key: cord-0974929-sritf8ve authors: King, Abby C.; Campero, Ines; Sheats, Jylana L.; Castro Sweet, Cynthia M.; Espinosa, Patricia Rodriguez; Garcia, Dulce; Hauser, Michelle; Done, Monica; Patel, Michelle L.; Parikh, Nina M.; Corral, Cecilia; Ahn, David K. title: Testing the effectiveness of physical activity advice delivered via text messaging vs. human phone advisors in a Latino population: The On The Move randomized controlled trial design and methods date: 2020-07-11 journal: Contemp Clin Trials DOI: 10.1016/j.cct.2020.106084 sha: 76217e5731c461f3e86f023cac09bd0f697b0431 doc_id: 974929 cord_uid: sritf8ve Abstract Physical inactivity is a key risk factor for a range of chronic diseases and conditions, yet, approximately 50% of U.S. adults fall below recommended levels of regular aerobic physical activity (PA). This is particularly true for ethnic minority populations such as Latino adults for whom few culturally adapted programs have been developed and tested. Text messaging (SMS) represents a convenient and accessible communication channel for delivering targeted PA information and support, but has not been rigorously evaluated against standard telehealth advising programs. The objective of the On The Move randomized controlled trial is to test the effectiveness of a linguistically and culturally targeted SMS PA intervention (SMS PA Advisor) versus two comparison conditions: a) a standard, staff-delivered phone PA intervention (Telephone PA Advisor) and b) an attention-control arm consisting of a culturally targeted SMS intervention to promote a healthy diet (SMS Nutrition Advisor). The study sample (N = 350) consists of generally healthy, insufficiently active Latino adults ages 35 years and older living in five northern California counties. Study assessments occur at baseline, 6, and 12 months, with a subset of participants completing 18-month assessments. The primary outcome is 12-month change in walking, and secondary outcomes include other forms of PA, assessed via validated self-report measures and supported by accelerometry, and physical function and well-being variables. Potential mediators and moderators of intervention success will be explored to better determine which subgroups do best with which type of intervention. Here we present the study design and methods, including recruitment strategies and yields. Trial Registration: clinicaltrial.gov Identifier = NCT02385591 Regular physical activity has been found to positively impact many of the most common chronic diseases in the U.S., yet approximately half of Americans engage in levels of aerobic physical activity that are insufficient for achieving many of these benefits [1] . This is particularly true for older, low-income, and Latino adults [2] , who have elevated rates of obesity, Type 2 diabetes, and other chronic conditions [3] , and often more limited access to appropriate health promotion programs [4] . The growth of tele-health programs to promote regular physical activity and other health behaviors provides a potentially convenient and accessible communication channel for delivering evidence-based physical activity advice and support to the American public [5] . This is particularly the case for Latino and other underserved groups, the majority of whom own mobile phones [6] and also report time and logistical constraints that may make it difficult to attend in-person classes or programs [4, 7, 8] . Short message service (SMS), also known as text messaging, is an especially prevalent and convenient form of communication that can be delivered via simple cell phone devices as well as smartphones to populations with a range of educational levels. The small number of mobile phone interventions to date that have included or focused primarily on text messaging generally have reported significant positive effects, relative to controls, on physical activity levels [5, 9] . However, few such interventions have been based on relevant behavioral theory or customized specifically for Latino adults, and most interventions have been less than 6 months in duration [9, 10] . The On The Move Trial represents among the first studies to systematically compare the effects of a culturally customized physical activity SMS advising program to a standard, staff-delivered physical activity phone advising program in Latino adults. A J o u r n a l P r e -p r o o f Journal Pre-proof second comparison arm-a culturally customized SMS intervention to promote a healthy diet-was also included to investigate any nonspecific effects of the innovative SMS delivery platform itself on physical activity levels. Given the relative lack of community-based clinical trials in the health promotion area that have specifically targeted midlife and older Latino adults [8] , the On The Move Trial also provides an opportunity to evaluate different recruitment channels of particular relevance to Latino adults. Phone-based interventions may be particularly suitable for midlife and older adults given their convenience (e.g., participants are not required to travel to a program location), customizability, and the fact that the majority of adults in this age group (i.e., 94% or higher in adults through age 64 years and 85% of adults ages 65 and older) use mobile phones [6] . The study design and procedures, including recruitment, intervention, and assessment procedures, constitute the major focus of this paper. The trial was conducted by the Healthy Aging Research and Technology Solutions (HARTS) laboratory at Stanford University School of Medicine. The Stanford University School of Medicine Institutional Review Board approved the study protocol for this trial. Study materials, including informed consent and recruitment, intervention, and assessment forms, were produced in English and underwent thorough