FOLIO 09 / 01 · Reminders
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SMS / Email / Phone · Evidence base

SMS vs email appointment reminders.

A 2011 systematic review of 29 studies found reminders cut no-shows by a weighted mean of 34% of baseline: automated and SMS reminders by about 29%, manual phone calls by about 39%. Email alone is weaker, around 15 to 20%. Here is the full evidence.

Evidence base

Key studies

StudyNSettingReduction
Hasvold & Wootton 2011 (primary)29 studiesHospital outpatient (mixed)29% SMS / automated, 39% phone
Cochrane review (Gurol-Urganci 2013)4 RCTs (3,547)Healthcare (mixed)RR 1.10 attendance
Citation archive with DOI links →
Timing

Optimal timing

48 hours before
Full reminder with all details
22% reduction alone
2 hours before
Brief confirmation prompt
+12 to 16% additional
No reply by T-4hr
Staff callback + waitlist notify
Mitigates remaining gap
Channel

SMS vs email vs phone

SMS (two-way confirmation)
Highest effectiveness, fastest
28 to 38%
SMS (one-way)
Good baseline
20 to 25%
Email
Additive to SMS, not replacement
15 to 20%
Phone call
Most effective per contact, not scalable
35 to 45%
Patient portal message
Additive for established patients
10 to 15%
TCPA compliance

US healthcare SMS rules

The Telephone Consumer Protection Act (TCPA) requires written consent before sending automated SMS messages to US mobile numbers. For healthcare appointment reminders:

  • ·Obtain express written consent at patient intake (paper or digital form)
  • ·HIPAA-covered entities: appointment reminders are “treatment, payment, operations” communications. Consent is implicit if the patient provided their number.
  • ·Always provide an opt-out mechanism (reply STOP)
  • ·Restaurant and salon reminders require explicit opt-in as they are commercial messages
  • ·Most reminder platforms (Weave, SolutionReach, Fresha) handle TCPA compliance automatically
Reduce hubOverbooking mathPolicy templatesReminder platformsResearch

Margin notes

Do SMS reminders work for reducing no-shows?+
Yes. Hasvold and Wootton's 2011 systematic review of 29 studies found reminders cut no-shows by a weighted mean of 34% of baseline: automated and SMS reminders by about 29%, manual phone calls by about 39%. Reminders are the strongest evidence base of any single intervention. Two-way confirmation (requiring patient reply) adds approximately 15% effectiveness, lifting a two-stage SMS program toward the upper end of that range.
How many reminders should I send?+
The evidence supports two reminders: one 48 hours before the appointment and one 2 hours before. Three or more do not significantly improve outcomes over two and increase opt-out rates. The 48-hour reminder should include full appointment details. The 2-hour reminder should be brief and action-focused.
Is SMS or email better for appointment reminders?+
SMS significantly outperforms email for no-show reduction. SMS open rates are 98% versus 20-30% for email. Hasvold and Wootton 2011 found automated and SMS reminders cut no-shows by about 29% of baseline (manual phone calls about 39%), versus roughly 15-20% for email alone. However, email adds an additional 8-12% reduction when combined with SMS, making both together optimal.

Register entries verified 2026-04-28