Effectiveness of an mHealth intervention to increase participation in breast cancer screening (Breast Cancer ATICA Study): a pragmatic randomized controlled trial.

Implementation of invitation systems has been shown to increase breast cancer (BC) screening rates. However, implementation of active outreach strategies in Latin American programs is limited. We conducted a pragmatic randomized controlled trial -the BC ATICA Study- to evaluate the effectiveness and implementation of a digital messaging-based intervention to increase BC screening. A total of 248 Argentinian women aged 50 + years were recruited from ten health care centers in Santa Fe, Argentina, and randomly assigned (1:1) to the intervention (n=123) or control group (n=125). The intervention included up to four SMS messages inviting participants to schedule an appointment for mammography through WhatsApp or the usual care control group (n=125). Effectiveness outcomes were the proportion of women who underwent mammography within 105 or 45 days of enrollment. The RE-AIM framework was used to evaluate the implementation of the intervention. Our results showed that women in the intervention group (n=123) were significantly more likely than women in the control group (n=125) to undergo a mammography within 105 days (23.6% vs. 6.4%, difference 17%, 95%CI: 7.7% to 27.0%) and within 45 days (15.4% vs. 3.2%; difference 12%, 95%CI:4.3% to 20.0%, p=0.02). Our results also showed high acceptability and appropriateness of the intervention. Our study demonstrates that sending consecutive SMS messages, including a WhatsApp number to ask for an appointment, effectively increased BC screening. This mHealth intervention could be an excellent option to improve access to breast cancer screening in low- and middle-resource settings where active invitation systems are challenging to implement.