Using ICD-10 diagnostic codes to identify ‘missing’ paediatric patients during nationwide COVID-19 lockdown in Oxfordshire, UK

The study aims to identify ‘missing’ diagnoses amongst paediatric admissions during the UK’s first national lockdown, compared with the previous 5 years. A retrospective observational cohort study of all children (0–15 years) attending for urgent care across Oxfordshire, during the first UK lockdown in 2020, compared to matched dates in 2015–2019, across two paediatric hospitals providing secondary care, including one with tertiary services. Our outcome measures were changes in numbers of patients attending and inpatient diagnoses (using ICD-10 classification) during the first 2020 lockdown, compared with the previous 5 years, were used. We found that total Emergency Department (ED) attendances (n = 4030) and hospital admissions (n = 1416) during the first UK lockdown were reduced by 56.8% and 59.4%, respectively, compared to 2015–2019 (5-year means n = 7446.8 and n = 2491.6, respectively). Proportions of patients admitted from ED and length of stay were similar across 2015–2020. ICD-10 diagnoses in lockdown of 2020 (n = 2843) versus matched 2015–2019 dates (n = 19,946) demonstrated significantly greater neoplasm diagnoses (p = 0.0123). Of diagnoses ‘missing’ in lockdown, 80% were categorised as infectious diseases or their sequelae and 20% were non-specific pains/aches/malaise and accidental injury/poisonings. Conclusions: Pandemic public health measures significantly altered paediatric presentations. Oxfordshire hospitals had a 58% reduction in ED attendances/inpatient admissions, with ‘missing’ diagnoses predominantly infection-related illnesses. These are likely driven by a combination of the following: (1) public health infection control measures successfully reducing disease transmission, (2) parents/carers keeping mild/self-limiting disease at home, and (3) pandemic-related healthcare anxieties. Prospective studies are needed to ensure referral pathways identify vulnerable children, those with social concerns, and avoid delayed presentation. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00431-021-04123-x.