The Delta Garden Study: A Quasi-Experimental, Cross-Sectional, Nested, Pair-Matched Design with Zero-Inflated Endpoints

• Activity Number: 271
• Type: Contributed
• Date/Time: Monday, August 10, 2015 : 3:05 PM to 3:50 PM
• Sponsor: Biometrics Section
• Author(s): Page Moore* and Amy Schrader and Judith L. Weber
• Companies: University of Arkansas for Medical Sciences and University of Arkansas for Medical Sciences and University of Arkansas for Medical Sciences
• Keywords: nested ; zero-inflated ; school garden ; pair-matched

Abstract

The Delta Garden Study is a science-based school garden intervention designed to increase fruit and vegetable (FV) intakes and minutes of moderate to vigorous physical activity (PA), as well as to improve academic achievement and reduce social risk behaviors, in middle school students in Arkansas. The study used a quasi-experimental, cross-sectional, nested, pair-matched design utilizing 6 intervention (school garden) schools and 6 control (no school garden) schools, including over 2,000 6th, 7th and 8th grade students nested within 4-6 science teachers per school. Observed as continuous outcomes, the two primary endpoints were zero-inflated and were collected across multiple time-points. We present the design and analysis of this quasi-experimental, cross-sectional, nested, pair-matched design and the handling of longitudinally collected zero-inflated outcomes.