Aims There is a move to a seven-day NHS. It is not known whether outcomes differ by day of week for paediatric admissions. Our hypothesis was that the outcomes in and diagnoses of children admitted to hospital will differ by the day of the week.

Methods Details of every acute medical admission to paediatric units in Scotland 2000 to 2013 were obtained. Outcomes were odds for death, admission to intensive care or high dependency unit (ICU/HDU), zero day admission, length of stay and readmission within the same month. The odds for being admitted with one of the five most common conditions and five conditions we felt were commonly admitted to HDU/ICU were calculated for each day with reference to Monday.

Results There were 570,403 admissions, most (16%) presented on Mondays and least (12%) on Saturdays. The odds of death were not related to the day of admission. The odds for ICU/HDU admission were only increased on Saturdays (1.18 [1.05, 1.31]) and Sundays (1.27 [1.14, 1.41]). The odds for zero day admission rose progressively from Monday to Friday (Friday OR 1.09 [1.07, 1.11]) but were reduced on Sundays (OR 0.94 [0.92, 0.96]). The odds for readmission were highest after initial presentation on a Monday and fell progressively to 0.86 [0.82, 0.91] for Sunday admissions. The mean length of stay was similar for all days. Presentations with URTI, vomiting and diarrhoea, “viral infection” and bronchiolitis had a mostly even distribution across the week. The odds for admissions with febrile convulsions, croup and meningococcal diseases were only increased on Saturdays and Sundays (by 25–30%). The odds for admission with asthma and diabetic ketoacidosis (DKA) were remarkable for falling by 25–30% between Monday and Friday but then being highest after Sunday admission (OR for asthma 1.08 [1.02, 1.14] and for DKA 1.18 [1.02, 1.37]).

Conclusion Although proportionately more very sick children present at weekends, there is no increase in mortality and indices of quality of care are no worse on weekends compared to weekdays. As the traditional working week progresses, there are divergent trends in the proportions with zero day admissions and readmissions, and notable differences in presentations with non-communicable diseases which require further evaluation.