Association between day of delivery and obstetric outcomes: observational study

Abstract

Study queStionWhat is the association between day of delivery and measures of quality and safety of maternity services, particularly comparing weekend with weekday performance? MethodSThis observational study examined outcomes for maternal and neonatal records (1 332 835 deliveries and 1 349 599 births between 1 April 2010 and 31 March 2012) within the nationwide administrative dataset for English National Health Service hospitals by day of the week. Groups were defined by day of admission (for maternal indicators) or delivery (for neonatal indicators) rather than by day of complication. Logistic regression was used to adjust for case mix factors including gestational age, birth weight, and maternal age. Staffing factors were also investigated using multilevel models to evaluate the association between outcomes and level of consultant presence. The primary outcomes were perinatal mortality and-for both neonate and mother-infections, emergency readmissions, and injuries. Study anSwer and liMitationSPerformance across four of the seven measures was significantly worse for women admitted, and babies born, at weekends. In particular, the perinatal mortality rate was 7.3 per 1000 babies delivered at weekends, 0.9 per 1000 higher than for weekdays (adjusted odds ratio 1.07, 95% confidence interval 1.02 to 1.13). No consistent association between outcomes and staffing was identified, although trusts that complied with recommended levels of consultant presence had a perineal tear rate of 3.0% compared with 3.3% for non-compliant services (adjusted odds ratio 1.21, 1.00 to 1.45). Limitations of the analysis include the method of categorising performance temporally, which was mitigated by using a midweek reference day (Tuesday). IntroductionPrevious studies, across a range of countries, have identified higher mortality in patients admitted on weekends (compared with weekdays) across a range of medical conditions-a phenomenon termed the "weekend effect." [1][2][3][4][5][6] This calls into question the idea that quality of care is equal irrespective of when someone presents at hospital. However, not all studies have identified an association between poor outcomes and out of hours periods. [7][8][9] MacFarlane published a paper in 1978 that showed a seven day cycle in birth numbers across England (and Wales) and that perinatal mortality was higher among babies born at weekends. 10 Similar studies in the 1970s found similar phenomena in other developed countries. 11 12 The delivery of obstetric care has changed dramatically since that time; however, where the weekend effect has been evaluated, this has predominantly been based on mortality. In setting out key challenges in obstetric care-albeit in a broader, global context-a paper from the World Health Organization highlighted ineffective referral to, and inadequate availability of, 24 hour quality services to emergency obstetric care services. 13 We investigated the association between day of delivery and the quality and safety of care and, in particular, compared...

Weekend working: a retrospective cohort study of maternal and neonatal outcomes in a large NHS delivery unit

“…By contrast, a recent UK study found that there was an increase in perinatal mortality and maternal infection on weekend days (11). This study took the unusual step of comparing weekend days to those deliveries occurring on Tuesdays only, rather than a comparison over all weekdays.…”

Is there a weekend effect in obstetrics?

“…4-7 A study by Palmer and colleagues (doi:10.1136/bmj.h5774) helps to fill this evidence gap, presenting a thoughtful analysis of adverse birth outcomes in a retrospective cohort from the United Kingdom. 8 This study found that some adverse outcomes were slightly but significantly more common among weekend deliveries, most notably perinatal mortality. Although the magnitude was small (an unadjusted absolute increase of 0.9 deaths per 1000 deliveries (0.73% v 0.64%); adjusted odds ratio 1.07, 95% confidence interval 1.02 to 1.13), the gravity of this outcome demands our attention.…”

“…Despite some notable examples of null findings, 4 enough evidence now exists for us to reasonably suspect that out of hours deliveries are at higher risk for adverse outcomes. [6][7][8] The evidence for higher risks among night time deliveries is even stronger. 9-12 However, additional well designed studies are needed to determine whether these findings are robust within and across populations.…”

A 7/7 NHS: what price equity?

“…However, the NHS has produced a slew of policy documents and evidence reviews, and there is some (limited) research on mortality differences between patients admitted at weekends compared with those admitted during the week and currently just one published study of the cost effectiveness of seven day working in secondary care. [2][3][4][5][6][7][8][9][10][11][12] Just as demand and need for hospital services vary by hour of the day (meaning that it would be inefficient to maintain a 24/7 service, with no variation in staffing or services between day and night time), so there is also variation between weekends and week days. There are fewer admissions at weekends than on week days ( fig 1⇓), and the nature of the patients and their illness varies too; non-emergency cases are generally admitted on a week day, for example.…”

“…The statistical and interpretive difficulties of identifying a weekend admission effect is illustrated by Palmer et al's research, which estimated a 7% higher relative risk of a still birth for mothers admitted at weekends compared with those admitted on a Tuesday. 9 This finding was heavily criticised, 10 and indeed, the paper itself noted extensive limitations in its analysis.…”