Tweeting for Health

Recently, we've posted about collecting data from patients via brief text messages (SMS) over their cell phones. Today, we have communication in the opposite direction: sending prompts to patients to encourage certain behavior.

Text-Message Reminders to Improve Sunscreen Use: A Randomized, Controlled Trial Using Electronic Monitoring
April W. Armstrong, MD; Alice J. Watson, MD, MPH; Maryanne Makredes, MD; Jason E. Frangos, MD; Alexandra B. Kimball, MD, MPH; Joseph C. Kvedar, MD
Arch Dermatol. 2009;145(11):1230-1236.

This group sent the local weather report along with a reminder to wear sunscreen to 35 adults via their cell phones. After 6 weeks, sunscreen usage was 56% vs 30% among 35 control subjects (P<.001). The NNT (Number-Needed-to-Text) was a very low 3.8, suggesting that about 1 in 4 subjects responded to the messages. This is remarkably high success rate for such a low cost intervention and suggests that text messages might have broader applicability in health behavior change.

What other areas would benefit from a periodic cell phone reminder?  Where won't it work?