BACKGROUND: Dietary behaviors significantly influence health outcomes across populations. Unhealthy diets are linked to serious diseases and substantial economic burdens, contributing to approximately 11 million deaths and significant disability-adjusted life years annually. Digital dietary interventions offer accessible solutions to improve dietary behaviors. However, attrition, defined as participant dropout before intervention completion, is a major challenge, with rates as high as 75%-99%. High attrition compromises intervention validity and reliability and exacerbates health disparities, highlighting the need to understand and address its causes.
OBJECTIVE: This study systematically reviews the literature on attrition in digital dietary interventions to identify the underlying causes, propose potential solutions, and integrate these findings with behavior theory concepts to develop a comprehensive theoretical framework. This framework aims to elucidate the behavioral mechanisms behind attrition and guide the design and implementation of more effective digital dietary interventions, ultimately reducing attrition rates and mitigating health inequalities.
METHODS: We conducted a systematic review, meta-analysis, and thematic synthesis. A comprehensive search across 7 electronic databases (PubMed, MEDLINE, Embase, CENTRAL, Web of Science, CINAHL Plus, and Academic Search Complete) was performed for studies published between 2013 and 2023. Eligibility criteria included original research exploring attrition in digital dietary interventions. Data extraction focused on study characteristics, sample demographics, attrition rates, reasons for attrition, and potential solutions. We followed ENTREQ (Enhancing the Transparency in Reporting the Synthesis of Qualitative Research) and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and used RStudio (Posit) for meta-analysis and NVivo for thematic synthesis.
RESULTS: Out of the 442 identified studies, 21 met the inclusion criteria. The meta-analysis showed mean attrition rates of 35% for control groups, 38% for intervention groups, and 40% for observational studies, with high heterogeneity (I²=94%-99%) indicating diverse influencing factors. Thematic synthesis identified 15 interconnected themes that align with behavior theory concepts. Based on these themes, the force-resource model was developed to explore the underlying causes of attrition and guide the design and implementation of future interventions from a behavior theory perspective.
CONCLUSIONS: High attrition rates are a significant issue in digital dietary interventions. The developed framework conceptualizes attrition through the interaction between the driving force system and the supporting resource system, providing a nuanced understanding of participant attrition, summarized as insufficient motivation and inadequate or poorly matched resources. It underscores the critical necessity for digital dietary interventions to balance motivational components with available resources dynamically. Key recommendations include user-friendly design, behavior-factor activation, literacy training, force-resource matching, social support, personalized adaptation, and dynamic follow-up. Expanding these strategies to a population level can enhance digital health equity. Further empirical validation of the framework is necessary, alongside the development of behavior theory-guided guidelines for digital dietary interventions.
BACKGROUND: PROSPERO CRD42024512902; https://tinyurl.com/3rjt2df9.

BACKGROUND: Recruitment for clinical trials and large-scale studies is challenging, especially for patients with complex conditions like chronic pain. Email recruitment has the potential to increase efficiency, to reduce costs, and to improve access for underrepresented patient populations. The objective of this study was to examine the effectiveness, efficiency, and equitability of email versus postal mail recruitment for the Learning to Apply Mindfulness to Pain (LAMP) study, a three-site clinical trial of mindfulness-based interventions for chronic pain.
METHODS: Patients with chronic pain diagnoses were recruited from three United States Department of Veterans Affairs (VA) facilities using the VA electronic health record (EHR). Recruitment materials were sent using either postal mail (n = 7986) or email (n = 19,333). Patients in the email recruitment group were also mailed introductory postcards before any emails. Mailing addresses and email addresses were obtained from the EHR. Effectiveness was measured by the response rate of patients who logged into the secure LAMP study website. Efficiency was measured by the number of days from when the recruitment materials were sent to when patients logged into the LAMP portal as well as the estimated costs of each recruitment approach. To assess equitability, we examined whether email recruitment was less effective for underrepresented populations, based on demographic information from the EHR.
RESULTS: Effectiveness-unadjusted response rates were greater for email versus postal-mail recruitment (18.9% versus 6.3%), and adjusted response rates were over three times greater for email recruitment (RR = 3.5, 95% CI 3.1-3.8) based on a multivariable analysis controlling for age, gender, race, ethnicity, rurality, and site. Efficiency-email recruitment had a significantly lower mean response time (1 day versus 8 days) and a lower cost. Equity-email recruitment led to higher response rates for all subpopulations, including older, non-White, Hispanic, rural, and female Veterans.
CONCLUSIONS: Email recruitment is an effective, efficient, and equitable way to recruit VA patients to large-scale, chronic pain clinical trials.
BACKGROUND: Clinical Trial Registration Number: NCT04526158. Patient enrollment began on December 4, 2020.

