Your Email Open Rate Is Lying to You

Every email platform in the world puts the open rate at the top of the dashboard. It's the biggest number, it's usually the healthiest-looking one, and for most practices it's the number they quote when someone asks how the email is going.

It stopped meaning anything in 2021.

We run patient email for 250+ chiropractic practices. Across those practices, over the last twelve months, the reported open rate sits around 37% — which by any industry benchmark is excellent. Healthcare email averages somewhere in the low twenties.

That 37% is not a measure of how many patients opened your email. It's mostly a measure of how many of your patients use Apple Mail.

What Apple did

In September 2021, Apple shipped Mail Privacy Protection. When a patient using Apple Mail receives your email, Apple's servers download the message content — including the invisible tracking pixel that email platforms use to register an "open" — whether or not the patient ever looks at it.

From your email platform's point of view, that's an open. Same signal, same dashboard entry, same green number going up.

Apple Mail accounts for roughly half of all email opens worldwide. In a patient population, it skews higher still — these are people on iPhones checking mail on the sofa, not marketers on desktop Outlook.

So a meaningful chunk of your 37% is Apple's servers, not your patients. The number went up after 2021 across the entire email industry, and nothing about anyone's email got better.

Here's what makes it worse than merely useless: it's uneven. You can't apply a correction factor, because the proportion of Apple users varies by practice, by patient demographic, and by which segment you happened to email that week. Two campaigns showing 35% and 42% might be identical in real performance. You cannot compare them, and you cannot compare yourself to anyone else.

So people moved to clicks

The standard advice, once open rates broke, was to measure clicks instead. Clicks are a real action. Nobody's server clicks a link by accident.

That advice is correct and it doesn't help much, because of how small the numbers are.

Across our practice base, the overall click rate on patient emails runs around 0.25%. On reactivation emails specifically — messages to patients who finished care and drifted off — it's between 0.01% and 0.1%.

Read that again, because the instinct is to assume it's a typo. Send a reactivation email to a thousand former patients and you might see one click. Sometimes none.

Now consider what that does to your decision-making. You want to know whether last month's email worked better than this month's. One had two clicks, the other had four. Is that a 100% improvement, or is it two people?

It's two people. At those volumes, every number you'd want to act on is inside the noise. You could A/B test subject lines for a year and learn nothing statistically real.

The finding that surprised us

We assumed reactivation emails would perform better with an offer attached. It's the obvious move — give a lapsed patient a reason to come back, make it easy, discount the re-exam.

The data doesn't support it. Across our base, reactivation emails carrying a discount offer correlate with worse engagement than ones that simply teach something useful and invite the patient to book.

We've thought about why. The most plausible explanation is that a discount changes what the email is. An email that explains why their shoulder still hurts eighteen months later is a useful thing to receive from a doctor. An email offering 40% off a re-exam is an advertisement, and people have well-developed reflexes for advertisements.

There's a second-order problem too. Discount reactivation trains a database to wait. If every few months brings another offer, the rational move for a patient who might come back is to keep not coming back until the next one arrives.

We were wrong about this one, and it's worth saying so plainly, because a great deal of reactivation advice in this profession — including advice we've given — starts from the assumption that the offer is the lever.

What to measure instead

If opens are contaminated and clicks are too small to read, what's left?

Named patients who booked.

Not a rate. Not a percentage. A list of people, with names and phone numbers, who did something that indicates they're thinking about coming back.

This is a better metric than either of the others for a reason that has nothing to do with statistics: you can act on it. A 0.3% click rate is information you can't do anything with. "Sarah Whitfield, who finished care in March, just tapped the call button on the email about stress and back pain" is not a metric at all. It's a phone call your front desk should make in the next ten minutes.

The shift is from measuring the email to measuring the patient. Once you make it, most of the questions that seemed important stop mattering. You stop asking whether the open rate improved. You start asking how many patients your email surfaced last month, and how many of them your team actually called.

That second number is usually the one that needs work.

What this means for your practice

Three things follow.

Stop reporting open rates internally. If your marketing person or agency reports open rate as evidence the email is working, they're either not aware of Apple's change or they're relying on you not being. Neither is good. Ask what the email produced instead.

Stop optimizing at low volume. If a campaign produces single-digit clicks, you cannot learn anything from comparing it to another campaign that produced single-digit clicks. Effort spent on subject-line testing at that scale is effort not spent on the thing that actually moves reactivation, which is sending consistently for long enough that patients' own timing catches up with you.

Build the path from signal to phone call. Whatever you use, the important question is what happens between a patient clicking and someone calling them. In most practices the honest answer is "nothing" — the click lands in a dashboard nobody opens, and the patient who was thinking about booking goes back to not booking. That gap is where the actual loss is, and it has nothing to do with which metric you chose.

A note on where these numbers come from

Everything here comes from twelve months of send, open, and click data across the practices we run email for 250+ practices and roughly 350,000+ actively engaged patients. It's a large enough base to be confident about direction, and it's specific to chiropractic patient populations, which behave differently from retail or B2B lists.

We'll keep publishing what we find, including the parts that don't flatter us. The discount finding was one of those. There will be more.

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Patient Pilot surfaces every patient who clicks — by name, with their contact details and stage of care — and texts your team so they can follow up while the patient is still thinking about it. See how it works →