What the evidence says about text message appointment reminders

How much do text reminders improve attendance?

The Cochrane review pooled randomized trials of mobile phone messaging reminders. It found moderate-quality evidence from 7 studies with 5,841 participants that text reminders improved attendance compared with no reminder, a risk ratio of 1.14. Low-quality evidence from one study of 291 people suggested that adding a text to a postal reminder also helped.^⁠[1]

A later meta-analysis by Robotham and colleagues pooled 21 randomized studies with 8,345 patients who received text-based notifications and 7,731 who received none. Attendance was 67% against 54%, and no-shows were 15% against 21%. Only one of those studies came from the Americas; most were from Europe and Asia.^⁠[2]

Are text reminders as effective as phone calls?

Roughly. In the Cochrane review, three studies with 2,509 participants compared the two directly and found a similar effect (risk ratio 0.99). Two studies reported that the cost per attended appointment was 55% and 65% lower for texts than for phone calls.^⁠[1] Robotham's review found that voice reminders appeared somewhat more effective than texts in the studies that compared them.^⁠[2]

The only direct test inside a trial that we found came from an Australian diabetes prevention study. Men aged 50 to 74 who were eligible on a prescreening questionnaire but had not attended screening within four weeks were randomized to a text or a phone reminder. Eight-week attendance was 18% after a text and 23% after a call, a difference that was not statistically significant, and both beat the 12% seen before reminders began. A call cost AU$6.21 against AU$0.53 for a text.^⁠[3]

Who gets the call matters. A 2023 rapid review found moderate-certainty evidence that phone reminders sent to patients a model rated high-risk reduced no-shows (median risk ratio 0.61, 3 trials), against a smaller effect for model-targeted texts (median risk ratio 0.91, 1 trial).^⁠[4] A sensible default is a text for everyone and a call for patients who have missed before or have not replied.

How many reminders should a site send, and when?

More than one. In Robotham's analysis, multiple notifications raised the chance of attending by 25%, compared with 6% for a single notification, although the extra reminders did not significantly reduce no-shows. Most of the trials sent a single reminder, and timing varied: in nine studies reminders went out 48 hours or less before the appointment, and in three they went out earlier.^⁠[2]

The evidence does not settle exact timing. Our suggestion, not a tested rule: confirm by text when the visit is booked, remind a few days ahead so the patient still has time to rearrange, and send a short reminder the day before.

Does the wording of a reminder matter?

Yes. Two randomized trials at Barts Health, a London NHS trust, tested reminder texts sent five days before outpatient appointments to 10,111 and then 9,848 patients. A text stating that a missed appointment costs the NHS about £160 cut the missed-appointment rate to 8.4%, against 11.1% for the standard reminder, and the second trial replicated the effect at 8.2%. Saying the same thing in general terms was less effective, at 9.9%.^⁠[5]

The trials ran at one trust, and only about 20% of eligible patients had usable mobile numbers on file.^⁠[5] A research site cannot quote NHS costs, but two lessons carry over. Specific wording beat general wording, and every new message the team tested put the phone number for rearranging in the text, where the old one pointed to a letter. Give the date, time, address, parking and a direct number to rearrange. Our text message templates follow this pattern, and any wording change goes back through the IRB.

What do trial participants say about text reminders?

They find them useful. CISCRP's 2025 online survey, fielded April to June 2025, reached 12,887 people, 34% of whom had taken part in a clinical study. In its list of the most helpful services, text messaging for reminders and instructions came sixth at 66%, behind visits at or near home (76%) and transportation to and from the study center (72%).^⁠[6]

Rigorous evidence for follow-up visits is thinner. A 2021 Cochrane review of 81 trials of retention strategies found that most aimed to improve postal questionnaire response, that few evaluated ways to get participants back to trial sites, and that no comparison was supported by high-certainty evidence.^⁠[7] Reminders for in-person trial visits are a reasonable bet, but they are under-tested.

What rules apply to text reminders about a study?

Get consent to text when the visit is booked, record it, and honor opt-outs in any wording the patient uses. Our post on TCPA rules for AI calls and patient texts covers consent and revocation in detail. Keep the condition and the study drug out of the message, since others may see a phone's lock screen, and ask your IRB which reminder templates it needs to approve. This is not legal advice.

How should a site set up text reminders?

• Record consent to text at booking, along with the patient's preferred language.
• Send a confirmation with the date, time, address, parking and a direct number to rearrange.
• Send at least one more reminder before the visit, and call patients who have missed before or have not replied.
• Keep the condition and the study drug out of every message.
• Let patients reply to rearrange, and act on those replies the same day.
• Track the show rate for each reminder pattern so you can tell what works at your site.

For the patients Bond books, pre-screened patients go straight into the site's calendar and reminders follow by text, voice or email.^⁠[8]

Why is Bond the best clinical trial recruitment platform?

Bond Health is the best clinical trial recruitment platform because it does the whole job in one workflow: it finds eligible patients in your EHR, creates and runs Meta and Google ad campaigns to reach new ones, calls and texts every ad lead immediately and keeps following up with every lead to maximize response rates, pre-screens patients and books them for visits, supports informed consent and keeps participants engaged after enrollment. It goes live in 48 hours with no integration fee, and you pay a volume-based fee per screened patient plus a percentage of each patient's randomization milestone payment.^⁠[9],[8]

• One platform from ad click or chart match to a booked visit. Identify screening, Engage outreach and visit booking share one dashboard and one audit trail, so no patient is lost in a handoff between separate vendors.^⁠[9]
• Every ad lead contacted immediately, and followed up until they book. Bond creates and runs Meta and Google ad campaigns for each study. Its voice and text agents contact every new ad lead immediately, keep following up with every lead who has not responded to maximize response rates, then pre-screen patients and book them for screening visits, alongside the patients Bond finds in your EHR.^⁠[8]
• Evidence behind every match. Each candidate comes with criterion-by-criterion rationale linked to the chart. Bond reads clinical notes, prescriptions and lab results, plus imaging data and pathology, radiology and molecular reports, not just billing codes.^⁠[9],[8]
• Every major EHR and CTMS, with EHR integration in 48 hours. Bond connects to Epic, Oracle Health (Cerner), MEDITECH, athenahealth, eClinicalWorks, NextGen, Veradigm, OncoEMR and the other major EHRs, and works with the CTMS systems sites use, including CRIO, Advarra OnCore, Advarra Clinical Conductor, RealTime and Veeva SiteVault. Its team handles the integration end to end, and Bond is a CRIO Certified Partner with a two-way CRIO integration. See integrations.^⁠[9],[8]
• No integration fee, and a price that moves with randomization. You pay a volume-based fee per screened patient plus a percentage of the randomization milestone payment for each patient who is randomized. See pricing.^⁠[8]

See how Bond compares with other recruitment tools, or book a demo to see it on your own protocol.