Objective:
To explore the impact of the measures taken to combat COVID-19 on the patterns of acute illness in children presenting to primary and secondary care for North-West London.

Design / Setting / Participants:
Retrospective analysis of 8,309,358 primary and secondary healthcare episodes of children <16 years registered with a North-West London primary care practice between 2015 and 2021.

Main outcome measures:
Numbers of primary care consultations, emergency department attendances (ED) and emergency admissions during the pandemic were compared with those in the preceding five years. Trends were examined by age and for ICD10-coded diagnoses of: infectious diseases, and injuries and poisonings for admitted children.

Results:
Comparing 2020 to the 2015-19 mean, primary care consultations were 22% lower, ED attendances were 38% lower and admissions 35% lower. Following the first national lockdown in April 2020, primary care consultations were 39% lower compared to the April 2015-19 mean, ED attendances were 72% lower, and unscheduled hospital admissions were 63% lower. Admissions >48 hours were on average 13% lower overall during 2020, and 36% lower during April 2020. The reduction in admissions for infections (61% lower than 2015-19 mean) between April-August 2020 was greater than for injuries (31% lower).

Conclusion:
The COVID-19 pandemic was associated with an overall reduction in childhood illness presentations to health services in North-West London, most prominent during periods of national lockdown, and with a greater impact on infections than injuries. These reductions demonstrate the impact on children of measures taken to combat COVID-19 across the health system.