Maternity units in England operate at 100% capacity much of the time. When capacity is breached, units may occasionally have to close temporarily to new admissions, causing stress to women in labour and undermining their choice over where to have their babies.
New work by IFS unpicks some of the causes of closures. We use new data on closures of UK maternity units between 2011 and 2015 obtained through Freedom of Information requests, linked to data from maternity admission records.
The relationship between closure and the number of "spontaneous" admissions - those where women have gone into labour naturally, rather than through a planned induction or c-section - are unsurprising. More admissions means more chance that a maternity unit has to close, both on the day of closure and the day before. Closures are two and a half times more likely on the sixty busiest days of the year than on the least busy sixty.
While the relationship between closures and admissions was predictable, the patterns by day of the week are much harder to explain. The number of closures was 30% greater between Thursday and Saturday than between Monday and Wednesday. Although a weekend effect might be expected, it is unclear why closures are far more likely on a Thursday than a Tuesday. One explanation is that it is harder to fill rosters towards the end of the week. Alternatively women whose labour is induced on Monday or Tuesday may remain in hospital, which becomes progressively more crowded as the week goes on. Further research is needed to identify the cause, but in either case, the pattern by day of the week suggest that some closures could be predicted and prevented by improving staff availability or the scheduling of planned admissions.
Rates of closures also vary by month of year and point to constraints on capacity and the difficulty with rostering staff. Closures are highest in September. This coincides with a baby boom that occurs nine months after the Christmas and New Year period. Closures during this period are perhaps inevitable, unless the NHS is prepared to fund excess capacity for much of the year. However, we also find higher rates of closure over the summer months and in December, when people in England tend to take holidays. There are 50% more closures in June than January, even though the number of births in the two months is approximately the same. Some of the higher numbers of closures in the summer months could be attributable to an increased number of premature babies in the run up to the September baby booms. However, this does not explain higher rates of closure in December.
Hospitals where maternity units close more frequently are also more likely to miss the target of treating 95% of A&E patients within 4 hours. Specifically, we find that for hospitals that close maternity units between zero and two times a year, around 8.5% of A&E patients have to wait more than four hours for treatment in A&E, rising to 11% when units close more than ten times per year.
Since there is very little overlap between maternity and A&E patients, this result suggests that missing targets and closing maternity units is the result of common pressures, rather than spillovers across departments. Units that close the most tend to serve larger local populations, suggesting that population pressure are one possible cause. Reassuringly, however, there is no evidence that overall death rates, as measured across all departments in the hospital, are higher when the number of closures is high.
In summary, patterns of closure by day of the week and season suggest that some closures are preventable, through improving staff availability or the scheduling of planned admissions.
However, these actions would be costly. For instance, many doctors and midwives have their own care commitments that mean they need to work flexibly, and making staff take leave in November or February is not attractive or realistic. More work is needed on what actions would be required to prevent closure, how much those actions would cost, and, most importantly, how those costs are weighted against the benefits to women of avoiding closure and the needs of competing services within the NHS.
Elaine Kelly is a senior research economist at the Institute for Fiscal Studies