Harvest for Health, a Randomized Controlled Trial Testing a Home-Based, Vegetable Gardening Intervention Among Older Cancer Survivors Across Alabama: An Analysis of Accrual and Modifications Made in Intervention Delivery and Assessment During COVID-19

Abstract

Background: Accelerated functional decline is a concern among older cancer survivors that threatens independence and quality of life. Pilot studies suggest that vegetable gardening interventions ameliorate functional decline through improved diet and physical activity.

Objective: The aim of this article was to describe the rationale, recruitment challenges, and enrollment for the Harvest for Health randomized controlled trial (RCT), which will test the impact of a home-based, vegetable gardening intervention on vegetable and fruit consumption, physical activity, and physical functioning among older cancer survivors. Modifications made to the intervention and assessments to assure safety and continuity of the RCT throughout the COVID-19 pandemic also are reported.

Design: Harvest for Health is a 2-year, 2-arm, single-blinded, wait-list controlled RCT with cross-over.

Participants/setting: Medicare-eligible survivors of cancers with ≥60% 5-year survival were recruited across Alabama from October 1, 2016 to February 8, 2021.

Intervention: Participants were randomly assigned to a wait-list control or a 1-year home-based gardening intervention and individually mentored by extension-certified master gardeners to cultivate spring, summer, and fall vegetable gardens.

Main outcome measures: Although the RCT's primary end point was a composite measure of vegetable and fruit consumption, physical activity, and physical functioning, this article focuses on recruitment and modifications made to the intervention and assessments during COVID-19.

Statistical analyses performed: χ² and t tests (α < .05) were used to compare enrolled vs unenrolled populations.

Results: Older cancer survivors (n = 9,708) were contacted via mail and telephone; 1,460 indicated interest (15% response rate), 473 were screened eligible and consented, and 381 completed baseline assessments and were randomized. Enrollees did not differ from nonrespondents/refusals by race and ethnicity, or rural-urban status, but comprised significantly higher numbers of comparatively younger survivors, those who were female, and survivors of breast cancer (P < .001). Although COVID-19 delayed trial completion, protocol modifications overcame this barrier and study completion is anticipated by June 2022.

Conclusions: This RCT will provide evidence on the effects of a mentored vegetable gardening program among older cancer survivors. If efficacious, Harvest for Health represents a novel, multifaceted approach to improve lifestyle behaviors and health outcomes among cancer survivors-one with capacity for sustainability and widespread dissemination.

Trial registration: ClinicalTrials.gov NCT02985411.

Keywords: Cancer; Diet; Older adults; Physical activity; Physical function; Survivorship.

Figure 1.

Study flow diagram of the Harvest for Health randomized controlled trial that tests the impact of a vegetable gardening intervention on vegetable & fruit consumption, physical activity, and physical functioning among older cancer survivors residing in Alabama.

Figure 2.

Logic model of Harvest for Health illustrating the potential mediators of the gardening intervention and their potential influence on study outcomes (primary outcomes are featured in italicized font).

Figure 3.

Participants of the Harvest for Health randomized controlled trial received one raised bed kit (4’×8’×10.5”) or four grow box kits (24.5”×20.5”) depending upon preferences and residential accommodations.