​Summary: The California Health Interview Survey (CHIS) has consistently strived to provide accurate health and health care information about children aged 0-11 in California. However, the growing difficulties with survey data collection have prompted CHIS to consider a methodological redesign for child data collection. In 2019, CHIS replaced its historic telephone mode with a mixed-mode web and telephone design using address-based sampling. In conjunction with the general sampling and data collection redesign, CHIS implemented two new methods to specifically increase the number of child survey completes in 2019: 1) placing the child survey questions before the adult survey and 2) oversampling households with children through predictive modeling.

Findings: These changes helped CHIS achieve over 3,000 child completes in 2019 — the highest number of child completes since CHIS 2012. The innovative methods used here have promise for many other surveys looking to add or improve child survey data collection.