UNASSIGNED: Physician clinical educators play important roles in teaching, providing feedback, and evaluating trainees, but they often have variable preparation and competing demands on their time that make universal participation in workshops, seminars, or short courses designed to foster these skillsets inefficient or impossible.
UNASSIGNED: We designed and implemented a 52-week synchronous curriculum designed to address faculty opportunities to improve teaching skills, feedback for residents and medical students, and evaluation skills, which were delivered using marketing automation tools, including text messaging and email. We evaluated the programmatic impact and feasibility of using the implementation science framework.
UNASSIGNED: Over a 104-week evaluation period, there were at least 10,499 total content impressions and 4558 unique recipients, indicating the significant reach of this program to approximately 120 faculty members. Faculty engagement with continuing education materials remained stable or increased over the 2-year evaluation period, indicating that programs like ours can have sustainable impacts. Resident evaluations of faculty across the six key domains also improved after the implementation of the program.
UNASSIGNED: Our experience with digital marketing tools reflects that they can be used to deliver impactful curricular content to faculty for continuing educational purposes and that faculty can use these resources in a sustainable way. However, because of the incomplete reach with any single communication, this type of content delivery is not appropriate for isolation as a material of critical importance. More research is needed to identify the best practices and additional education-related uses of this technology.

Within teletherapy, email interventions have been studied scarcely. For this reason, this exploratory study aims to characterize the assistance provided by email in a university telepsychology service and to compare the data with the assistance provided by telephone in the same service and period. For this purpose, the records of 81 users assisted via email during the COVID-19 pandemic lockdown in Spain were analyzed. The data were compared with those of the 338 users assisted by telephone in the same period. Despite its many limitations, results indicate high satisfaction with the email modality. Users express that they prefer a preference for using email when they do not feel safe in other ways. We found a lot of variation between the number of emails exchanged and the days that each case was active. Additionally, differences were found with telephone users in aspects such as age (email users being younger) and in a depression screening (email users scoring more positively). This study concludes on the high potential of this channel for the application of certain techniques (e.g., psychoeducation) or for people with certain characteristics.

Email etiquette is an important skill, especially in professional settings. Research demonstrates that undergraduate students follow email rules when given written instructions plus an example. The purpose of the present study was to evaluate the effects of computer-based email instruction on undergraduate students\' email etiquette and to assess the social validity of that instruction. The email instruction package was delivered through an online learning management system and consisted of written instructions plus a model, a quiz, and quiz feedback. We measured email etiquette by scoring emails from course assignments using a checklist. The instruction package produced a replicated increase in mean email checklist scores across two sections of introductory psychology, and checklist scores were elevated when participants sent emails in a novel context. The results of the social-validity assessments suggest that the goals were important, the procedures were acceptable, and there were meaningful improvements in email etiquette for some participants.

