Telephone-Delivered Dietary Intervention in Patients with Age-Related Macular Degeneration: 3-Months Post-Intervention Findings of a Randomised Controlled Trial

Abstract

Background: There is an evidence-practice gap between the dietary recommendations for age-related macular degeneration (AMD) presented in the literature and those practiced by patients. This study reports on the 3-months post-intervention results of a randomised controlled trial (RCT) evaluating telephone-delivered dietary counselling aiming to improve dietary behaviors among patients with AMD.Methods: 155 AMD patients (57% female, aged 78 ± 8 years; control: 78, intervention: 77), primarily residing in New South Wales, Australia were recruited into the RCT at baseline. Participants completed a baseline questionnaire and short dietary questionnaire for age-related macular degeneration (SDQ-AMD). The intervention included an evidence-based nutrition resource and four monthly calls with a dietitian in addition to usual care; the control arm only received usual care. Immediately post-intervention, participants in the intervention arm were invited to repeat the SDQ-AMD and complete a feedback form. At 3-months post-intervention, all participants were invited to repeat the SDQ-AMD. Statistical analyses included t-tests and McNemar’s test to determine change in dietary intakes and proportion of participants meeting the dietary recommendations, respectively; level of significance for all statistical analyses was p <0.05. Descriptive statistics were used to describe adherence to and acceptability of the intervention.Results: At 3-months post-intervention compared to baseline, there were significant improvements within the intervention arm including increased intakes (mean serves ± SE) of dark green leafy vegetables (0.99 ± 0.17 vs 1.71 ± 0.22; p = 0.003) and legumes (0.69 ± 0.10 vs 1.12 ± 0.16; p = 0.02), and reduced intakes of specified discretionary foods (8.31 ± 0.76 vs 6.54 ± 0.58, p = 0.01). Between study arms, intakes of nuts were significantly higher in the intervention arm (control: 2.71 ± 0.32 vs intervention: 3.96 ± 0.51; p = 0.04) at 3-months post-intervention. Overall feedback about the intervention was positive, with all completers (n = 74) finding the program worthwhile and 98.7% (n = 73) indicating they would recommend it to others. Conclusion: This novel intervention was well-received and significantly improved the dietary intakes of dark green leafy vegetables, legumes and discretionary foods within the intervention arm.Trial registration: Australian New Zealand Clinical Trials Registry; ACTRN12618000527268; registered 10 April 2018.