Table 1.
Details of study data collection instruments
| Variable | Method | Baseline | Monthly | Effectiveness phase (12 months) | Extended implementation (24 months) | Study personnel | Comments |
| Sociodemographic data | Basic health history and demographics survey | X | Study nurse | Online supplemental file 1 | |||
| Development (primary outcome) |
Bayley Scales of Infant Development, Version 340 | X | X | X | Study psychologist or paediatrician | Commercial instrument | |
| Home environment (secondary outcome) |
Home Observation for Measurement of the Environment13 | X | X | X | Study nurse | Commercial instrument | |
| Anthropometrics | Weight (kg), length (cm) | X | X | X | Study nurse | WHO Growth Standards will be used to convert to z-scores41 | |
| Diet quality | Minimum dietary diversity, minimum meal frequency and minimum acceptable diet | X | X | X | Study nurse | WHO Infant and Young Child Feeding indicators42 | |
| Haemoglobin | Hemocue Hb 201+ | X | X | X | Study nurse | Using manufacturer’s protocol | |
| Focus groups/interviews with stakeholders | Focus groups and interview guides to be developed in year 1 of the project | X | X | X | Qualitative research staff | Instruments under development during first 1 year of project | |
| Cost to caregivers/families | Survey | X | Frontline workers | Instruments under development during first 1 year of project | |||
| Cost to frontline workers | Survey | X | Research coordinator | Instruments under development during first 1 year of project | |||
| Costs to health system | Survey | X | Research coordinator | Instruments under development during first 1 year of project |