Using Nudges to Reduce Missed Appointments in Primary Care and Mental Health: a Pragmatic Trial.

Background: Missed appointments ("no-shows") are a persistent and costly problem in healthcare. Appointment reminders are widely used but usually do not include messages specifically designed to nudge patients to attend appointments.

Objective: To determine the effect of incorporating nudges into appointment reminder letters on measures of appointment attendance.

Design: Cluster randomized controlled pragmatic trial.

Patients: There were 27,540 patients with 49,598 primary care appointments, and 9420 patients with 38,945 mental health appointments, between October 15, 2020, and October 14, 2021, at one VA medical center and its satellite clinics that were eligible for analysis.

Interventions: Primary care (n = 231) and mental health (n = 215) providers were randomized to one of five study arms (four nudge arms and usual care as a control) using equal allocation. The nudge arms included varying combinations of brief messages developed with veteran input and based on concepts in behavioral science, including social norms, specific behavioral instructions, and consequences of missing appointments.

Main Measures: Primary and secondary outcomes were missed appointments and canceled appointments, respectively.

Statistical Analysis: Results are based on logistic regression models adjusting for demographic and clinical characteristics, and clustering for clinics and patients.

Key Results: Missed appointment rates in study arms ranged from 10.5 to 12.1% in primary care clinics and 18.0 to 21.9% in mental health clinics. There was no effect of nudges on missed appointment rate in primary care (OR = 1.14, 95%CI = 0.96-1.36, p = 0.15) or mental health (OR = 1.20, 95%CI = 0.90-1.60, p = 0.21) clinics, when comparing the nudge arms to the control arm. When comparing individual nudge arms, no differences in missed appointment rates nor cancellation rates were observed.

Conclusions: Appointment reminder letters incorporating brief behavioral nudges were ineffective in improving appointment attendance in VA primary care or mental health clinics. More complex or intensive interventions may be necessary to significantly reduce missed appointments below their current rates.

Trial Number: ClinicalTrials.gov, Trial number NCT03850431.