CAD Places ‘Substantial Burden’ on Patients, Healthcare Resources in US, Study Reports

Commercially insured patients with cold agglutinin disease (CAD) in the U.S. use healthcare resources — hospital admissions, outpatient and emergency room visits, and blood transfusions — more frequently than a matched group of patients without the disease, a large real-world study reports.

This utilization was also greater before diagnosis, suggesting that better diagnostic practices and improved awareness are needed to identify the condition at earlier stages.

The study, “Healthcare resource utilization among commercially insured patients with cold agglutinin disease in the United States,” was published in the Journal of Medical Economics.

In people with CAD, exposure to cold temperatures induces autoantibodies (antibodies directed against the body’s own tissues) to bind tightly to red blood cells, causing their disintegration and leading to anemia.

The disease has no approved treatments in the U.S. and in Europe, and therapies used for other autoimmune conditions have led to only minor benefits or are associated with serious side effects.

Given CAD’s rarity and the lack of specific diagnostic codes for the disease — which help researchers identify CAD cases in databases — data on the use of healthcare resources by these patients are still scarce.

A study published in 2017 has shown that most CAD patients require at least one hospital admission and outpatient visit within the first year of diagnosis. But no studies have compared their use of healthcare resources to that of the general population.

To address disease burden among these patients, researchers at Sanofi, EpidStrategies, and Beta6 Consulting Group joined efforts to investigate the use of healthcare resources among CAD patients diagnosed from January 2006 to June 2016.

Patient data was collected from the Optum-Humedica database, which contains information on medications, lab results, diagnoses, and procedures across commercially insured patients in all 50 U.S. states. CAD cases were identified by the presence of disease-related terms in clinical notes on at least three separate assessments.

To be included in the study’s data, patients were required to have at least six months of follow-up before and after their diagnosis (or first CAD mention).

In total, the analysis included 410 CAD patients and 3,390 people without CAD (the control group) matched by sex, age, year of entry in the database, race, region of residence, comorbidities, and follow-up time.

Patients had a median age of 71.5 years, most were women (62%) and white (87%), and nearly half were from the Midwest (46%). On average, both patients and controls were followed for 89 months (nearly 7.5 years), with about three of those years being after diagnosis.

Compared to the control group, insured CAD patients had a higher incidence of disorders such as cancer (46.6% vs. 24.8%), mild liver disease (16.8% vs. 12.2%), and connective tissue or rheumatic disease (13.9% vs. 6.9%), but a lower incidence of diabetes with complications (9.3% vs. 13.9%) and without complications (24.9% vs. 37.9%).

In the year after diagnosis, people with CAD had significantly more inpatient admissions (0.83 vs. 0.25 for the control group), outpatient visits (17.26 vs. 6.77), and days with blood transfusions per patient (1.05 vs. 0.05).

This was also true in the six months preceding diagnosis, when patients required a mean of 0.37 hospital admissions compared to 0.1 for the control group, and needed more than twice as many outpatient visits than controls (6.4 vs. 2.92). They also more frequently used emergency room services (17% vs. 9%), and had a higher mean number of transfusion days per patient (0.35 vs. 0.01).

“The results of this study demonstrate that patients with CAD have high HRU [healthcare resource utilization] before and after index date, placing a substantial burden on patients and healthcare systems, and suggest that improved disease awareness and diagnostic practices may be needed,” the researchers wrote.

Results remained significant when researchers examined only patients and controls without any additional diseases to avoid potential confounding. According to the team, the persistence of a higher healthcare use in this group “indicates that our findings cannot be solely owing to the presence of underlying comorbidities or other related disorders.”

The team added that the study included only commercially insured CAD patients, which may not represent the entire CAD population. Still, the findings help further understanding of a rare disease for which sufficient data are difficult to obtain, the scientists said.