In recent years, there has been a rapid evolution of mobile phone technologies for use in health promotion and disease prevention. The use of such technologies can allow for dissemination of information to large and varied populations. Innovative mobile intervention approaches used in health promotion include interactive voice response phone calls, use of cell phone applications (apps) and tailored Web-based interventions [1, 2]. With the widespread adoption and rapid advancement in the capacities of smartphones (mobile phones with an operating system capable of running applications), more technically advanced interventions, including multiple modes of interactivity and opportunities for engagement with consumers, patients, and beneficiaries of health programs, are now possible [3–5].

While mobile health (mHealth) is rapidly advancing with the advent of more powerful mobile phones, one of the phone’s most basic functions – text messaging – has been the most widely used and studied. Text messaging has been demonstrated to be a potentially powerful tool in effecting behavior change [6]. Recent examples of such prevention and health promotion interventions include smoking cessation, weight loss, depression and sexual health [7–10]. In the past, relatively few studies have been conducted to test the efficacy of mHealth programs as a channel for full-fledged health promotion programs, with most mobile programs focusing on reminder systems or similar limited behavioral cues to action [11]. However, this situation has begun to change, one sign of which is heightened interest in mHealth theory and development of behavior change models that incorporate the unique features of the mobile channel [5, 12].

In this paper, we report on a randomized pilot study of audience reactions and utilization of pre-natal and post-partum care promotion text messages delivered by the text4baby mHealth program. The text4baby program is designed for low-income women who are pregnant or have recently given birth, and need information and motivation to promote adoption and maintenance of healthy behaviors. This study was conducted exclusively among women who initially present for care at the Fairfax County, Virginia Health Department and then receive treatment from a local health care facility in the county. We randomized participants to enroll in text4baby and receive usual health care (intervention), or continue simply to receive usual care (control). We then conducted a behavioral survey of participants by telephone, and also use clinical and health services data collected by Fairfax County, Virginia Health Department and InovaCares clinic as part of their standard health assessments. These data sources were both used to evaluate text4baby outcomes.

The overall purpose of this study was to evaluate how well text4baby text messages are understood, whether they are trusted and liked, acted upon, and whether recommended behaviors are adopted by the target audience of low-income pregnant women and young mothers. The target population suffers from health disparities due to their socio-economic status and inadequate access to important pre-natal care and health information. Thus, sampling from this population offers an opportunity to gather evidence on the potential of text4baby to serve as a model program to help alleviate these disparities. It may also provide insight into the efficacy of the messages and aid the National Healthy Mothers, Healthy Babies Coalition (HMHB) in potential improvements to existing messages and creation of new messages or message delivery systems in the future.

The first specific aim of this study was to assess audience exposure, awareness, and cognitive and affective reactions to text4baby messages. The second aim was to identify direct effects of text4baby messages on maternal pre-natal care and related health attitudes, beliefs, and behavioral outcomes, including attending pre-natal care visits, eating a healthy diet, taking vitamins with folic acid, avoiding smoking and alcohol consumption, and related health promoting and risk avoidance behaviors.

The evolution from simple reminders and cues to action to more in-depth behavior change programs raises the importance of behavior change theory for mHealth. Recent studies have noted both that the relevance of existing behavioral theory, such as Social Cognitive Theory (SCT) and Theory of Planned Behavior (TPB), need to be examined and new models considered for their applicability to mHealth [5, 11, 13–15]. There is also a need for evaluation studies based on behavior change theory, as previous mHealth evaluations have not tested the theory-based mechanisms (mediators) of behavior change that have been shown to predict adoption and maintenance of health behaviors in previous research [13]. Evaluation models based on theory need to be developed and tested across multiple subject areas.

Text4baby is a text messaging service launched in February 2010 that delivers text messages (http://www.text4baby.org) to pregnant women and new mothers. Text4baby specifically targets traditionally underserved women facing health disparities. The intervention sends texts messages to offer immediate, “just-in-time” tips, with the goal of improving prenatal and postpartum health outcomes [13]. Text4baby aims to increase maternal expectations for health outcomes and to promote self-efficacy to utilize the health care system and make informed health care choices, outcomes that may not be regularly achieved in a population facing health disparities and with limited health care access. The program is based on traditional behavioral theories including Social Cognitive Theory (SCT), the Transtheoretical Model (TTM), and the Health Belief Model (HBM) [14, 16, 17]. Following elements of these theories, text4baby seeks to build self-efficacy to successfully utilize health care, improve health literacy, and increase expectations for successful pregnancy and new motherhood. It is designed to build knowledge and skills to manage one’s own health and prevent health risks by avoiding smoking, drinking, receiving recommended immunizations, and avoiding similar behavioral risk factors [18].

Figure 1 presents a preliminary model of text4baby that has been used to guide the development of program evaluation strategies.

We evaluated pre-natal text messages (new baby messages were not part of this study) delivered by the text4baby program in a randomized pilot study at two clinics that are part of the Fairfax County, Virginia Health Department. Women who initially presented for pre-natal care (first visit) at the Fairfax County, Virginia Health Department and then participate in the InovaCares clinic in Fairfax County were eligible for the study. A majority of the client population spoke Spanish as their primary language. Those who agreed to participate and provide verbal informed consent were randomly assigned into a text4baby exposure or to a no exposure (control) group. Both groups received standard Inova pre-natal counseling and care during study participation. Participants in the text4baby exposure group were directed to enroll in the text4baby message service by clinic staff implementing the evaluation study, in order to receive messages for the duration of their pregnancy (or until they dropped out of the program). No incentives were provided for participation in the study. Among womwn who presented at the clinics for prenatal services, 147 agreed to enroll in the study, 123 women responded to the baseline telephone survey (83.7% retention rate). Among the 123 enrollees, 90 completed a follow-up survey, resulting in a 73% retention rate.

