Healthcare Resource Utilization in Patients With Type 1 Diabetes With or Without Prior Type 2 Diabetes Misdiagnosis in a U.S. Managed Care Population | Written Recap

In this Managed Healthcare Executive Between the Lines video series, Diana Brixner, Ph.D., B.Pharm., and Shira Eytan, M.D., discussed Brixner’s research into Type 1 and Type 2 diabetes diagnoses, testing for Type 1 diabetes, and creating more awareness of Type 1. Brixner is a professor emeritus in the Department of Pharmacotherapy at the University of Utah in Salt Lake City and the founder of its Pharmacotherapy Outcomes Research Center. Eytan is an endocrinologist at Park Avenue Endocrinology and an adjunct assistant professor at New York University Langone Health, both in New York.

Diagnosis of Type 1 diabetes

Eytan said that Type 1 diabetes is diagnosed when laboratory tests show the presence of two of five autoantibodies that are signs of the disease. If someone has a hemoglobin (Hb)A1c of above 6.5% or a fasting glucose level of
126 mg/dL, they’re clinically diabetic and usually require insulin, Eytan said. Some of the complications of making the diagnosis are that some people have what Eytan called a “honeymoon phase” when they are not really hyperglycemic or have a brief period of hyperglycemia, and then their glucose drops to a normal level. “Some clinicians may be confused by that,” she said.

Eytan said there is also a misconception that Type 1 diabetes is a diagnosis made in childhood, “which is simply not true because adults can be diagnosed.” In fact, she said, the majority of Type 1 diabetes is diagnosed in adulthood. Many adults get misdiagnosed with Type 2 diabetes based purely on age. Checking antibodies helps differentiate between Type 1 and Type 2. Brixner said her “payer colleagues” have concerns about misdiagnosing Type 2 as Type 1 diabetes, the timing of testing, and the consequences of inappropriate management, including the improper prescribing of oral antibiotics and complications from hyperglycemia and diabetic ketoacidosis (DKA).

“We see it regularly as endocrinologists that patients went through years of trying all the different oral hyperglycemic agents, and none of them work and their HbA1c is still uncontrolled until they reach the correct diagnosis. And so, those are many years of wasted control and complications that the patient may suffer,” Eytan said.

Study results

Brixner gave a brief review of the design of her study, which compared healthcare resource utilization in individuals diagnosed with Type 1 diabetes with those who had incorrectly received a Type 2 diagnosis before being diagnosed with Type 1 diabetes. She and her colleagues conducted the retrospective study using an integrated claims database. They compared inpatient admissions, emergency room visits, outpatient visits, lab procedures, and prescriptions in the two groups. Brixner noted that the average age of those who originally received a Type 1 diagnosis was 27, compared with an average age of 45 among those who received a Type 2 diagnosis before a Type 1 diagnosis. The patients who first received a Type 2 diagnosis had more comorbidities than those who did not receive the incorrect diagnosis, Brixner noted.

Brixner and her colleagues found that 31% of those diagnosed with Type 1 diabetes had previously been diagnosed with Type 2 diabetes. “It really does show that it’s a bigger problem than certainly I had expected before we got some of the results from the study,” she said.

Brixner then reviewed the differences in healthcare resource utilization. Compared with those who had a prior Type 2 diabetes diagnosis, those without a misdiagnosis were less likely to experience inpatient admissions (11% vs. 3%, respectively), have an emergency room visit (24% vs. 11%), have outpatient visits (99% vs. 81%), and have laboratory procedures (88% vs. 53%). She noted that the results had “good solid confidence intervals,” and that the payers will consider the economics of the utilization differences.

“Because those who have the wrong diagnosis, you would expect them to be more hyperglycemic, uncontrolled, and therefore requiring more visits to their doctor, more adjustments of their medications, and, unfortunately, probably more [emergency room] visits for hyperglycemia or DKA,” said Eytan. “It doesn’t surprise me at all to see such a discrepancy between the two cohorts.”

Brixner noted some of the limitations of the study. As with most studies based on claims, there are issues with the underlying data being inaccurate or incomplete. She also noted that the lab data doesn’t include the results. However, as an experienced researcher, Brixner said the size of the study gives her confidence in the results.

When to test

Brixner said it isn’t feasible to test everyone for Type 1 diabetes who presents with an elevated HbA1c. Eytan said more guidelines are beginning to address screening for Type 1 diabetes and that population screening is being considered or done in some countries. In clinical practice, she said a practitioner can consider testing patients with other autoimmune conditions — she mentioned Hashimoto’s disease and celiac disease as examples — or a family member who does. In her practice, if a person with an autoimmune disease has signs of dysglycemia, she says she will test them for Type 1 diabetes. And, of course, she said, patients with family members with Type 1 diabetes should be prioritized for screening.

Classically, clinicians wouldn’t order antibody tests for Type 1 diabetes until after the patient already had a diagnosis of diabetes, Eytan said. “But now that there have been advances in the treatments that are offered, it would be ideal, actually, to check the antibodies before you reach that threshold of hyperglycemia and clinical diabetes. And so, ideally, if somebody’s a high-risk person with a family history or personal history of other autoimmune conditions, even checking in childhood would be the most beneficial, because this would lead to a lot more time for the education and prevention of DKA,” she said.

Studies have shown that when people get diagnosed with Type 1 diabetes, their condition is much better controlled, she noted. And if someone is positive for two of the antibodies indicative of Type 1 diabetes, they can qualify for specific treatments that can help delay the need for insulin, according to Eytan.

Accuracy

Eytan said when tests show that a patient has two or more antibodies indicative of Type 1 diabetes, there’s an almost 100% chance of conversion to hyperglycemia in their lifetime. Eytan said that clinicians should have a low threshold for rechecking antibodies if they suspect a patient has Type 1 diabetes. Levels can wax and wane, and may flip from positive to negative when patients become hyperglycemic, according to Eytan. She also said that her practice will recheck antibodies to confirm a diagnosis.

Awareness and education

Eytan called for increasing awareness of the possibility that a Type 2 diabetes diagnosis might be wrong. “If somebody’s presenting with a Type 2 diagnosis, oftentimes nobody questions that and just continues on the path or changes the medications,” she said. Eytan said commercial labs can easily check for the Type 1 antibodies, so setting up systems in the office that simplify ordering tests is helpful. Brixner agreed that education and awareness are important for providers and payers. She noted that patients with Type 2 diabetes may have some reservations about being diagnosed with Type 1 diabetes. “I think patients know Type 1 is a diagnosis of insulin and injections and a very different treatment pathway. So, there may be some resistance to that willingness to recognize that they may truly [have] type 1 [diabetes],” she said.