The study team built a text-based developmental screening tool on the Text4baby technology platform based on Parents’ Evaluation of Developmental Status: Developmental Milestones (PEDS:DM), a validated paper- and Web-based screen [12]. The team then worked with the Maryland Department of Health and Mental Hygiene (MDHMH); Prince George’s County’s Women, Infants and Children (WIC) Program; and Infant and Toddlers Program (ITP) to pilot the tool with low-income mothers of infants aged 8-10 months. The MDHMH Institutional Review Board approved the study.

A number of validated tools are used to conduct developmental screening; most are paper-based tools and generally administered in a provider’s office, daycare center, or other site. The most current list of accepted tools is presented in the 2018 Technical Specifications for the Child Core Set of health quality measures for Medicaid and the Children’s Health Insurance Program [6]. AAP also provides links to validated screening tools and supporting documentation [5]. Although some of these tools have been adapted for online administration, to our knowledge, none are currently available in a text format.

Our study team selected its screening tool following a review of three validated tools [8] (Multimedia Appendix 1) that are also cited by AAP and Medicaid [5,6]. All three tools are characterized by the coverage of multiple mental, behavioral, and developmental domains; appropriateness for infants below the age of 12 months and through early childhood; consistency with AAP recommendations; use of parental responses based on their own observations; and accuracy and strong validation studies referenced in the review (>70% specificity and sensitivity) [8].

Of these three validated tools, the PEDS:DM is the most amenable to adaptation to an interactive text format. Each of the PEDS:DM questions for the target age is less than 160 characters long, so each question could be sent in a single text message (Table 1). Further, the PEDS:DM covers the six developmental domains (fine motor, expressive language, receptive language, gross motor, self-help, and social-emotional) with only six questions, each written at an elementary grade reading level [8,20]. In contrast, Ages & Stages [8] uses 30 questions written at the 3rd-12th grade level, a number of which exceed the 160-character limit of a text message and would require editing for length as well as reading level to be suitable for use in a text-based tool appropriate for the target audience.

The study team worked with PEDS:DM to incorporate the questions and responses (Table 1) and feedback (Table 2) in a text format, build the tool on the Text4baby technology platform, and check the text version for quality. Neither the wording of the PEDS:DM questions nor the scoring criteria were altered.

PEDS:DM is generally administered in a provider’s office by staff or self-administered on paper or online. The study team developed a plan with the ITP of Prince George’s County to ensure that follow-up was offered in person or by phone to mothers whose infants’ results indicated that they “may be behind.”

The study team was able to reach and recruit low-income mothers by partnering with the Maryland WIC program, an income-qualified program “designed to help low-income pregnant, postpartum, and breastfeeding women, infants, and children 5 years old or younger who are at nutritional risk” [21]. The Maryland WIC program defines low income as US $37,296 annually for a family of three people [21].

Staff in two WIC clinics in Prince George’s County offered a flyer about the study to mothers of infants aged 8-10 months who were visiting one of the clinics for services. Interested mothers were invited to a private area of the clinic where members of the study team described the study, answered questions, and advised the mothers that after completing the screening, they would receive a US $20 gift card and a gift bag with information about their baby’s development. The study team members then confirmed the eligibility of interested mothers to participate in the study. To be eligible, a mother needed to be the primary caretaker of an infant aged 8, 9, or 10 months; above the age of 18 years; able to speak and read English; and in possession of a mobile phone that was regularly used, including for texting. Eligible mothers filled out a form providing informed consent and were enrolled as participants in the study. After enrollment, the study team members collected information on participant and infant characteristics including age, gender, insurance status, and ethnicity/race (Table 3).

To measure usability, the study used objective data generated by the technology platform that reflected efficiency and effectiveness (Table 4). Study participants were asked to initiate the interactive screening tool by texting “DM” to the Text4baby short code 511411; this generated an automatic reply with the first of the PEDS:DM screening questions, asking the participants to respond by text message. Each time a participant texted a response to a question, the platform automatically sent a text message with the next question. After participants answered all six screening questions, a study team member asked them to review the questions and their responses. If they wished to make changes, study staff asked participants to text “DM” again to retake the screening questions.

Following any changes made, participants confirmed their answers by texting “RESULTS.” In response, they received a message listing areas where their infant appeared to be “doing well” and, if indicated, a second message with any areas where he/she “may be behind” (Table 2). The mothers then received a final text message with recommended actions. Following the screening, study team members also provided participants with a letter containing the results intended for the infants’ primary pediatrician from the Infants and Toddlers Program (under Part C of the Individuals with Disabilities Education Act) or a qualified child care provider, a US $20 gift card, and a gift bag that included a guide for parents on child development [22].

The Text4baby technology platform captured system data on measures of participant interaction. These data included a record of all questions and responses and date and time stamps for all outgoing and incoming texts.

