Evaluating Care Integration Between Pediatric Primary Care Providers and WIC Nutritionists

Infant Weight Gain

Change in weight-for-age z-score (WAZ) from birth to 6 months, with positive conditional weight gain scores indicating rapid or faster than average infant weight gain and negative scores indicating slower than average infant weight gain.

Child Body Mass Index

Body mass index z-scores at child age 24 months, calculated using WHO Child Growth Standards.

Parent Feeding Practices

Differences in parent feeding practice scores between intervention and control conditions will be measured using the 12-item Baby's Basic Needs Questionnaire, which assesses context-based (e.g., before bed) and emotion-based (e.g., food to soothe) feeding during infancy. Items are scored on a 5-point scale with responses from Never (1) to Always (5). Items are averaged to create a score for each subscale, and all items are averaged to create a total score, with higher scores indicating greater use of context-based, emotion-based, and total food to soothe.

Parent Feeding Practices

Differences in parent feeding practice scores between intervention and control conditions will be measured using the Structure and Control in Parent Feeding questionnaire, which assesses responsive, structure-based feeding practices (i.e., limit-setting, consistent routines) and non-responsive, control-based feeding practices (i.e., restriction, pressure to eat) during toddlerhood. Items are scored on a 5-point Likert scale (0 = never to 4 = always), with higher scores indicating higher frequency of engagement in a specific feeding behavior.

Parent Feeding Practices

Differences in parent feeding practice scores between intervention and control conditions will be assessed using the Feeding to Manage Child Behavior questionnaire, a 9-item measure that assesses parents' use of food to soothe and food as reward. Items are scored on a 5-point Likert scale (0 = never- 4 = always), with higher scores indicating higher frequency of engagement in food to soothe or as a reward.

Child Diet Quality

Differences in child diet quality scores between the intervention and control conditions will be measured using the Mediterranean Eating Pattern for Americans-Child version. This is a 6-item parent-report measure of a child's diet quality, tailored to the child's developmental age, that captures recommended foods (e.g., fruits, vegetables, human milk) and non-recommended foods (e.g., sweets, SSBs, fast foods). The total score could range from 0 to 6. Scores will be converted to points on a 100-point scale using the 6-item measure's quantiles. For example, scores of 0 (0 points), 3 (55 points), and 6 (100 points), with higher scores meaning better diet quality.

Moderators of Intervention Effectiveness on Child BMI Z-scores

Moderators of intervention effectiveness on child BMI z-scores will include child characteristics (e.g., sex, temperament, appetitive traits), maternal psychosocial factors (e.g., perceived stress, social support), and social determinants of health (e.g., income, food and nutrition security, access to reliable transportation).