The Effect on Attendance of an SMS Notification Prior to a Scheduled Screening Appointment in BreastScreen Norway

This study has been designed as a randomized controlled trial including women invited to a national screening program for breast cancer in Norway, BreastScreen Norway in 2025. The program invites women aged 50-69 to biennial screening mammography. The study includes two substudies with the intervention of sending an SMS notification three days prior to the screening appointment in the first substudy and two days prior to the screening appointment in second study. The comparison is made between the study groups, where women are sent an SMS notification two or three days prior to their scheduled screening appointment and the control groups where women will not be sent an SMS notification about a scheduled screening appointment.

NCT Number	NCT07355569
Lead Sponsor	Norwegian Institute of Public Health
Conditions	Attendance, Breast Cancer Screening
Enrollment	133,770 participants
Start Date	2025-01-10
Primary Completion	2025-10-31 (estimated)
Study Completion	2025-10-31 (estimated)
Updated on ClinicalTrials.gov	2026-01-23