To measure acceptability, beginning two weeks after the screening, study staff called all mothers and administered a phone survey (Table 5) to those who replied. This phone survey included questions related to participants’ experience using the text-based PEDS:DM and receiving feedback about their baby’s development via text.

Two subsets of mothers who participated in the phone survey were invited to attend one of two focus groups—one included seven mothers whose infants were “doing well” in all domains and the other included seven mothers whose infants “may be behind” in one or more domain. An independent evaluator facilitated the focus groups. Participants received a gift card to cover transportation and other costs. The aim of the focus groups was to provide context and insight into the usability and acceptability of the tool and learn about maternal actions following the screening (to be presented in a subsequent paper).

Usability and acceptability were examined among participants overall and by the developmental screening status of their infants. Applicable systems and phone survey data were used to assess each measure. In addition, observations made by mothers in the focus groups that related to usability and acceptability were included. A coding scheme was applied to qualitative data from interviews and focus groups to identify key themes.

Descriptive analyses were used to analyze quantitative systems and phone survey data. Where appropriate, quantitative analysis was performed using the Chi-square test. In many of the cases, there were too many zero cells, and therefore, statistical analysis could not be performed.

It was possible to take the existing validated PEDS:DM questions and program them on the Text4baby technology platform (Tables 1 and 2). Because the screening questions were already at a low reading level (second grade) and short (under 160 characters), it was not necessary to make any changes to their wording. Furthermore, because the response options were closed, simple, and clear (ie, “no,” “a little,” and “yes”), it was only necessary to add instructions (eg, “Reply 1 for no”). There were no changes in the thresholds for determining risk. The study team devised additional text messages to facilitate administration, deliver results, and provide appropriate feedback for the participants.

A total of 81 low-income mothers of infants aged 8-10 months were recruited and enrolled in the study: 93% (75/81) of the mothers reported that their infants were on Medicaid, 2% (2/81) had no insurance, 4% (3/81) had private insurance, and 1% (1/81) did not know her child’s insurance status (Table 3). Seventeen percent (14/81) of the mothers said that they had less education than a high school degree, 37% (30/81) had a high school degree, and 46% (37/81) had some college or higher education.

Nearly half of the mothers (49%, 40/81) indicated that they were Hispanic/Latina, 42% (34/81) identified as African American, and 5% (4/81) identified as white (non-Hispanic). In addition, 57% of the participants (46/81) listed English, 37% (30/81) listed Spanish, and 6% (5/81) listed another language as the first language spoken at home.

Of note, 15 mothers (19%) reported that their infant had been born prematurely compared to a statewide prematurity rate of 10.5% among all women and 12.5% among African American women in Maryland [23].

Most participants (91%, 74/81) reported using a mobile phone with internet access, and 9% (7/81) reported using a basic phone without internet access. Ninety percent of the participants (73/81) reported that they had a monthly texting plan that provided unlimited text messaging, 5% reported a monthly plan with limited texting (4/81), 1% (1/81) paid on a per-message basis, and 4% (3/81) did not know what their texting plan provided.

There were no statistically significant differences between subsets of these low-income mothers for any of the demographic and other characteristics except previous screening. Mothers who reported that their infant had been previously screened were significantly more likely to have infants who were “doing well” in comparison with those who did not report a previous screening (P<.02). Overall, 47% of the mothers reported that their infant previously received a similar screening (38/81); this proportion is higher than the national average and the Maryland statewide rate of 43% [1].

The assessment of usability of the screening tool focused on five objective measures of efficiency and effectiveness: initiation of the screening tool, completeness of responses to screening questions, time required, ability to receive results, and follow-up of infants who “may be behind” (Table 4).

Several mothers had connectivity issues with their phones inside one of the clinics but were able to connect by moving closer to a window. One of the mothers received a message from her carrier that the carrier would charge her for text messages. Since the study protocol specified that messages would be free, the study team lent her an alternative phone to use for the study.

All participants—mothers whose infants “may be behind” or were “doing well”—were able to text “DM” to the short code 511411 on their mobile phones (100%, 81/81). All were able to initiate the screening and successfully trigger the first question. In addition, all were able to trigger and enter one of the indicated responses to each of the six questions (100%, 81/81). A total of 79% (64/81) successfully submitted responses to all six questions on their first attempt. The remaining 21% (17/81) submitted final responses on the second or, in the case of one mother, third time. Three of these participants required additional time because of technology/connectivity issues. Four restarted the tool during submission of the six responses because they made an error in one or more responses.

After entering all responses to the last question, a study team member asked all participants to review their responses. Among the fourteen participants who changed one or more of their responses when they answered the questions for a second time, 86% (12/14) changed their response to Question 1 (“Poke”). Response to Question 2 (“Baby’s Name”) was the second most frequently changed: Half of those who changed their responses (7/14) changed their response to this question.

