Procedures
illnesses and simple games, malnutrition
HEARING IMPAIRMENT, RECRUITMENT, BLIND, MALNUTRITION
Caregivers of eligible infants were contacted via phone, and a standard participation invitation script was used to explain the study. Appointments were scheduled at a study facility nearest the family’s home. All consent forms and questionnaires were translated and back translated from English to Kiswahili and Dholuo.Pregnancy, birth and neonatal course data were extracted from the cRCT database and confirmed with the caregiver when possible. Assessors were blind to the child’s birth weight and gestational age, and questions regarding these variables were not asked at the study visit. The sequence of assessments was: (1) caregiver interview for sociodemographic information, medical history including growth, illness and development, and the TQQ; (2) direct neurodevelopmental assessments including the Malawi Developmental Assessment Tool (MDAT) and Hammersmith Infant Neurological Examination (HINE); and (3) physical examination including anthropometric measurements. Details of the anthropometric measurement standardised guidelines and the three neurodevelopmental assessment tools are in 
All assessments were conducted in a conducive environment, when the child was settled and in relatively stable health, and complied with health and safety procedures. The research team consisted of clinical officers and nurses, all trained in study procedures and certified to conduct neurodevelopmental assessments. Two team members were present for each assessment, with one conducting the assessment and one observing and recording findings. A paediatrician trained in all study procedures provided consultation and regular supervision.After assessment, feedback on the child’s neurodevelopment and health was given to the caregiver and their concerns were addressed. Caregivers were also given information on nutrition, danger signs for common childhood illnesses and simple games to play with their child. Children identified with any significant health or developmental concern, such as hearing impairment, acute malnutrition or neurodevelopmental delay, were referred to appropriate follow-up care customised to the identified need (eg, audiology, nutrition support), with costs of up to four care visits covered by the study.Data collection was paper based, with subsequent entry into a Microsoft Access database. Double entry and verification to test for logical sequence, discrepancies and outliers was completed. Data were deidentified and stored on an encrypted server within a locked study facility. Efforts to address potential bias included sequential recruitment toward sample size goal, reporting of differences between consenting individuals and the eligible sample, similar procedures at multiple sites to reduce loss to follow-up risk that might be associated with travel to a central location, and blinding of assessors as to child’s birth weight and gestational age.