BACKGROUND: Current online interventions dedicated to assisting individuals in managing stress and negative emotions often necessitate substantial time commitments. This can be burdensome for users, leading to high dropout rates and reducing the effectiveness of these interventions. This highlights an urgent need for concise digital activities that individuals can swiftly access during instances of negative emotions or stress in their daily lives.
OBJECTIVE: The primary aim of this study was to investigate the viability of using a brief digital exercise, specifically a reflective questioning activity (RQA), to help people reflect on their thoughts and emotions about a troubling situation. The RQA is designed to be quick, applicable to the general public, and scalable without requiring a significant support structure.
METHODS: We conducted 3 simultaneous studies. In the first study, we recruited 48 participants who completed the RQA and provided qualitative feedback on its design through surveys and semistructured interviews. In the second study, which involved 215 participants from Amazon Mechanical Turk, we used a between-participants design to compare the RQA with a single-question activity. Our hypotheses posited that the RQA would yield greater immediate stress relief and higher perceived utility, while not significantly altering the perception of time commitment. To assess these, we measured survey completion times and gathered multiple self-reported scores. In the third study, we assessed the RQA\'s real-world impact as a periodic intervention, exploring engagement via platforms such as email and SMS text messaging, complemented by follow-up interviews with participants.
RESULTS: In our first study, participants appreciated the RQA for facilitating structured reflection, enabling expression through writing, and promoting problem-solving. However, some of the participants experienced confusion and frustration, particularly when they were unable to find solutions or alternative perspectives on their thoughts. In the second study, the RQA condition resulted in significantly higher ratings (P=.003) for the utility of the activity and a statistically significant decrease (P<.001) in perceived stress rating compared with the single-question activity. Although the RQA required significantly more time to be completed (P<.001), there was no statistically significant difference in participants\' subjective perceived time commitment (P=.37). Deploying the RQA over 2 weeks in the third study identified some potential challenges to consider for such activities, such as the monotony of doing the same activity several times, the limited affordances of mobile phones, and the importance of having the prompts align with the occurrence of new troubling situations.
CONCLUSIONS: This paper describes the design and evaluation of a brief online self-reflection activity based on cognitive behavioral therapy principles. Our findings can inform practitioners and researchers in the design and exploration of formats for brief interventions to help people with everyday struggles.

Background: Social media networks such as Facebook, Twitter, WhatsApp, and YouTube are among the most commonly used social networks among people. If used properly, they can contribute to enhancing individual knowledge and scientific values. Aim: The study aimed to investigate the use of social media networks for healthy nutritional practices among deaf and hearing students. Methods: The sample of the study consisted of 103 students (50 deaf and 53 hearing). The researchers used a descriptive approach and adopted a questionnaire for data collection. Results: The findings of the study showed that the use of social media networks for healthy nutritional practices among deaf and hearing students was at a moderate level. However, there were statistically significant gender differences in the average responses of deaf and hearing students in the use of social media networks for healthy nutritional practices. For the status of students (deaf and hearing students), there were statistically significant differences in the average responses to the use of social media networks for healthy nutritional practices. Conclusion: Social media networks play an important role in raising awareness and promoting healthy nutrition practices for both deaf and hearing students.

Web- or app-based digital health studies allow for more efficient collection of health data for research. However, remote recruitment into digital health studies can enroll nonrepresentative study samples, hindering the robustness and generalizability of findings. Through the comprehensive evaluation of an email-based campaign on recruitment into the Health eHeart Study, we aim to uncover key sociodemographic and clinical factors that contribute to enrollment.
This study sought to understand the factors related to participation, specifically regarding enrollment, in the Health eHeart Study as a result of a large-scale remote email recruitment campaign.
We conducted a cohort analysis on all invited University of California, San Francisco (UCSF) patients to identify sociodemographic and clinical predictors of enrollment into the Health eHeart Study. The primary outcome was enrollment, defined by account registration and consent into the Health eHeart Study. The email recruitment campaign was carried out from August 2015 to February 2016, with electronic health record data extracted between September 2019 and December 2019.
The email recruitment campaign delivered at least 1 email invitation to 93.5% (193,606/206,983) of all invited patients and yielded a 3.6% (7012/193,606) registration rate among contacted patients and an 84.1% (5899/7012) consent rate among registered patients. Adjusted multivariate logistic regression models analyzed independent sociodemographic and clinical predictors of (1) registration among contacted participants and (2) consent among registered participants. Odds of registration were higher among patients who are older, women, non-Hispanic White, active patients with commercial insurance or Medicare, with a higher comorbidity burden, with congestive heart failure, and randomized to receive up to 2 recruitment emails. The odds of registration were lower among those with medical conditions such as dementia, chronic pulmonary disease, moderate or severe liver disease, paraplegia or hemiplegia, renal disease, or cancer. Odds of subsequent consent after initial registration were different, with an inverse trend of being lower among patients who are older and women. The odds of consent were also lower among those with peripheral vascular disease. However, the odds of consent remained higher among patients who were non-Hispanic White and those with commercial insurance.
This study provides important insights into the potential returns on participant enrollment when digital health study teams invest resources in using email for recruitment. The findings show that participant enrollment was driven more strongly by sociodemographic factors than clinical factors. Overall, email is an extremely efficient means of recruiting participants from a large list into the Health eHeart Study. Despite some improvements in representation, the formulation of truly diverse studies will require additional resources and strategies to overcome persistent participation barriers.