One focus group participant described her confusion about the meaning of “poke” as follows:

Additionally, although only three participants changed their answers to Question 6 (“Peek-a-boo”), some expressed concern about this question in the focus groups:

To follow-up with the 30 mothers whose responses indicated that their infants “may be behind,” the study team took a number of steps that will be described in detail in a forthcoming paper: All 30 mothers received a text message encouraging them to call the ITP. On the days when an ITP representative was present in the WIC clinic during the study, she met with any mother whose infant had one or more unmet milestones. She also attempted to call all these mothers to administer the follow-up survey. By the end of the study, the ITP representative had met or talked with all but two of the mothers (93%, 28/30).

Acceptability of the screening tool was assessed by a phone survey by using subjective measures of ease of use, usefulness, and satisfaction (Table 5). It was possible to reach and interview 80% of study participants (65/81). Almost all interview participants said that it was “Easy” (40%, 26/65) or “Very Easy” (58%, 38/65) to answer the six text message developmental screening questions; none said it was “Hard” or “Very Hard” (Table 5). As described by one focus group participant, “I have two kids and I’m on the phone or busy with kids. It’s easier to answer the questions on a phone than to have to talk on the phone.” A higher percentage of the participants whose infants were “doing well” said the text messages were “Very Easy” (70%, 28/40), compared to those whose infants “may be behind” (40%, 10/25). Because of the number of zero cells, it was not possible to perform statistical tests on these data.

Among all participants, the time required to complete the developmental screening (ie, the time between first texting “DM” and submitting the final response) was 4 minutes and 39 seconds on an average. All but three of the phone survey participants who provided an answer (95%, 62/65) felt that the amount of time it took to answer the six text messages was “the right amount of time.” As one mother explained, “The questions were easy and I could answer them quickly.”

All but one of the mothers surveyed said they would recommend the text-based screening to a friend (97.5%, 64/65), and all mothers reported that they wanted to answer screening questions again when their baby was older (100%, 65/65).

Mothers were asked to assess the overall experience of answering the questions and getting results by text: 80% of all mothers interviewed reported that it was “very good, it was helpful” (52/65) and 18% reported that it was “good, it was okay” (12/65). Only one mother reported that it was “average,” and no mother rated it as poor or unhelpful. When specifically asked to assess the value of obtaining results of the screening by text, almost all mothers responded that they liked receiving feedback by text “a lot” (57%, 37/65) or that it was “good, OK” (38%, 25/65). Although a lower percentage of respondents whose infants “may be behind” liked receiving feedback by text “a lot” or found it “good, OK” than the respondents whose infants were “doing well,” it was not possible to calculate statistics due to the number of cells with zero data.

The primary aims of this pilot study were to assess the usability and acceptability of a validated interactive text message-based tool for developmental screening of infants of low-income mothers as a strategy to make developmental screening more broadly available, particularly among low-income populations.

This pilot study found that it was feasible to create an interactive text-based screening tool based on a validated instrument, and low-income mothers of infants aged 8-10 months found the tool both usable and acceptable. The findings of this study are important because the ubiquity of mobile phones (100%) [10] and texting (95%) [11] among Americans aged 18-29 years creates the potential to make screening widely available to parents of infants, including those from low-income households and on Medicaid who are at a heightened risk of developmental delays especially in the early years.

Despite a long history of theory-based approaches for assessing the usability and acceptability of web interfaces, there is a paucity of literature on mHealth usability and the inherent challenges of mHealth usability assessments such as small screens and the lack of software that captures physical interactions with devices [19]. There are perhaps even greater challenges in capturing user experience in a text intervention. For example, users own a variety of devices from basic mobile phones to feature-rich mobile phones of varying sizes, and the screening tool may appear quite different depending on the device used. In addition, devices and platforms capture very limited data on interactivity beyond the time and content of interactive messages sent and received.

This study therefore focused on practical measures of performance reflecting actual use of the intervention and user assessments of their experience. The study found no differences in any of the measures of usability according to the infants’ developmental status or any of the demographic or socioeconomic characteristics. All mothers were able to respond to all questions and complete the screening (100%, 81/81) including the 21% of mothers who wanted to change one or more responses (17/81). Challenges due to poor mobile coverage in one of the clinics did not prevent participants from successfully completing the screening.

With regard to acceptability, mothers, including those who received a report that their infant “may be behind,” valued the tool as well as the experience of using it and receiving results by text. Almost all mothers ranked the experience “very good” or “good” and all but one said that they would recommend it to a friend. All mothers in the study expressed the desire to repeat the screening in the future when their infants were older.

