The NCBI Bioproject identifier was listed incorrectly and has been updated correctly to PRJNA530252.
]]>In the interests of transparency, we, the authors, bring attention to two data issues in the results due to coding error. The interpretation of the results of this paper have not changed. We report the omission of 805 children from the cohort of 85 906 children (<1%) where 26 children had died and 779 children had moved out of Wales between the ages of 6–15 years. The death or move from Wales occurred after the outcome of interest: Key Stage 1 (KS1) at age 6–7 years. Of those children omitted who died, low numbers were classified with persistent moderate asthma or wheeze and none were classified with persistent severe asthma or wheeze. We have rerun the analyses and find only up to...]]>