Abstract MP10: Text Messaging to Reduce Inactivity Using Real-Time Step Count Monitoring in Sedentary Overweight Females
Authors: Ouyang Pamela , Stewart Kerry J , Bedra McKenzie E , York Sarah , Valdiviezo Carolina , Finkelstein Joseph 
Published: July 2021

Introduction:
Prolonged periods of of inactivity are associated with higher CV morbidity independent of level of activity. Work and lifestyle choices today are associated with long periods of sitting, e.g. computer or screen watching. Wearable activity monitors such as pedometers have focused on increasing daily activity but not on reducing inactivity.

Hypothesis:
Sedentary women will decrease inactivity if given a real time reminder of inactivity .

Method:
We developed a program to monitor real-time activity levels generated by a wearable activity monitor (Fitbit). Fitbit communicated step counts to a smartphone which sent this information to a database every 15 minutes. When 10 or fewer steps had been recorded for a 60 min period of time, an inactivity reminder text message was sent to the participant to encourage them to move about. 30 obese women with self-reported > 3 hours of inactivity per day, were enrolled, provided with a Fitbit and smartphone, and monitored for 8 weeks. Women were randomized to two groups. Gp A received inactivity reminders (IR) for the first 4 weeks followed by 4 weeks without IR. Gp B received no IR during the first 4 weeks and IR was given during the second 4 weeks. We defined inactivity as ≤ 20 steps in a 2 hr block. We compared the percent of 2-hr blocks between 8:00 and 24:00 hr where women were inactive during the 4 weeks with IR-on vs IR-off, for each of the 2 groups. The mean number of steps per day over each 4 week block was also compared.

Results:
Gps A and B were similar in age (51.8
+
12.2 y), BMI (37.1
+
6.9), self-reported hypertension (27% ), diabetes (23 %), and hyperlipidemia (23%). Fitbit data was available from 27 women. Gp A (n=15) self-reported 5.2
+
2.5 hr sitting/day at work during IR-off vs 3.9
+
2.7 with IR-on (p<0.004). Gp B (n=12), who had IR turned on in the second 4 week block, self-reported no change in hours sitting with or without IR. Activity monitoring data showed that Gp A were inactive for 32
+
23% of the 2-hr periods during the 4 weeks with IR-off vs 21
+
14% with IR-on (p < 0.004). However, Gp B had no difference in inactivity periods (28
+
12% with IR-off vs 28
+
14 % with IR-on). There were no differences in mean total daily steps walked during either 4 week block with IR-on or IR-off in either Gp.

Conclusion:
The use of real-time text messaging to inform women that they had been inactive for more than 60 mins was associated with a reduction in number of inactive periods independent of the number of steps taken a day. However, this effect was seen only when the reminder was implemented soon after enrollment. The behavior change did not persist after the reminders stopped. This study demonstrates that automated real time reminders can reduce periods of inactivity though the timing of the intervention affected the results. Further work will explore the behavioral factors that could improve the effectiveness and sustainability of the intervention.