translation into The major objective of this randomized controlled trial (RCT) is to compare two different communication modalities (human phone advising vs. interactive SMS advising) for delivering a theoretically derived PA program. The specific primary aim is to test whether a culturally appropriate 12-month physical activity intervention delivered via an interactive SMS platform is similar in effectiveness to a standard human telephone advisor intervention. The primary focus of the PA interventions is on walking-a convenient and popular form of physical activity, especially for insufficiently active adults [5] . An additional aim is to evaluate whether the interactive SMS platform is superior to an SMS attention-control arm in increasing physical activity levels. The study employs a single-blind, parallel randomized controlled design. Outcome assessors are blinded to intervention assignment and masked to prior assessment data for each participant. As part of the interventions, participants learn behavioral adoption and maintenance strategies throughout the year to foster increased autonomy, prevent relapse, and promote personal, proactive problem-solving around future challenges. In addition, to explore the potential for sustained maintenance of physical activity behaviors beyond the end of the 12-month intervention period, those participants beginning their study participation in the early stage of the trial period (N=167) complete an additional study assessment at 18 months. During this 12-to 18-month maintenance period, participants do not receive text messages or phone counseling sessions, but have the opportunity to reach out to study staff with any questions. The study has recruited eligible participants from five counties located in the greater San Francisco Bay Area, CA. Approximately 26% of the general population across J o u r n a l P r e -p r o o f Journal Pre-proof these five counties report being of Latino or Hispanic ethnicity [11] . Latino residents in the western U.S. come largely from Mexico and Central America [12] . Of those born outside the US, approximately 50% have lived here for 15 or more years. The following study eligibility criteria have been used to enroll study participants: (a) ages 35 years and older; (b) insufficiently active [13], i.e., engaged in less than 125 minutes/week of moderate intensity activity such as brisk walking over the past six months, based on initial study physical activity screening items (see below), followed by a final baseline physical activity determination using the Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire [14] , described further below; (c) able to safely engage in moderate forms of physical activities such as walking based on the Physical Activity Readiness Questionnaire (PAR-Q) [15] ; (d) able to read and understand English or Spanish sufficiently to provide informed consent and participate in all study procedures; e) planning to live in the area for the next twelve months; f) selfreported body mass index (BMI) ≥25 and ≤46 kg/m 2 , which was based on self-reported height and weight; g) willing to modify diet by increasing vegetables, fruits, and whole grains and reducing sugars and fats; h) not pregnant, planning to become pregnant in the next year or had a newborn in the past year; and i) self-identified as Latino or Hispanic. Individuals were deemed ineligible if they answered "yes" to any of the PAR-Q screening items, to ensure participant safety given that all interventions were being delivered remotely in the community. The study screen to determine physical activity status includes the following questions: 1) In the last three months have you regularly participated (at least two times per week) in any physical activity that has increased your breathing, such as aerobics, brisk J o u r n a l P r e -p r o o f Journal Pre-proof walking, dancing, swimming, or playing sports? If the participants answered "yes", they were asked to describe how many days per week and minutes per day they regularly exercised. These numbers are multiplied to calculate the total number of minutes per week. If the total number is 125 minutes or more, the individual is deemed ineligible. If the total number of minutes per week is reported as less than 125, then individuals are asked to report, in a typical or normal week over the past four weeks, the total number of minutes per week they engaged in dance, walking or hiking uphill, walking fast or briskly for exercise, and water exercises other than swimming. Individuals are deemed eligible if participation in the above exercises totals less than 125 minutes per week. A final determination of study eligibility based on physical activity status occurs at baseline using the full 27-item CHAMPS questionnaire to ensure that individuals' physical activity levels were commensurate with study eligibility criteria. To increase external validity, three complementary recruitment methods have been employed: geographically defined targeted mass mailings, cultural media-based promotion, and community outreach [16] [17] [18] . For the geographically defined targeted mass mailings, mailing addresses of residents in geographically defined Census block groups in the five target counties were accessed via a private mail service company and selected based on age and Latino ethnicity. Introductory bilingual letters describing the study and business reply cards were sent to households, along with a toll-free number to call and study website link to obtain further study information and undergo initial screening for study eligibility. The media promotional methods included university and other community email lists serving primarily Latino adults, social network platforms J o u r n a l P r e -p r o o f Journal Pre-proof such as Facebook, and study