No, the Birthplace study did not show that homebirth is more cost effective

The British press is filled today with the latest installment of findings from the Birthplace Study, Cost effectiveness of alternative planned places of birth in woman at low risk of complications: evidence from the Birthplace in England national prospective cohort study published in today’s edition of the British Medical Journal. Although reporters are faithfully trumpeting the press release claims, the real findings are far more nuanced and far less definitive.

To understand why the Birthplace study does not and could not show that homebirth is more cost effective, it is helpful to look at the more detailed version of the findings available here. But first, we need to understand what “cost effectiveness” actually means.

Obviously any time you provide less care or lower quality care, the cost is going to be reduced. Therefore, homebirth is always going to cost less. The real issue is whether outcomes cost less, more or the same when you provide less care. But the study only looked at short term costs, and as the authors acknowledged, it is long term costs that are potentially enormous.

… With regards to the baby, a change from planned place of birth in an OU [obstetric unit] to a non-OU setting will generate lower costs, but this is accompanied by uncertainty surrounding effects on adverse perinatal outcomes…

That’s because:

The limited time horizon of the study meant that the follow up of outcomes for both mother and the baby did not extend beyond the time period of labour care, or higher level postnatal or neonatal care when this was received. Serious adverse outcomes can result in associated life-long health and societal costs, as shown by the size of damages paid in obstetric litigation cases, which represent a substantial cost to the NHS. Less serious, but more frequent, morbidities associated with labour and birth and its management affect women and babies. Follow up over weeks or longer to monitor recovery, or a future assessment of the outcomes for mothers and babies at a later date, would shed more light on long term cost- effectiveness.

In other words, the study CAN’T tell us about cost effectiveness since it does not take into account the largest costs, the costs of caring for a child injured during birth and the massive costs associated with legal settlements for babies who were injured or died.

There is an additional reason why the Birthplace study cannot tell us if homebirth is cost effective. The study population does not reflect the real world population of women who choose homebirth.

As I wrote back in December:

… The list of study exclusion criteria was far more restrictive than the actual exclusion criteria for homebirth in the UK. Therefore, a substantial proportion of the women who actually had a homebirth were excluded from the study even before it began. Of the 18,269 low risk women planning homebirth at the start of the study, 1346 (7.4%) were excluded from the study despite the fact that they went on to have a homebirth under the auspices of the National Health Service.

The bottom line is that the Birthplace study does NOT, indeed cannot, show that homebirth is more cost effective. All it shows it that among women who meet eligibilty criteria far more strict than the actual criteria for homebirth in the UK, homebirth is cost effective in the short term. Of course, the short term is irrelevant since it is in the long term that the true costs are incurred.

It is my impression that the authors of the Birthplace study really, really, really want to put the stamp of approval on a goverment policy to support homebirth that was approved before adequate safety data were available. In terms of cost effectiveness, however, the results are so restricted as to be virtually meaningless.