Monthly food baskets were provided to the nutrition only group. Food baskets included basic foods to sustain a family of three over one month's time, such as rice and evaporated milk. Food baskets were valued at approximately $28 US Dollars per basket.

The CASITA intervention was given by a community health worker (CHW) and involves individual and group modalities. HOME-CASITA took place at the dyad's place of residence, and the GROUP-CASITA at a local community center. All CASITA participants received 12 weekly sessions over 3 months. Interventions retain core elements of the SPARK approach: coaching parents on child development stimulation and providing social support and encouragement. Each session is as follows: 1) Child observation & knowledge sharing about child development; 2) Practice of reciprocal attention focusing and social interaction activities; 3) Parent encouragement on behavior and developmental interactions; and 4) Parent social support through referral assistance, reassurance, and validation of parent's concerns.

The Ages and Stages Questionnaire (ASQ) is an internationally-validated instrument that can be used to assess change in developmental risk over time. Fernald et al incorporated additional observation-based assessments and the following modifications: 1) addition of child observation exercises to allow for validity check of parent responses (original ASQ questions), and 2) the incorporation of ASQ questions from the next highest age range. The Extended Ages and Stages Questionnaire (EASQ) was utilized as an assessment tool to allow us to better quantify degree of risk at baseline (based on quintiles of scores). By incorporating ASQ questions from the next two highest age ranges, scores will be continuous across the study period of three. The EASQ has been applied to children in four countries, including 2,845 children in Peru.

The Infant Toddler Home Observation Measurement of the Environment (HOME) evaluates parenting and home influences on child development.