Dissertations and Theses

Date of Degree


Document Type


Degree Name

Doctor of Philosophy (Ph.D.)


Community Health and Social Sciences


Emma Tsui

Committee Members

Terry T-K Huang

May May Leung

Katarzyna Wyka

Subject Categories

Communication Technology and New Media | Community Health and Preventive Medicine | Graphic Communications | Health Communication | Public Health | Social and Behavioral Sciences


interactive technology, ehealth, mhealth, childhood obesity, urban population, minority population


Background: Web-based/mHealth interventions may be an engaging approach to promote positive dietary-related behaviors among parents of youth at-risk for childhood obesity. Importantly, childhood obesity research highlights the role of parents as a key support mechanism in improving child dietary outcomes. Intervention INC is a childhood obesity intervention that comprises a unique, interactive web-based child nutrition comic aimed at improving dietary behaviors among urban Black/African American (AA) and Latino preadolescents, and also weekly online parent newsletters (with feeding tips, healthy printable recipes, links to coupons to support healthy eating/feeding and health-promoting local/community events, and access to the child nutrition comic) to promote healthy parent feeding practices and the home food environment. To conduct a comprehensive evaluation of technology-optimized interventions, it is important to analyze not only key outcome measures, but also participant usage of and user experiences with the intervention. Intervention INC was evaluated in a pilot two-group randomized controlled trial (RCT). Presented here are three separate but interrelated studies examining data collected from parent/guardian participants as part of this pilot RCT. Specifically, the three studies focused on assessing: 1) parent/guardian usage of Intervention INC, 2) their experience with Intervention INC, and the 3) impact of Intervention INC on parent feeding practices and the home environment.

Methods: Parents/guardians (n=89) of Black/AA and Latino children ages 9-12 were randomized to receive Intervention INC (n=45) or a comparison web-based tool (n=44) over a 6-week intervention period. At the baseline visit (T1), parents were setup with an account on their web-based tool and received training. At T1, participants completed at online survey to assess baseline demographic data and outcomes measures (parent feeding practices and the home food environment). Between T1 and T3 (intervention end of 6-weeks post-baseline), individual user usage data was auto generated via a custom-built platform that captured every action (“click”) by participants including unique URLs and click date/time. At T3, qualitative assessment of usability, feasibility, and acceptability of the intervention was conducted via semi-structured interview by phone or in-person, as well as online survey assessment of post-intervention outcomes measures). User log data were analyzed to assess adherence to weekly use, total usage by week/day and by specific content, patterns of individual use, and user types. Interviews were analyzed using a directed content analysis approach combined with rapid evaluation techniques and charting matrices to facilitate identification of patterns/themes, divergent perspectives, as well distinguish between user types established based on user log data. Outcome survey data were analyzed using mixed model methodology (with intent-to-treat approach) with repeated assessments (timepoints T1, T3, and T4), group (experimental or comparison), and time by group interaction.

Results: Key characteristics of the 89 participants included: mean age 40.8±8.8 years; 94.4% female; 50.6% Black/AA and 39.3% Hispanic/Latino; 73.0% U.S. born; 32.6% with HS/GED education or less; 46.1% reporting “single” for marital status, 67.4% with a household income below $40,000 and 60.7% of households participating in SNAP, and 41.6% with a perceived health rating as “excellent” or “very good.” Baseline characteristics of parent/guardian participants did not differ between groups.

In assessing parent usage of Intervention INC (specifically among experimental group participants as they were allocated the web-based tool with all components including the child nutrition comic), adherence to weekly use of the tool decreased after Week 1 (100% viewing the web-based newsletter and 91% the child nutrition comic in Week 1; an average of 44% returning to view newsletter content and 32% returning to view comic content over Weeks 2-6). Total weekly usage was highest in Week 3 and lowest in Week 5; total daily usage was highest on Day 1 of each week when an email/text reminder was sent to participants. Few participants accessed the weekly coupon, event link, or “print recipe” option (weekly average of 30%, 20% and 1% of participants, respectively). Identified user types were: “early dropouts” (25% of participants, accessing tool 1 of 6 weeks), “infrequent users”, (25%, accessing 2 of 6 weeks), “occasional-users” (20%, accessing 3-4 of 6 weeks), and “frequent users (30%, accessing 5-6 of 6 weeks). Occasional and frequent users were on average older than early dropouts or infrequent users, and frequent users had the highest proportion of participants identifying as Hispanic/Latino, born outside the U.S., and participating in SNAP.

In assessing parent user experiences with Intervention INC (also specifically among experimental group participants), most participants reported accessing Intervention INC at least once per week and on different devices, prompted by the weekly notifications of new available content. Few usability issues were described except for those who needed a password reset or had slow/unreliable internet access. All parents responded very positively to the newsletters describing it as informational, easy to use, and motivating. However, while parents generally liked the provided recipes and coupons, few reported trying the recipes (due to lack of time or ingredients) or using the coupons (not interested in the featured item or unclear what stores accepted them). Highlighted community events in the newsletters were largely not attended (due to scheduling conflicts or inconvenient locations) though many appreciated that they were low-cost/free and family friendly. Most parents reported viewing at least one comic chapter (out of six) and highlighted their child’s positive responses to the comic. For some, the comic facilitated conversations related to healthy eating. Additionally, some feedback differed by number of weeks accessed, age, race/ethnicity, U.S. vs. non-U.S. born, education, and marital status.

In assessing the impact of Intervention INC (included all participants from both experimental and comparison groups), no significant impact on parent feeding practices and the home food environment was found between Intervention INC versus a comparison web-based tool. Observed outcome measures did not differ significantly between groups at each individual timepoint or within groups between timepoints, except for within-group changes from T1 to T4 in feeding practices among experimental group participants (p=.027). Effect sizes (using observed outcome means) between- and within-groups were small (d < 0.3) for both outcome measures across timepoints. Unadjusted mixed model analysis showed no significant difference in feeding practices (time by group interaction, p=0.747) or the home food environment (time by group interaction, p=0.871) between groups across the three timepoints. At post-intervention (T3), the experimental and comparison group model estimated mean scores for feeding practices were 117.18 (95% CI: 113.04-121.31) and 116.36 (95% CI: 112.26-120.46), respectively; model estimated mean scores for the home environment were 27.15 (95% CI: 26.40-27.90) and 27.03 (95% CI: 26.24-27.82), respectively.

Conclusion: Findings did not support the potential impact of this intervention on measures of parent feeding practices and the home food environment (although it is important to note that the pilot RCT parent study was designed to evaluate the impact of the intervention on dietary-related measures among preadolescent participants). However, an analysis of usage data showed different patterns of use and adherence to using the tool. Further, an analysis of qualitative data collected post-intervention highlighted generally high perceived usability, feasibility, and acceptability of the tool among participants, but also important differences in user experiences and facilitators/barriers to engagement with the tool and promoted activities by different sub-groups in the study population. The methodology implemented in this research is representative of the level of rigor needed to comprehensively evaluate digital health interventions and technologies. Findings from this research have implications for future enhancements to Intervention INC to promote deeper engagement and increase the potential impact of the intervention. Learnings are also relevant for future research in parent-focused interventions for childhood obesity (especially among minority, low-income populations), as well as broader mHealth behavior change interventions.



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