Dose and timing of text messages for increasing physical activity among pregnant women: a randomized controlled trial

Abstract

Text4baby (T4b), a free nation-wide mobile health information service, delivers health-related text messages (SMS) to pregnant women. The objective of this study was to determine the effectiveness of physical activity (PA) specific SMS to improve PA in pregnant women (vs standard T4b) and the most effective dose/timing of PA-specific SMS to improve PA. Pregnant women (N = 80) were randomized to one of four groups that differed in frequency and time of SMS. The Fitbit™ Flex measured PA. Data were analyzed using mixed model analyses. There were no increases in PA regardless of frequency or time. Those that received six PA SMS/week had greater decreases in activity and greater increases in sedentary time. SMS may not be a "potent" enough strategy to improve PA. Future studies should explore a modified focus on behavior change (e.g., decrease sedentary activity, increase light activity) and incorporate SMS as part of a multi-level approach with other evidence-based strategies.

Get the message? A scoping review of physical activity messaging

“…Qualitative research supports message delivery through credible sources such as HCPs in pregnant women [133]. A randomised controlled trial found that pregnant women who received 6 PA messages/week had greater decreases in PA and increases in sedentary time than those who received fewer messages [136].…”

A Comprehensive Evaluation of a Home Visitation Program Model's Prenatal Physical Activity Curriculum Modules Delivered Primarily to Low-income Women

“…At present, 10 intervention studies, where the primary intent was to improve prenatal PA levels, provide information about participant income. [26][27][28][29][30][31][32][33][34][35] Given the inconsistencies in reporting income levels, these studies are compared in the following paragraphs using three income classifications: low income (less than $25,000), middle income ($25,000-$49,999), and high income ($50,000 or more). This classification scheme was based on the household income groupings used in PRAMS (i.e., < $10,000; $10,000-$24,999; $25,000-$49,999; and > $50,000).…”

“…1 Over half of the studies (6/10) had samples which primarily represented middle-to highincomes. 26,29,[31][32][33]35 In addition, one study's sample could not be classified due to the way it operationalized the participants' income (i.e., 62% with an income below $100,000 and 38%…”

“…[23][24][25] Therefore, this researcher identified and examined 10 prenatal PA intervention studies that reported information on income and had a primary intent to improve prenatal PA levels post-intervention. [26][27][28][29][30][31][32][33][34][35] Six of these studies [26][27][28][29][30][31] were in at least one of the earlier systematic reviews by Craike and colleagues, 25 Currie and colleagues, 24 and Pearce and colleagues. 23 Also, one study 34 was excluded from this review due to the way it operationalized income, as described in paragraph two of the prior section.…”

“…The six studies with primarily middle-to high-income participants correspondingly had predominantly White and/or Caucasian participants. 26,29,[31][32][33]35 In comparison, the three studies with primarily or exclusively low-income participants had predominantly Hispanic participants, at 40.5%, 55%, 30 and 60.2% of the study samples. Among these three studies, the strength was a focus on a less active subpopulation (i.e., compared to Blacks and Whites).…”