ObjectivesThe aim of this sequential mixed-methods study was to describe and understand how paediatric short stay admission (SSA) rates vary across Health Board regions of Scotland.DesignExploratory sequential mixed-methods study. Routinely acquired data for the annual (per capita) SSA to hospital were compared across the 11 regions. Five diverse regions with different SSA per capita formed cases for qualitative interviews with health professionals and parents to explore how care pathways, service features and geography may influence decisions to admit.SettingScotland.ParticipantsAll children admitted to hospital 2015–2017. Healthcare staff (n=48) and parents (n=15) were interviewed.ResultsOf 171 039 urgent hospital admissions, 92 229 were SSAs, with a fivefold variation between 14 and 69/1000 children/year across regions. SSAs were higher for children in the most deprived compared with the least deprived communities. When expressed as a ratio of highest to lowest SSA/1000 children/year for diagnosed conditions between regions, the ratio was highest (10.1) for upper respiratory tract infection and lowest (2.8) for convulsions. Readmissions varied between 0.80 and 2.52/1000/year, with regions reporting higher SSA rates more likely to report higher readmission rates (r=0.70, p=0.016, n=11). Proximity and ease of access to services, local differences in service structure and configuration, national policy directives and disparities in how an SSA is defined were recognised by interviewees as explaining the observed regional variations in SSAs. Socioeconomic deprivation was seldom spontaneously raised by professionals when reflecting on reasons to refer or admit a child. Instead, greater emphasis was placed on the wider social circumstances and parents’ capacity to cope with and manage their child’s illness at home.ConclusionSSA rates for children vary quantitatively by region, condition and area deprivation and our interviews identify reasons for this. These findings can usefully inform future care pathway interventions.