announcements placed in local Latino newspapers and on local Spanish television and radio stations. As part of community outreach activities, study information was placed at local community centers and was made available at local stakeholder events attended by bilingual study staff, such as health and resource fairs, back to school nights, Parent Teacher Association (PTA) meetings, local school council events, and parent group meetings, as well as local libraries, churches, local health clinics serving Latino adults, and local grocery stores [19] . Study participants and others who expressed interest in the study also were encouraged to refer others or share study information with others. The subject yield, with respect to the number of individuals who were enrolled in the trial by the different recruitment strategies across the 22-month study recruitment period, is summarized in Figure 2 in the Results section. Interested individuals could complete the eligibility screen, which took approximately 15 minutes to complete, via study website or phone call with study staff. If eligible based on the online screen, a staff member contacted the individual to verify eligibility and schedule an orientation session. Approximately 40% of participants completed the screen online. Those individuals judged to be initially eligible based on the telephone or web-based screen were invited to attend, depending upon where they lived, a group study orientation session at either Stanford University or a designated community center or similar location in their area. During the study orientation the study objectives and procedures were explained in further detail, all questions were answered, and interested J o u r n a l P r e -p r o o f Journal Pre-proof individuals were consented and scheduled for an individual baseline assessment visit held at the same location. Participants were given multiple options for attending the initial study orientation session, including holding an individual session for them if needed. If they did not show sufficient interest to attend that important initial session, they were not able to continue in the study given that informed consent was obtained in that session. Following the baseline assessment, those individuals found to be eligible and willing to enroll in the study were randomized to receive one of the three study interventions, followed by an initial introductory session (lasting about 30 minutes) for their designated intervention, typically in person but occasionally conducted by phone with research staff when an in-person meeting was unable to be scheduled. To promote full study understanding and sustained levels of participant retention across the 12-month intervention and assessment period, initial group-based study orientation sessions were employed following the telephone screening process and prior to baseline assessment to ensure that all individuals considering study participation were fully informed about the study objectives and expectations. This type of interactive pre-enrollment educational session has been linked with high levels of study retention in health behavior change trials lasting through 18 months [20] . The two physical activity interventions and nutrition-control intervention are based on theoretically derived cognitive-behavioral advice and support strategies used in the evidence-based Active Choices physical activity counseling program and similar to determine their own goals and intentions, and acknowledging personal difficulties encountered [33, 34] . Intervention content for the three arms is summarized in Table 1 . The two SMS interventions were developed in collaboration with CareMessage, a not-for-profit organization that builds mobile health solutions for underserved populations [35] [36] [37] [38] . Their patented, text message-based coaching technology enables providers to interact with patients/users through automated messages. CareMessage has content streams for physical activity and nutrition that are customizable to deliver specific messages, and, for the purposes of this study, can be varied with respect to the frequency and timing of delivery. Messages are interactive in that they ask the message receiver for answers to specific questions about goals (e.g., "Do you prefer to exercise in the morning or evening?"). To ensure that text messages were at an appropriate reading level (i.e., 3 rd -5 th grade), CareMessage and HARTS lab project personnel created a database of messages for which the word count was calculated automatically. Once the optimal word count was obtained, text messages were assessed for readability by inputting the text to readable.com online software to obtain the Flesch-Kincaid grade level [39] . Messages were revised until the optimal grade level threshold or lower was achieved. To ensure that all three interventions reflected local Latino cultural norms and values, the majority of project staff were members of the Latino community and/or had extensive experience in developing and testing communication messages and information for local Latino adults. They provided specific input during the study start-up J o u r n a l P r e -p r o o f phase to ensure that cultural norms and values were adequately reflected in all interventions (e.g., "familismo", i.e., importance of the family in all aspects of Latino culture). Prior to program finalization, multiple focus groups at local community centers with members of the target population also were conducted to obtain feedback on study information and messages, which were incorporated into the interventions. Study materials were translated using certified medical interpreters, and pre-tested with members of the target population to ensure participant understanding. Baseline to post-test assessments