Good quality science depends on accurate data and being able to accurately interpret the results of analysis conducted on these data. It is therefore important for studies such as ALSPAC to assess if the way people take part in research has an effect on how researchers should interpret the data.

This study aims to assess the PEARL Consent Campaign - which asked participants to re-enrol into the study upon reaching age 18 and also for consent to link to their routine health and administrative records. We want to understand if the characteristics of participants who responded by returning their consent form, or responded with different consent decisions, differ from other participants - and if these differences may introduce bias into study findings. We will also consider if any lessons can be learnt as to how studies may improve requests for consent in the future. This project will contribute to wellbeing of children by forming part of the documentation used by future researchers to help ensure their findings are accurate.