Text4baby is an innovative mHealth program that has grown rapidly. Since its launch in February 2010, nearly 400,000 individuals had enrolled in the service at the time of this writing [25]. This widespread adoption suggests that the program has broad appeal and may represent a valuable health promotion model in the area of maternal and child health. It also raises the question of how effective such a program may be in changing health behavior and also how applicable it may be to other health domains.

This pilot study examined short-term effects of text4baby on attitudes and beliefs targeted by the program, and on immediate health promoting actions pregnant women may take as a result of receiving the messages. Text4baby follows a theory of behavior change illustrated in our conceptual model (Figure 1) that represents a combination of principles from SCT, HBM and the TTM. Thus this evaluation is one step toward validating a new theoretical approach to mHealth programs, one that calls for additional research and theoretical investigation in the field. Previous communication research suggests that targeted health communications delivered using validating messaging strategies may, by themselves, have small but statistically significant effects on subsequent health cognitions and behavior [26, 27]. The theory behind text4baby, then, is that beliefs targeted by the program’s text messages will have beneficial effects on those specific beliefs, which in turn will be associated with improvements related to health behaviors. This study examined the relationship between text4baby message exposure and beliefs as immediate program outcomes.

Overall, we found that text4baby exposure indeed was associated with an improvement in one important belief targeted by the messaging. Namely, mothers in the text4baby arm were nearly three times (OR = 2.73) more likely to believe that they were prepared to be new mothers compared to those in the no exposure control group. This may reflect the cumulative effect of multiple messages on a range of topics and the specific focus of those messages on being prepared for the challenges of pregnancy and motherhood and importance of being proactive to maintain good health. However, we did not observe any other effects of the intervention exposure on targeted beliefs.

Additionally, we found a strong effect of education level both on overall agreement (regardless of time) and a pre-post intervention effect on the belief that drinking alcohol during pregnancy will harm the unborn baby. Participants with a high school education or greater were more likely to hold this belief and, while only marginally significant, we observed several other effects of higher levels of education on beliefs targeted by the text4baby messages, as noted above. This may reflect the importance of literacy and comprehension on message effectiveness. Women who are more educated may be better able to process and make informed decisions as a result of text4baby messages. This suggests the potential importance of health literacy in mHealth interventions. This hypothesis should be explored in future studies.

This pilot study had some limitations that deserve attention. Limitations of the study include execution in a natural setting. Although precautions were taken to minimize contamination of subjects in terms of promotion of the text4baby program such as posters in the clinic, some control participants may have been exposed to the program due to its national popularity or through interaction with friends or family members enrolled to receive text messages. However, we have no direct evidence that this took place. In addition, the threat of selection bias is present since it is possible that women who wanted to enroll in the study may have been more motivated than others, or felt the need for more resources than other women.

Another limitation to the study was that we observed differences in the baseline versus follow-up samples due to attrition, with more WIC participants and fewer employed or in school at follow-up. This suggests a more economically disadvantaged sample at follow-up. While these differences should be treated with caution, one explanation is that participants may be at home as they prepare to give birth and may be more in need of WIC resources.

Another limitation was a smaller sample size than planned due to difficulty with recruitment. Anecdotally, reports from clinic staff who met with eligible women found that some had misgivings about enrolling in a service that involved providing mobile phone and other personal information such as their baby’s due date. This may be related to the fact that most women presenting for care were recent immigrants and may not have had complete immigration documentation, making the sharing of personal information seem potentially risky. Clinical intake staff also cited reasons for refusing to participate in the study, such as clients not having their own cell phone but rather using a spouses’ or partner’s phone, being concerned about using cell phone minutes to complete the baseline survey, and the requirement to complete a follow up.

As a result of the smaller than planned sample, we have relatively low statistical power. This reduces our ability to detect potential significant differences from baseline to follow up and between conditions and resulted in relatively wide confidence intervals for observed significant results. However, our sample was sufficient to conduct the planned statistical analyses and this limitation should be considered in the context of the study’s purpose as a pilot evaluation of text4baby. Despite limitations of the sample, the retention rate of 73% from baseline to follow-up was reasonable for a study with an economically disadvantaged sample of primarily non-English speaking immigrants [28].

This pilot experimental study found that text4baby participation improved a central belief targeted by the campaign – that the pregnant woman receiving text messages was prepared for motherhood. Education was an important factor in reaction to the text messages, suggesting the importance of health literacy in mHealth programs. Future research should examine the differential effects of messages with higher and lower levels of health literacy using experimental methods. The dimension of ‘preparation for motherhood’ should be examined in more depth in future text4baby studies. In particular, ‘preparation’ may reflect certain underlying factors that can be targeted more specifically in future messaging, and this hypothesis should be studied. Finally, large-scale randomized controlled trials should examine the potential for mediated relationships between effects of text4baby and other mHealth programs on health cognitions and subsequent behavior change over time.