ObjectiveTo describe strategies used to maximise follow-up after a neonatal randomised trial, how these differed for families of different ethnicity, socioeconomic status and urban versus rural residence and investigate relationships between the difficulty of follow-up and rate of neurosensory impairment.MethodhPOD was a multicentre randomised trial assessing oral dextrose gel prophylaxis for neonatal hypoglycaemia. Follow-up at 2 years was conducted from 2017 to 2021. We analysed all recorded contacts between the research team and participants’ families. Neurosensory impairment was defined as blindness, deafness, cerebral palsy, developmental delay or executive function impairment.ResultsOf 1321 eligible participants, 1197 were assessed (91%) and 236/1194 (19.8%) had neurosensory impairment. Participants received a median of five contacts from the research team (range 1–23). Those from more deprived areas and specific ethnicities received more contacts, particularly home tracking visits and home assessments. Impairment was more common among participants receiving more contacts (relative risk 1.81, 95% CI 1.34 to 2.44 for ≥7 contacts vs <7 contacts), and among those assessed after the intended age (76/318, 23.9% if >25 months vs 160/876, 18.3% if ≤25 months).ConclusionsVaried contact strategies and long timeframes are required to achieve a high follow-up rate. Without these, the sociodemographics of children assessed would not have been representative of the entire cohort, and the rate of neurosensory impairment would have been underestimated. To maximise follow-up after randomised trials, substantial effort and resources are needed to ensure that data are useful for clinical decision-making.