CMS covers more ambulatory blood pressure measurements now. Wait! Before you fall asleep–this is a bigger deal than you think.

Of all medical interventions available to physicians taking care of adults, blood pressure control may have the largest potential impact on lives saved. Since more than a third of Americans have hypertension, every 10 percent increase in controlled blood pressures nationwide would save something like 14,000 lives per year. And right now, less than half of people with hypertension have a well-controlled blood pressure. Going from 50% control to 90% control could be expected to save almost 60,000 lives per year. Part of the problem with getting there, though, is that measuring a blood pressure accurately is astonishingly hard. Some of this is due to obvious errors by the measurer: using the wrong size cuff, taking the measurement over clothes, and talking to you while they inflate the cuff, for example.

But some of the error is less predictable. A clever recent study (paywall) found that when participants in the SPRINT study, a large trial of very intensive blood pressure control, were seen by their own doctors during the study but outside the study protocol, their blood pressures differed markedly from the blood pressures obtained by the fastidious measurement techniques of the protocol. People in the “intensive” control group, in whom investigators were aiming for a blood pressure <120 mmHg, had a routine blood pressure at their own doctors’ offices that was 7.3 mmHg higher. People in the standard control group who were aiming for a blood pressure <140 mmHg had an average difference of 4.6 mmHg between their study blood pressure and their routine blood pressure.

Unfortunately, your own doctor may not be able to put in the time or workflow that it takes to get a study-quality blood pressure. She may not be able to let you rest for 5 minutes before a reading, or she may not invest in automated blood pressure cuffs. She may not have the time to average the results of three separate readings. But what your doctor could do is prescribe “ambulatory blood pressure monitoring,” or ABPM. ABPM is a technique by which you wear a device at home that periodically monitors your blood pressure, even at night, without any input from you. Then it sends the results to your doctor. Because the device is unaffected by the technique and timing issues above, it is considered the gold standard for the diagnosis of hypertension. But it has been historically very hard to get insurance companies to pay for. Getting payment required documenting a high likelihood of “white coat hypertension,” that is, a blood pressure in the doctor’s office that was consistently higher than blood pressures obtained outside the office on more than one occasion. People with “masked hypertension,” whose blood pressures outside the office may have been substantially higher than those measured at the doctor, were excluded.

A recent rule change by Centers for Medicare and Medicaid Services (CMS), though, allows expanded use of ABPM not only for suspected white coat hypertension, but also for masked hypertension. Since CMS is the bellwether for other insurers’ behavior, we can surely expect private insurers to follow.

So check your blood pressures at home. Or go to your local fire station or EMS. They can check your blood pressure 24/7/365 for free, and they know what they’re doing. See the image below to locate all the EMS and Fired Department stations in Sedgwick County, or download your own copy here. There is also an area where you can track your out-of-clinic blood pressures to report back to your physician.

If your home readings don’t match what you’re getting from your doctor’s office, ask your doctor about doing ambulatory blood pressure monitoring. Better yet, encourage your employees to ask about it.

Note: the Kansas Business Group on Health receives CDC funding to improve the detection and care of high blood pressures. But we believe in it either way.

As the Medical Director of the Kansas Business Group on Health I’m sometimes asked to weigh in on hot topics that might affect employers or employees. This is a reprint of a blog post from KBGH.