Our data
At the typical clinic, more than 1 in 4 patient messages arrive outside business hours
At the median clinic, 27.0% of the WhatsApp messages patients sent arrived outside Monday to Friday, 8 am to 6 pm. We counted 24,460 messages sent to 19 clinics in Brazil that use Certu, between July 30 and October 14, 2026. Pooled together it is 23.6% (5,775 messages), lower because one large clinic, whose patients write mostly during business hours, sent more than half of all messages. At a typical clinic, more than one message in four lands when the front desk is closed.
When patients write
- The busiest hour is 11 am, and Wednesday is the busiest day (23.3% of messages).
- 25.4% of conversations start outside business hours, so the first thing many patients get is either an answer or silence.
- A typical conversation has 6 messages (median). Voice notes are 3.9% and photos 3.7% of what patients send.
It varies a lot from clinic to clinic
One clinic sent 55.8% of all the messages in the sample, so we also checked the numbers without it. Without the largest clinic, 30.9% of messages arrived outside business hours. Looking clinic by clinic (the 12 clinics with at least 200 messages), the median clinic received 27.0% of its messages outside business hours, and the range went from 6.7% to 63.8%. The only way to know your own number is to count your own messages.
How fast the AI replied at these clinics
| Share of replies | Every AI reply | First reply in a conversation |
|---|---|---|
| 50% (median) | 11.6 s | 15.8 s |
| 75% | 16.9 s | |
| 90% | 20.4 s | 25.1 s |
| 99% | 28.2 s |
What this means for a clinic
A patient who writes at 9 pm usually isn't browsing. They want something settled: can I come in, how much is it, do you take my insurance. If nobody answers until the next morning, some of them write to the next clinic on the list. Answering after hours does not require booking anything: it only takes a reply, the request collected, and the details waiting for your team in the morning.
Across all industries
For comparison, across 88,892 WhatsApp messages sent to 61 businesses of every kind on our platform (July 30 to September 21, 2026), 32.7% arrived outside business hours. Over 7 days ending August 25, 2026, our AI's median reply time across all accounts was 15.4 s, with 9 in 10 replies within 24.8 s (1,058 replies).
How we measure
- Clinics in the sample: accounts registered as clinics, or with a human-health name. Veterinary and pet businesses, test accounts and our own accounts are excluded. 67 clinic accounts qualified; 19 had patient messages in the period.
- Messages: WhatsApp only. Chat history imported from before a clinic joined is excluded.
- Business hours: Monday to Friday, 8 am to 6 pm.
- Where: all 19 clinics are in Brazil. Patterns elsewhere may differ.
- Privacy: we only publish totals. No message content is published, and no clinic or patient can be identified.
- What we can't measure yet: no-shows and completed bookings, because most clinics book in their own scheduling system, outside our platform. We won't publish those numbers until we can measure them properly.
What patients say in Google reviews
We also read the negative Google reviews of 400 clinics in Brazil. 25.3% of them were about not being able to reach the clinic by phone or WhatsApp, and the clinics replied to 4 of those 75. See the review study.
What we'll publish next
We re-run this measurement every month and update the numbers here, with the date and the sample next to each one. As more clinics join, the sample grows and the ranges get tighter.
Answer the patients who write after hours
Try ClinicConvo free: up to 200 patient messages within 7 days, no card.
Try it freeKeep reading
- AI Front Desk for Clinics: What It Handles, What Staff Do
- AI Receptionist for Medical Offices: 2026 Buyer's Guide
- AI Scheduling Assistant for Clinics: Can AI Book?
- AiSensy Alternatives for Clinics (2026)
- Appointment Reminder Texts: What Cuts No-Shows
- DenGro Alternatives for UK Practices (2026)
- HIPAA Compliant Chatbot: What It Takes and How to Check
- AI Medical Answering Service: Cost, Limits, AI vs Live
- Medical Chatbot for Clinics: Rule-Based vs AI
- Pabau Engage Alternatives for UK Clinics (2026)
- Respond.io Alternatives for Clinics (2026)
- Wati Alternatives for Clinics (2026)
- WhatsApp Business API Pricing and HIPAA for Clinics
- WhatsApp Chatbots for Clinics: 9 Tools Compared (2026)
- 1 in 4 bad Google reviews of clinics are about not being able to reach them