editor: Of the many problems with the study by Robson and colleagues,1 the one that concerns us most is the outcome of perinatal death. The headline that this is twice as high in public hospitals has the potential to scare those who have no choice about where they give birth. Both the public and the medical community have a right to expect that this outcome is rigorously and accurately represented. We do not believe this to be the case.
The perinatal death rate is made up of stillbirths and neonatal deaths in the first 28 days of life. Stillbirths will comprise 70% of all perinatal deaths, and more than 90% of stillbirths after 37 weeks’ gestation will occur before the onset of labour.2,3 It cannot be excluded that this relates to model of care but, because less than 10% of these stillbirths will have occurred during delivery, it is most certainly not related to the type of birth hospital or the interventions performed during labour. Most likely, it reflects differences in intrinsic risk that have not been controlled for by Robson et al.1
The neonatal death component of this statistic is probably confounded by ascertainment bias. Most neonatal deaths after 37 weeks’ gestation occur for two reasons: intrapartum hypoxia–ischaemia and severe congenital abnormalities. When the latter are diagnosed antenatally, the mothers will often be transferred to tertiary public hospitals for a second opinion and further management. Babies with undiagnosed lethal abnormalities or severe intrapartum hypoxia will invariably be transferred postnatally to a tertiary public hospital neonatal intensive care unit, where death often occurs after withdrawal of intensive care. The midwives data collection form is filled in at the birth hospital, and the baby is categorised as “discharged”, “transferred” or “died”. The 2006 national perinatal data collection report specifically cautions:
Ascertainment of neonatal deaths within 28 days of birth is likely to be incomplete. In particular, deaths occurring among babies transferred to another hospital, readmitted to hospital or dying at home may not be known to midwives who collect these data or staff who compile state and territory data.2
Thus, it is unlikely that the difference in perinatal mortality described by Robson et al1 has anything to do with the birth hospital. To represent it as such in the public arena is irresponsible. Further, for the MJA to misrepresent “perinatal mortality” as “neonatal mortality” in the media release about this article defies belief.
References
- Robson SJ, Laws P, Sullivan EA. Adverse outcomes of labour in public and private hospitals in Australia: a population-based descriptive study. Med J Aust 2009; 190: 474-477. 0_CHDBHJAI
- Laws P, Hilder L. Australia’s mothers and babies 2006. Canberra: Australian Institute of Health and Welfare, 2008: 67-73. (AIHW Cat. No. PER 46.) 0_i1091856
- Getahun D, Ananth CV, Kinzler WL. Risk factors for antepartum and intrapartum stillbirth: a population-based study. Am J Obstet Gynecol 2007; 196: 499-507. 0_CHDGDFCF