Evaluation of a Text Messaging Intervention to Promote Preconception Micronutrient Supplement Use: Feasibility Study Nested in the Healthy Life Trajectories Initiative Study in South Africa

Background: Social messaging strategies such as SMS text messaging and radio are promising avenues for health promotion and behavior change in low- to middle-income settings. However, evidence of their acceptability, feasibility, and impact in the context of young women's health and micronutrient deficiencies is lacking. Objective: This study aimed to evaluate the feasibility of an automated 2-way text messaging intervention nested in an ongoing preconception health trial, the Healthy Life Trajectories Initiative (HeLTI; HeLTI Bukhali) in Soweto, South Africa. Second, we aimed to evaluate the acceptability of a health promotion radio serial, which aired concurrently in the region. Methods: In this feasibility study, 120 participants enrolled in HeLTI Bukhali between November 2020 and February 2021 received the 6-month 2-way text messaging intervention. Quantitative and qualitative data on intervention acceptability, usability, interaction, perceived benefit, and fidelity were collected during 5 focus group discussions (FGDs) and from study data logs. During the FGDs, data were collected on the acceptability of the radio serial. Following the text messaging intervention, capillary hemoglobin levels were assessed, and a participant questionnaire provided information on adherence and attitudes toward supplements. The text messaging control group comprised the first 120 women recruited from November 2019 to February 2020, who received the Bukhali intervention but not the text messages. Statistical significance testing and a linear mixed model were used for indicative effect comparisons between the text message-receiving and control groups. Results: The text messaging intervention was found to be acceptable and to have perceived benefits, including being reminded to take supplements, gaining knowledge, and feeling supported by the study team. The use of the 2-way text messaging reply function was limited, with only a 10.8% (13/120) response rate by week 24. Barriers to replying included a lack of interest or phone credit and technical issues. Regarding the indicative effect, participants receiving the text messages had higher self-reported adherence at follow-up than the text messaging control group (42/63, 67% vs 33/85, 39% taking supplements every time; P=.02), and altitude-adjusted hemoglobin increased more between baseline and follow-up in the SMS text message-receiving group than in the text messaging control group (1.03, 95% CI 0.49-1.57; P<.001). The radio serial content was acceptable, although few participants reported exposure before the FGD. Conclusions: Women reported that the text messaging intervention was useful and described the benefits of receiving the messages. Examination of hemoglobin status indicated a promising beneficial effect of text messaging support on adherence to micronutrient supplementation, requiring further exploration through randomized controlled studies. Health promotion through radio and text messages were both found to be acceptable, although more research into the radio serial reach among young women is needed.