In outpatient surgery, the patients may be called by phone for detecting and managing perioperative problems. However, phone calls consume time and can waste caregiver’s time when the patient is not available. Information and communication technologies could bridge the gap between available resources and need to contact patients.

In the present before-after study, the before-implementation group was contacted by phone (phone group). The after group was contacted with a SMS or a phone call according to patient’s preference (SMS group). The primary outcome was the non-inferiority of the SMS system on the occurrence of preoperative events disturbing the organisation of unit including cancellation of the case related to patient’s condition the day before and the day of surgery; non-compliance with fasting rules or requirement of an escort; non-adherence to instructions regarding medication; not reporting to the surgical centre, or a delayed arrival > 30 min.

Among 1300 included outpatients (650 per group), 381 (59%) and 542 (83%) patients were successfully contacted in the preoperative period in phone or SMS group, respectively P < 0.0001). Preoperative events were observed in 94 patients of the phone group (14.5% [CI 95% 11.9–17.3]) and in 77 patients of the SMS group (11.8% [CI 95% 9.5–14.6]), meaning that the upper bound 95% CI of the group was within the non-inferiority margin.

In outpatient surgery, implementation of an SMS-based system, supplemented by phone calls for contacting patients is not inferior to a phone-based system in regard to preoperative events.