A randomized trial of a brief intervention to increase fruit and vegetable intake: a replication study among callers to the CIS.

Abstract

Results are reported from a large randomized trial designed to increase fruit and vegetable consumption among callers to the National Cancer Institute's Cancer Information Service (CIS) (n = 1,717). CIS callers assigned to the intervention group (n = 861) received a brief proactive educational intervention over the telephone at the end of usual service, with two follow-up mailouts. Key educational messages and print material derived from the NCI 5 A Day for Better Health program were provided to intervention participants. Participants were interviewed by telephone at 4 weeks (n = 1,307), 4 months (n = 1,180), and 12 months for follow-up (n = 1,016). Results obtained from a single-item measure of fruit and vegetable consumption indicate a significant intervention effect of 0.88 servings per day at 4 weeks follow-up (P < 0.001), 0.63 servings per day at 4 months follow-up (P < 0.001), and 0.43 servings per day at 12 months follow-up (P < 0.001). Using a 7-item food frequency measure, an intervention effect of 0.63 servings per day was obtained at 4 weeks follow-up (P < 0.001), compared with 0.39 servings per day at 4 months follow-up (P = 0.002) and 0.44 servings per day at 12 months follow-up (P = 0.002). A 24-h recall assessment included in the 4-month interviews also yielded a significant intervention effect of 0.67 servings per day (P = 0.015). The vast majority of callers (90%) endorsed the strategy of providing 5 A Day information proactively within the CIS. This brief educational intervention was associated with higher levels of self-reported fruit and vegetable intake at both short- and long-term follow-up. Additional research is recommended to test this or a similar intervention in diverse populations.