indicated that all but one of the participants J o u r n a l P r e -p r o o f increased physical activity over the 6-week period. These data indicated the acceptability of text messaging with this target population. To maintain intervention fidelity and quality assurance in the Human PA Telephone Advisor arm, trained staff members conduct regular quality control checks and activities as has been standard with the Active Choices telephone advising program [41, 42]. These activities include periodic review by senior intervention staff of Telephone Advisor logs and notes completed after each Advisor-participant session, review of the audiotapes that are collected (with participant consent) for all advising sessions, and random check-ins by study staff with study participants. Quality assurance for the two SMS Advisor arms includes regular monitoring of system performance and backup, participant response rates, and ongoing availability of a study helpline for participants to call for assistance in correcting any problems. A designated Stanford staff member has been in regular contact (twice a month or more frequently as needed) with the CareMessage Product team to ensure that any problems that occur could be resolved in a timely manner. basis throughout the study period to engage in mutual sharing and problem-solving of their experiences and challenges with their participants of relevance to ongoing intervention engagement and study retention. The primary outcome is change in total weekly walking minutes across the 12-month intervention period-which represents the most appealing and easy to do physical J o u r n a l P r e -p r o o f activity in this age group [5] . For all participants, physical activity is assessed at three time points: baseline, an interim assessment at six months, and at 12 months, with the 12 -month assessment considered the primary endpoint. To provide specific information on physical activity types, the validated Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire for midlife and older adults (interview format) [14, 43] , available in English and Spanish, is used to assess usual weekly minutes of different types and intensities of PA over the previous 4 weeks. Such validated selfreport instruments represent the most direct and reliable means for assessing the specific types of PA typically being targeted in interventions, given that device-based assessment tools (pedometers, accelerometers) capture more general movement levels beyond such purposeful PA behavior [44, 45] . CHAMPS variables have been consistently associated with device-based physical activity measures in prior studies [46, 47] , and the CHAMPS is the only PA instrument for older adults that correlates with both doubly-labeled water-measured PA energy expenditure and accelerometers [48] . It also has been shown to be sensitive to change with moderate-intensity PA programs such as Active Choices in a variety of community samples, including Latino adults [8, 22, 23, 42] . The proportion of each study arm meeting the national physical activity recommendations of at least 150 minutes/week of moderate-to-vigorous physical activity will also be evaluated [49] . Secondary physical activity outcomes of interest from the CHAMPS include moderateto-vigorous physical activity (MVPA) and total physical activity levels. Physical activity measurement using the CHAMPS is accompanied by the validated Actigraph® J o u r n a l P r e -p r o o f accelerometer (model wGT3X) as a secondary activity measure at the three major assessment time points [50] . The accelerometer provides device-based information related to overall physical activity amounts and intensity (though not the types of activities in which people engage). The accelerometry protocol from a large study of 860 older adults is being applied [44] . Wear-time validity is determined through applying the wear and non-wear time analysis and classification algorithms reported by Choi et al. [54] , and analysis and interpretation of the accelerometry data is based on our prior investigations and those of other aging adult populations [55] , including Copeland et al. [56] . Other secondary outcome variables of particular importance to aging Latino populations include the following: sedentary/inactive recreation behaviors, measured using a validated one-week recall survey responsive to change in older adults [57] ; body mass index (BMI), derived using standard clinical assessment protocols for height and weight [43] ; abdominal adiposity through waist circumference; resting blood pressure and heart rate, using standard protocols [43] ; physical function, assessed with the validated two-minute step test from the Senior Fitness Test protocol [58] ; [70] [71] [72] , this construct is assessed at baseline through self-reported number of years in the U.S., country of birth, and primary language spoken at home, which can be combined to reflect levels of acculturation [73] . 