At-home testing for heart failure, transplant patients: Can it work?

The key difference between this study and the heart failure study, Dr. Nerenz pointed out, is that the transplant recipients didn’t have automatic data upload. “Patients were responsible for doing the testing and then manually entering the information into a study database. And so the question here is, Is this feasible?” The finding: “Patients were much better at performing the measurements than they were at registering” the results, said Dr. Nerenz.

The study also addressed whether the data are sufficiently accurate to make clinical decisions. The authors examined this by comparing the accuracy of results using the POC method from a fingerstick with a concurrently collected venipuncture specimen tested in the central lab. Using a total allowable error of 6.9 percent, they found that many points fell outside the allowable error.

“So you could say, well, that’s it. It’s not sufficiently accurate. This is not going to work. But the authors point out that, similar to the BNP study, we know the individual data points are not going to be as accurate. We’re not contesting that point,” he said. “What we want to know is, What’s the trend? Is creatinine going up or down?”

The authors found disagreement on each day of testing, “but the trends are the exact same. When it goes up on one method, it goes up on the other, and vice versa,” Dr. Nerenz said.

How well did patients follow the feedback provided to them through the online system? Of 258 requests the system provided to patients to perform a repeat measurement, only 53 percent of those were followed. Of the second measurements that were performed, 39 got an orange light and a request to perform another measurement the next day, and 85 percent of those requests were adhered to. Finally, of 24 requests to contact the hospital, only 58 percent were adhered to.

“So the authors quite rightly were concerned by this and they thought, ‘Why aren’t these patients doing what the system is telling them to do?’ And what they realized is that these non-adherence episodes were due to delayed registration,” Dr. Nerenz explained. “If a patient got a creatinine value on Monday that would say, ‘do another measurement’ or ‘go to the hospital,’ but they didn’t log that in the system until Friday, they’re going to say, ‘That’s old news. I don’t have to act on that.’ So it kind of gets back to manual entry versus automatic data entry.”

To assess how accurately the patients entered data, the authors compared 3,963 measurements logged into the device to values registered online on the same day and found that 3,448 (87 percent) were registered correctly, while 515 (13 percent) were incorrect.

“But what I find most interesting is there were about 1,300 unregistered measurements”—measured values that were never entered into the online system. Six hundred ninety-one (54 percent) were omitted, and 600 (46 percent) were unselected. In the latter case, “these are values where a patient was instructed to do one measurement and did two or three or four and had multiple different values to pick from but selected one of those values for upload and then the others were not uploaded.”

When the authors compared the mean values of selected and unselected measurements, they found the omitted values were significantly higher than the registered ones, suggesting patients tended to make their kidneys “look best,” Dr. Nerenz said, adding, “I think automatic data upload is a necessity.”

As with the BNP study, he said further research is needed to define the optimal alert criteria and to determine whether at-home creatinine testing improves patient outcomes. “There are some ways that this [at-home testing] can go wrong . . . but, by and large, I think this has definite potential.”

To be implemented successfully, he said, these devices should require minimal training, testing has to be convenient for the patient, and results have to be accurate. “But we know there are going to be inaccuracies if we compare single data points generated at home versus single data points generated on a venipuncture specimen in the lab. But I would argue that’s okay because we’re gaining real-time information that we can use to trend patients, as opposed to gaps in information because we’re only testing once a week or once a month or every six months, or whatever it may be.”

Automatic data reporting is a must, he repeated. “Manual entry is not a viable solution.” And the data have to be actionable: “There has to be something we can do to intervene. If there’s no treatment we can offer the patients, there’s no point in doing any of this.”

Brenda Suh-Lailam, PhD, DABCC, director of clinical chemistry and point-of-care testing and director of quality, Department of Pathology, Ann and Robert H. Lurie Children’s Hospital of Chicago, and assistant professor of pathology, Northwestern University Feinberg School of Medicine, said in the same AACC session and in a recent interview that the use of at-home testing devices on inpatients, when they’re brought into the hospital, is one of the POC testing challenges laboratories will face in the future. There are no guidelines, for example, on how to manage results from inpatients with continuous glucose monitors.

“Should the results be downloaded into the patient’s electronic medical record while they are an inpatient?” she asks, adding that policies for such are needed. “Do laboratorians need to validate or calibrate at-home devices? Will they need to ensure quality throughout inpatient CGM use?” And “what is the laboratory’s responsibility for training and troubleshooting related to at-home device use?”

A panel of 27 experts in hospital medicine and endocrinology in 2015 discussed the current and potential future roles of CGM in the hospital (Wallia A, et al. J Diabetes Sci Technol. 2016;10[5]:1174–1181). They concluded, Dr. Suh-Lailam says, that it has the potential to provide useful information and improve care in ICU and non-ICU settings and that there is a role for continuing the use of home CGM in the hospital, but that the cost and lack of outcome data limit widespread adoption. Whether there is a role for laboratorians in this setting is still an open question, Dr. Suh-Lailam says.

To illustrate the challenges related to at-home device use—in this case a ketone meter—in a hospital, Dr. Suh-Lailam shared a case in which a patient with glycogen storage disease type IIIa was scheduled for a four-day inpatient diet treatment to begin in eight days at her institution. Ketone and glucose checks were needed every one to two hours to monitor treatment efficacy.

“The problem was that we were not yet offering ketone testing in our laboratory, so the clinical team was wondering if they could use the patient’s ketone meter since testing was required so often,” she said. “However, the problem with using the patient’s meter is that its performance has not been validated for use in our hospital, so clinical decisions cannot be made using that device. We had to come up with a quick way to provide ketone results during this patient’s hospital stay.”

Purchasing and validating a POC testing device on short notice is a challenge, she says, as is training personnel on different shifts. “We decided to take on the challenge and we were fortunate to have vendors that were willing to work quickly with us to provide us with a hospital-grade point-of-care testing device, which we validated.”

“Personnel were trained and some then received additional training to be able to help train operators on other shifts. The success of this project was due to the collaboration between the lab, clinical team, and vendor,” she says.

A poll of attendees in the AACC session found that more than 80 percent said more POC testing is being done in their institutions compared with five years ago. Many said their institutions were acquiring, or recently acquired, a new POC testing device not used previously in their institutions. More POC testing to manage different disease states and more testing in nontraditional settings is what the future of POC testing will look like, Dr. Suh-Lailam says. And that includes more such testing in assisted-living and nonmedical facilities and, yes, the home.

“We seem to see more and more of the same kind of pattern,” Dr. Nerenz said, “where point-of-care testing continues to expand into areas beyond the traditional health care settings—outside the hospital, outside outpatient clinics.” If at-home patient self-testing “explodes,” he asks, “how can we insert ourselves into the discussion to make sure it’s done appropriately, correctly, and safely?”

David Wild is a writer in Toronto.