Mediators and Moderators of the Effectiveness of a Community Health Worker Intervention That Improved Dietary Outcomes in Pregnant Latino Women

Abstract

Background: Pregnancy is an opportune time to initiate diabetes prevention strategies for minority and underserved women, using culturally tailored interventions delivered by community health workers. A community-partnered randomized controlled trial (RCT) with pregnant Latino women resulted in significantly improved vegetable, fiber, added sugar, and total fat consumption compared to a minimal intervention group. However, studying RCT intervention effects alone does not explain the mechanisms by which the intervention was successful or help identify which participants may have benefitted most.

Purpose: To improve the development and targeting of future community health worker interventions for high-risk pregnant women, we examined baseline characteristics (moderators) and potential mechanisms (mediators) associated with these dietary changes.

Method: Secondary analysis of data for 220 Latina RCT participants was conducted. A linear regression with effects for intervention group, moderator, and interaction between intervention group and moderator was used to test each hypothesized moderator of dietary changes. Sobel-Goodman mediation test was used to assess mediating effects on dietary outcomes.

Results: Results varied by dietary outcome. Improvements in vegetable consumption were greatest for women who reported high spousal support at baseline. Women younger than age 30 were more likely to reduce added sugar consumption than older women. Participants who reported higher baseline perceived control were more likely to reduce fat consumption. No examined mediators were significantly associated with intervention effects.

Conclusion: Future interventions with pregnant Latinas may benefit from tailoring dietary goals to consider age, level of spousal support, and perceived control to eat healthy.

Trial registration: ClinicalTrials.gov NCT01584063.

Keywords: Latino; community health; community-based participatory research; diabetes; maternal and child health; race/ethnicity.

Conflict of interest statement

Conflict of Interest Statement: None of the authors have any conflicts of interest to report.

© 2015 Society for Public Health Education.

Figures

Figure 1

Conceptual Model for Mediators and Moderators of the Healthy MOMs Intervention *BMI-Body Mass Index **WIC/SNAP Benefits-Whether participant received the Special Supplemental Nutrition Program for Women, Infant and Children (WIC) or Supplemental Nutritional Assistance Program (SNAP) benefits

Figure 2

Variation in intervention effect for added sugar consumption by age Lower age associated with significant reduction in added sugar consumption. Grey bands indicate 95% confidence intervals. Interaction term: 03; p<.05>n= 218

Figure 3

Variation intervention effect for vegetable consumption by spousal support Lower reported support values indicate less baseline support from spouse. Grey bands indicate 95% confidence intervals. Interaction term: 11; p=.14 [for dichotomized outcome of low versus high support, interaction term: 31; p<.05>n= 208

Figure 4

Variation in intervention effect for total fat consumption by baseline perceived control to eat less fat Lower values on perceived control scale indicate less confidence by participant to eat less fat. Grey bands indicate 95% confidence intervals. Interaction term: −.07; p<.05>n= 215