3) Perceived neighborhood built environments and neighborhood cohesion: In addition to the psychosocial characteristics described above, the nature of the neighborhood environments in which physical activity typically occurs can affect physical activity levels [44] . For older Latino adults, living in neighborhoods that enhance walkability as well as social contact and cohesion has been associated with greater physical activity and physical function [74, 75] . It follows that those with higher neighborhood walkability as well as social cohesion may do well irrespective of program assignment, whereas those lower in walkability and social cohesion might require the additional personalized "touch" possible with the Human Telephone Advisor. These constructs are measured at baseline with the Neighborhood Environment Walkability Scale (NEWS) [76] and the Neighborhood Social Cohesion scale [77] . J o u r n a l P r e -p r o o f To evaluate the potential mechanisms through which the interventions may exert their effects, putative mediators of intervention success are being collected at major measurement time points. They include self-efficacy for physical activity, social support, autonomous motivation (e.g., "I would exercise regularly because I feel that I want to take responsibility for my health") and other forms of motivational self-regulation drawn from Self-Determination Theory [78] , including external regulation (e.g., "I would exercise regularly because I feel pressure from other to do so"), introjected regulation (e.g., "I would exercise regularly because I would feel guilty or ashamed of myself if I did not do so"), and amotivation (e.g., "I really don't think about it") [79]. We posit that both PA interventions will positively influence these domains and improve PA as a result. Success using self-regulatory skills is being assessed with the Exercise Goal-Setting Scale, which captures goal-setting, self-monitoring, and problem-solving, along with the Exercise Planning and Scheduling Scale [80, 81] . Increased perceived support from family, friends, and the study advisor (human or SMS) is being assessed with the adapted Social Support for Exercise scale [82] . Autonomous motivation is being assessed with the Treatment Self-Regulation Questionnaire-Exercise [79]. To assess program use, the SMS Advisor in both SMS arms automatically quantifies, for each participant, the number of texts sent, number of texts with failed delivery, and number of texts with interactive components that did/did not receive a response. The Human Advisors track and record the number of calls attempted, number of calls successfully completed, and total length of calls for each participant. These J o u r n a l P r e -p r o o f metrics will be used to assess the rate of engagement with the respective advisor. To assess program acceptance, participants complete attitudinal measures including the bonding subscale of the Working Alliance Inventory, a 12-item computer program acceptability measure [63] . To assess safety, potential adverse events are captured using a standard form from our prior work [22]. Following stratification by gender, participants have been randomly assigned, using a computerized version of the Efron procedure [83] to one of the three study arms (Human PA Telephone Advisor, interactive SMS PA Advisor, interactive SMS Nutrition Advisor). Allocation concealment was in place during the randomization process to minimize selection and similar types of allocation bias. Assessment staff members are blinded to randomization assignment and masked to prior assessment data. Sample size estimates have been developed to test the study's primary question related to whether the automated SMS Physical Activity Advisor intervention results in 12-month weekly walking increases that are similar to those achieved in the Human Physical Activity Advisor intervention. Using a two-tailed 95% confidence interval on the effect size (Cohen's d), we will evaluate how the estimated true effect size compares with a critical effect size magnitude, set a priori, reflecting the threshold of clinical significance between the two treatments, ∆. Adequate power for clinical equivalence typically requires a sample size such that there is better than 90% probability that both upper and lower bounds of the confidence interval lie within a distance of ∆ from zero when the true effect size has magnitude greater than ∆. Powering the study for clinical J o u r n a l P r e -p r o o f equivalence typically provides sufficient power to test for superiority and noninferiority as well [84] . The effect size (Cohen's d) is the standardized difference between the rates of change in total walking minutes/week over the 12-month period. The critical value of Δ is based on a clinically meaningful difference between arms of 30 minutes of total walking minutes per week [5] and a within-arm standard deviation of 100 (i.e., ∆=.3). By enrolling approximately 140 subjects per physical activity arm and adjusting for potential attrition of 15%, a final sample size of 119 subjects per physical activity arm was determined to provide greater than 80% power to determine 12-month equivalency, as well as superiority and non-inferiority, between the two physical activity arms. Because standard imputation methods will be used for missing data in this intent-to-treat trial [85] , all enrolled participants will in actuality contribute to the study analyses. Multiple imputations will be performed by replacing missing 12-month values with a set of plausible values using the option of imputation by fully conditional specification methods (ten imputations will be done). Imputation results will then be combined [85, 86] . All reported outcomes will use intent-to-treat (ITT) methods. The data will be analyzed using mixed-effects linear regression models. Mixed-effects linear regression effectively addresses both missing data and early dropout in "intent-to-treat" analysis [87, 88] . Similar mixed-effects linear regression techniques will be used to address the secondary outcomes of interest, e.g., intervention impacts on clinical measures, physical function, and rated quality of life and well-being variables. We also hypothesize, as a secondary comparison, that both physical activity arms will produce significant increases from baseline to 12 months in physical activity relative J o u r n a l P r e -p r o o f to the attention-control (nutrition SMS) arm. Given that detecting a significant difference between physical activity arms and Control typically requires a smaller sample size than equivalency testing between the two physical activity arms, we have