There were several lessons learned that should be considered in future iterations and research. First, although the pilot study focused on infants aged 8-10 months, future research and implementation should extend the tool to cover additional ages recommended by AAP and Medicaid’s Child Core Set of health quality measures [4-6]. Second, words matter. The wording of one of the screening questions was associated with the highest error rates and should be reviewed and tested. Third, although there was no difference in the measures of usability for Spanish and English speakers in this pilot study, future iterations should offer a choice of language to the users. Fourth, the observation that mothers whose infants “may be behind” were even less likely to report a previous screening suggests that this approach could potentially reach and identify infants at the highest risk of developmental delay, who do not have a medical home and who might otherwise not be identified in a timely way. Fifth, a critical concern in conducting a developmental screening is how to refer mothers whose infants “may be behind” for further screening and, if indicated, diagnosis and treatment for their infants as required and supported by the Early and Periodic Screening, Diagnostic and Treatment benefit of Medicaid [6]. The ability of the ITP representative to reach 93% (28/30) of mothers whose infants “may be behind” in person in the clinic or by phone for possible follow-up was therefore an important aspect of the study process. Clearly, this is only the first, albeit necessary, step to ensure that at-risk infants receive the required diagnosis and appropriate treatment in a timely manner.

To our knowledge, this is the first study to use texting of a validated tool to conduct developmental screening in the United States and to assess such a tool with a low-income population largely enrolled in Medicaid. It is therefore important to incorporate the lessons learned in this study about usability and acceptability and test the effectiveness of this approach on a larger scale including in a randomized clinical trial [24]. Although many mHealth studies do not include an implementation component [15], this study was designed with a view toward large-scale implementation and evaluation.

The combination of broadly available mobile technology, a valid screen, and the partnerships put in place for this study—with Text4baby, the State of Maryland WIC program, and Prince George’s County ITP program—provides a potential model for scaling up and further evaluation of an approach to promote widespread access to developmental screening and potentially reach at-risk populations. Largescale mobile health programs such as Text4baby could make the developmental screening tool available to mothers enrolled in that program where follow-up is available from an infant’s pediatrician or an early intervention program such as ITP. To connect parents of infants who “may be behind” to follow-up, this study suggests that phone calls, in this study’s case, from the ITP to parents, following screening may be an effective method.

The text-based screening tool could also be used and evaluated in a medical home or other care setting. As noted in a recent review of mobile health applications to promote early language development, “m-Health could provide a natural extension of interventions and messages delivered within the primary care setting” [9]. For example, the waiting room staff could ask a parent to trigger the screening tool by sending a text message to a designated number. The parent could then receive and review the results immediately with the infant’s pediatrician or another provider.

In both cases, there could be advantages of embedding developmental screening in a broader texting program such as Text4baby. Parents could be sent additional text messages with information about resources for child development and tailored parenting tips as well as reminders to attend well-baby visits, a strategy that has been shown to be effective in increasing attendance rates [25].

Limitations of this pilot study include its relatively small sample size and primary focus on descriptive data. Participants recruited from two WIC clinics located near a major metropolitan area had higher educational levels than the United States average levels [26]. Maryland also has one of the highest rates of developmental screening in the United States [1]. Study participants may not reflect the overall population of low-income mothers of infants in this age cohort, given that more than half the mothers reported that their infants had had an earlier developmental screening. As part of explaining the purpose of the study and assuring that participant consent was “informed,” the study team likely raised awareness of developmental domains beyond the information provided in the screening messages. In addition, this pilot study did not include an independent test of validity of the text version as compared to a more traditional format.

The study has several important strengths. Because of the partnership with WIC and its clinics in Prince George’s County, the study was able to reach and recruit low-income mothers whose infants may be at elevated risk for developmental delays. Due to the partnership with ITP, it was possible to reach and offer follow-up to mothers whose infants “may be behind.” The study also focused on user experience and input in the early stages of development and testing of an innovative mHealth tool with lessons that should be incorporated in future implementation and research.

This pilot study addresses the low rates of developmental screening among low-income populations in the United States by investigating how to build on the dramatic growth in the coverage of mobile technology and the broad use of texting within this population.

The study concluded that a validated developmental screening tool delivered by text message to mobile phones is both usable and acceptable by low-income mothers of infants. The results and lessons learned in this study can inform further evaluation with larger sample sizes and at other recommended ages. It also offers insights for potential models for scalable implementation of validated developmental screening using text messaging to screen and support mothers of infants.

The combination of broadly available mobile technology and the partnerships put in place for this study with Text4baby, the State of Maryland’s WIC program, and Prince George’s County ITP program holds promise for scaling up and further evaluating a model to promote more widespread developmental screening.

This study contributes to the growing body of evidence supporting the feasibility as well as the effectiveness of using text messaging to address important health outcomes and disparities. Studies have documented the impact of text messaging programs on health knowledge, appointment attendance, vaccination compliance, and other health behaviors. The findings of this study extend mHealth research to support developmental screening and address services needed by at-risk populations.