BACKGROUND: Postsecondary students need to be able to handle self-regulated learning and manage schedules set by instructors. This is particularly the case with online courses, as they often come with a limited number of social reminders and less information directly from the teacher compared to courses with physical presence. This may increase procrastination and reduce timeliness of the students. Reminders may be a tool to improve the timeliness of students\' study behavior, but previous research shows that the effect of reminders differs between types of reminders, whether the reminder is personalized or general, and depending on the background of the students. In the worst cases, reminders can even increase procrastination.
OBJECTIVE: The aim of this study was to test if personalized email reminders, as compared to general email reminders, affect the time to completion of scheduled online coursework. The personalized reminders included information on which page in the online material the participants ought to be on at the present point in time and the last page they were on during their last session. The general reminders only contained the first part of this information: where they ought to be at the present point in time.
METHODS: Weekly email reminders were sent to all participants enrolled in an online program, which included 39 professional learners from three East African countries. All participants in the Online Education for Leaders in Nutrition and Sustainability program, which uses a question-based learning methodology, were randomly assigned to either personalized or general reminders. The structure of the study was AB-BA, so that group A received personalized reminders for the first unit, then general reminders for the rest of the course, while group B started with general reminders and received personalized reminders only in the third (and last) unit in the course.
RESULTS: In total, 585 email reminders were distributed, of which 390 were general reminders and 195 were personalized. A Bayesian mixed-effects logistic regression was used to estimate the difference in the probability of being on time with one\'s studies. The probability of being on time was 14 percentage points (95% credible interval 3%-25%) higher following personalized reminders compared to that following general reminders. For a course with 100 participants, this means 14 more students would be on time.
CONCLUSIONS: Personalized reminders had a greater positive effect than general reminders for a group of adults working full-time while enrolled in our online educational program. Considering how small the intervention was-adding a few words with the page number the student ought to be on to a reminder-we consider this effect fairly substantial. This intervention could be repeated manually by anyone and in large courses with some basic programming.

Vasovagal reactions (VVRs) are one of the primary reasons for people to stop donating blood. The aim of this study was to evaluate the impact of newly developed online communications on the rate of return of whole-blood (WB) and plasma donors who experienced a VVR.
First-time and experienced WB and plasma donors who had a VVR without a loss of consciousness in the previous 3 days were randomly allocated to receive (a) an SMS sent 1-4 days post-VVR (n = 2303), (b) an email sent 6-10 days post-VVR (n = 2360), (c) both the SMS and the email (n = 2248), or (d) business-as-usual donor retention communications (control; n = 2557). Donation data were extracted to determine subsequent donation attempts.
For return within 3 months, WB donors in the Email Only condition had significantly increased odds of returning (OR: 1.26, 95%CI: 1.01-1.56). Subgroup analysis within WB donors showed increased odds of return for women sent the SMS and Email (OR: 1.50, 95%CI: 1.14-1.96) or the Email Only (OR: 1.44, 95%CI: 1.10-1.89), and for first-time donors sent the Email Only (OR: 1.48, 95%CI: 1.07-2.05). At 6 months, only first-time WB donors in the Email Only condition had significantly increased odds of returning (OR: 1.30, 95%CI: 1.01-1.69). No significant effects of the intervention were found for immediate or intermediate return for plasma donors.
Sending an email addressing common donor concerns regarding VVRs increases WB donor retention, but additional strategies are needed for the effects to last and to retain plasma donors.