enrolled a smaller number of attention-control subjects (N=70). Given the lack of cost analyses for health promotion programs generally, and particularly with respect to e-Health programs in comparison to human advisor programs, collecting such information is strongly recommended [89, 90] . Planned analysis procedures to explore relative costs of the two programs are informed by cost evaluations employed by other investigators in the physical activity field as well as our prior work [91] [92] [93] . Program costs will be compared to outcomes (e.g., weekly walking minutes) to determine a dollar value of the program relative to the desired outcome [94] . This allows us to determine if the intervention that produces an equivalent or better outcome is less expensive to administer or, if not, to obtain estimates of the value of additional money spent (e.g., average number of dollars spent to obtain each additional minute of exercise per week). The economic trade-offs between the interventions are unclear and warrant a deeper investigation. Examination of people-related costs, scalability, and impact of the delivery channels will help inform the cost analysis. We view such analyses as preliminary, and will use them to evaluate the need for more detailed studies of the cost-effectiveness of these types of PA programs [89, 92] . Based on prior literature [91, 92, 95] , relevant costs that are tracked in each arm include the initial costs of developing/refining each intervention, and the costs of administering and participating in the programs. Tracked participation costs include frequency and length J o u r n a l P r e -p r o o f of the program advising communications and any related contacts. The time participants spend engaging in physical activity is an outcome and will not be counted among program costs. With respect to statistical power, cost analysis studies involving phone and automated physical activity advisors are lacking. A prior center-based physical activity study that was able to compare the cost-effectiveness of two active physical activity programs had a combined sample size for the two active intervention arms (n=235) that was smaller than the sample size in the current study [92] . Similar mixed-effects linear regression methods will be employed as described earlier. In addition to the above analyses, we plan to conduct exploratory moderator analyses following the procedures described by Kraemer et al. [96] and using mixedeffects linear regression models. The previously described moderator variables of interest (e.g., fear of negative evaluation, health literacy) will be centered and an interaction term calculated between the moderator variable and study arm assignment. Alpha will be set at .05 using a two-tailed test of significance for all interactions. Effect sizes will be calculated for moderation effects using Cohen's d formula [97] . Results from these analyses will inform future studies aimed specifically at a priori testing of specific moderators in this population to improve intervention response for nonresponder groups [93] . As per our prior mediation work [98, 99] , mediator analysis will follow the general procedures first described by Baron and Kenny [100] and informed by MacKinnon [101] . After confirming intervention success in changing physical activity, mixed effects linear regression will be used to evaluate if the interventions produced significant changes in the proposed mediators, described earlier, and if the proposed mediators were associated with significant increases in physical activity. Variables meeting these criteria will be included in formal tests of mediation, which will employ mixed effects linear regression modeling to assess whether treatment effect was attenuated after accounting for its indirect effects via the mediators. Complete mediation occurs when the direct effect of treatment in achieving improvements in physical activity vanishes when controlling for the putative mediator. The single mediator approach can be generalized to multiple-mediation scenarios provided that in step two of the Baron and Kenny approach, the putative mediators are regressed simultaneously on intervention group via a multivariate normal regression model, as per Preacher and Hayes [102]. The northern California counties which facilitates enrollment of a more heterogeneous and potentially generalizable study sample. As described, the especially high yield of the targeted mass mailings-a less frequently used recruitment strategy in communitybased research studies-suggests that this type of recruitment strategy may be particularly useful for Latino populations. A randomized controlled physical activity trial of Latino adults of an older age than the present sample found the same superiority of the targeted mass mailing approach relative to other recruitment strategies [93] . Similarly, at least one study has shown that personalized direct mailings can increase response rates for Latino adults relative to non-targeted approaches [17] . The planned comparative cost analysis affords additional information concerning the potential implementation and translatability of the two physical activity interventions in real-world contexts. J o u r n a l P r e -p r o o f The On The Move Trial provides a rigorous comparison of two remotely-delivered physical activity interventions that represent readily accessible, convenient, and potentially lower-cost alternatives to more standard in-person programs currently being offered in many U.S. communities. The increasing use and reach of mobile phones across the population, including lower income and underserved population segments, provides an excellent opportunity to leverage their use for physical activity promotion. 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