1 Department of Family Medicine, Queen's University, Kingston, Ontario, Canada bayoumi@queensu.ca.
2 Centre for Studies in Primary Care, Queen's University, Kingston, Ontario, Canada.
3 Department of Family Medicine, Queen's University, Kingston, Ontario, Canada.
4 Concordia University, Montreal, Quebec, Canada.
5 University of Toronto Temerty Faculty of Medicine, Toronto, Ontario, Canada.
6 Department of Statistics, University of Manitoba, Winnipeg, Manitoba, Canada.
7 Department of Family and Community Medicine, University of Toronto, Toronto, Ontario, Canada.
8 Canadian Institute for Health and Information, Ottawa, Ontario, Canada.
9 Memorial University, St. John's, Newfoundland and Labrador, Canada.
10 University of Toronto, Toronto, Ontario, Canada.
11 Department of Pediatrics, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.
12 McGill University, Montreal, Quebec, Canada.

Background: Well child visits (WCV) are fundamental to preventive primary care. We examined trends in WCV attendance during the COVID-19 pandemic and characterised variation by patient and provider characteristics.

Methods: Deidentified electronic medical records from two academic practice-based research networks in Ontario were used to create age-specific cohorts of children under age six attending WCVs from 2015 to 2022. Patients' residential postal codes were linked to neighbourhood-level measures to estimate socioeconomic status. Monthly visit rates were modelled using segmented linear regression with autoregressive residuals. Changes associated with COVID-19 were assessed using level change and trend change of monthly visit rates.

Findings: For the 53 256 included children, WCV attendance increased from 2015 to 2020 for cohorts aged 15 months and younger and was stable for 18-month, 2-3-year and 4-6-year visits. The COVID-19 pandemic was associated with decreased WCV attendance in all ages except ages 1-2 weeks, 1 month, 12 months, 15 months and 18 months, in whom attendance was unchanged. The rate of change in WCV attendance rates pre-COVID-19 compared with post-COVID-19 was unchanged, with the exception of increased rate of change for the 1-2 weeks and 2-3 years old cohorts. Lower attendance rates were observed in children residing in neighbourhoods with the highest material deprivation, rural regions and those whose family physicians were men or older than 65 years.

Interpretation: Prepandemic gains in WCV attendance were stable or improved after the initial reductions observed at the pandemic onset, suggesting that WCVs were prioritised by family physicians and families. Targeted strategies are needed to improve WCV attendance for vulnerable groups.