Designing Personalized SMS Reminders to Reduce Outpatient No-Shows: A Cross-Sectional Study Under Taiwan’s Universal Health System (Preprint)

BACKGROUND Missed outpatient appointments (“no-shows”) undermine care continuity and healthcare system efficiency. While short message service (SMS) reminders are widely adopted to reduce no-shows, the design of message content, especially personalization based on patient characteristics, remains insufficiently explored. OBJECTIVE This study aimed to identify patient preferences for different types of SMS reminder content and to examine the sociodemographic and behavioral factors associated with these preferences under Taiwan’s universal healthcare system. METHODS A cross-sectional online survey was conducted among 1,095 adults in Taiwan with outpatient experience. Participants evaluated six behaviorally-informed SMS reminder prototypes. Preferences were analyzed using descriptive statistics and chi-square tests, and associations with demographic and healthcare utilization variables were examined. RESULTS Among respondents, 47.5% preferred reminders referencing prior missed appointments, followed by general reminders (31.1%). Fewer participants favored emotionally framed or relational message types. SMS content preferences varied significantly by gender, age, education level, occupation, residence, and prior no-show history (p < .05). Women, younger adults, and individuals with past missed appointments were more likely to prefer neutral or behavior-linked reminders, while older adults and highly educated professionals showed greater preference for empathetic content. CONCLUSIONS Preferences for SMS reminder content are significantly shaped by patient demographics and healthcare behaviors. Tailoring reminder messages based on user profiles may enhance salience, improve appointment adherence, and reduce no-shows. These findings inform the development of user-centered communication strategies in digital health and support future implementation in large-scale trials. CLINICALTRIAL The study was approved by the Institutional Review Board of Kaohsiung Medical University Hospital (IRB No. KMUHIRB-E(I)-20240047).