CAD Patients Show ‘High Disease Burden’ Based on Healthcare Use

People with cold agglutinin disease (CAD) use more healthcare resources than people without the disorder, both before and after a diagnosis, according to a recent Danish study.

Study findings indicated that six months before a CAD diagnosis, patients were three times more likely to be admitted to a hospital and six times more likely to have an outpatient clinic visit. Within 12 months of being diagnosed, the odds of needing a blood transfusion were 93 times higher in people with CAD.

The study, “Healthcare resource utilization among patients with cold agglutinin disease in Denmark,” was published in the journal Current Medical Research and Opinion.

CAD is a rare autoimmune disorder in which the body’s immune system starts producing antibodies that wrongly bind and destroy red blood cells at cold temperatures. This results in anemia and disease symptoms like fatigue, joint pain, and Raynaud’s syndrome — a condition that causes blood vessels to constrict.

The disorder is divided into two types, primary and secondary CAD. While in primary CAD the cause of the disease is unknown, secondary CAD develops as a result of an underlying condition.

Previous studies have reported that healthcare resource utilization (HRU) among patients with CAD is high in the U.S. However, until now, no study has assessed HRU among CAD patients in Europe.

Investigators in Denmark, along with colleagues in the U.S., reported the findings of the first study “to examine HRU of newly diagnosed CAD patients in a European population.”

Researchers identified CAD cases recorded in the Danish National Patient Registry (DNPR) from January 1, 1999, to June 30, 2016. Identified patients were then matched with the general population based on birth year, sex, and 19 disease categories of the Charlson Comorbidity Index (CCI). The CCI estimates a patient’s survival rate based both on the number and severity of co-existing medical conditions, known as comorbidities.

A group of primary CAD patients was also identified by excluding known causes of secondary CAD, such as those associated with B-cell lymphoma and Waldenström macroglobulinemia, as well as with infections caused by the Epstein-Barr virus, cytomegalovirus, and Mycoplasma pneumoniae.

Hospital admissions, outpatient clinic visits, emergency room visits, transfusion use, and expensive medication use were compared between groups six months before and 12 months after the index date — defined as the date of the first hospital admission or outpatient clinic visit with a CAD diagnosis.

A total of 104 CAD patients were identified and matched to 1,003 controls. Patients’ median age was about 72 for both groups, and more than half of those in the CAD group were women (53%).

Most patients had more than one comorbidity. Also, 64% of CAD patients and 60% of those with primary CAD had a CCI score of one or higher. Higher scores are associated with a more severe condition and a worse prognosis.

Within 12 months of the index date, a higher proportion of CAD patients were admitted to the hospital compared with matched controls (53% vs. 23%).

The likelihood of having at least one inpatient admission was nearly four times higher for CAD patients than for people from the general population. Additionally, the rate of inpatient hospital admissions rose by more than five times in CAD patients compared with matched controls.

More patients with CAD had at least one outpatient visit during the 12 months after the index date, compared with matched controls (95% vs. 59%). The odds of having at least one such visit were approximately 17 times higher for people with CAD.

Blood transfusions were higher for CAD patients than for controls (43.3% vs. 1.3%), with these patients being 93 times more likely to receive a transfusion in the 12 months following their index date. CAD patients also used expensive medications more often than controls (11% vs. 1%).

Likewise, HRU in the six months before the index date was higher for CAD patients. Before being diagnosed with CAD, patients had more inpatient admissions, outpatient visits, and emergency room visits when compared with matched controls.

The odds of having at least one inpatient admission in the six months preceding diagnosis was more than three times higher for CAD patients than for controls. These patients were also around six times more likely to visit an outpatient clinic before diagnosis than were controls.

HRU by primary CAD patients was similar to all those with CAD. Inpatient and outpatient visits, emergency room visits, and transfusion use were all higher in CAD patients relative to the general population.

“This study shows that patients with CAD utilize significant resources in Denmark,” the researchers wrote.

“The results of this study demonstrate that compared with a matched non-CAD [group] from the general population, patients with CAD utilize significantly more healthcare resources both prior to diagnosis and 1 year post-diagnosis,” they added. “The burden of disease among these patients is suggestive of unmet needs in earlier management of the condition.”