AIP Patients Use Fewer Healthcare Resources When They Take Hemin as Preventive Therapy, US Study Reports

Patients with acute intermittent porphyria (AIP) who take hemin as preventive therapy use fewer healthcare resources than those who take the medicine for acute attacks, according to a study based on U.S. real-world data.

The study, “Real-world annualized healthcare utilization and expenditures among insured US patients with acute intermittent porphyria (AIP) treated with hemin,” was published in the Journal of Medical Economics.

AIP is a genetic metabolic disorder caused by mutations that impair the production of hydroxymethylbilane synthase, enzymes involved in the production of heme, the substance inside red blood cells that binds and carries oxygen throughout the body.

Patients with AIP experience acute symptoms that vary in severity and include abdominal pain, nausea, vomiting, and constipation. These symptoms often lead to hospitalizations or emergency room (ER) visits but their unspecific nature can lead to difficulties in diagnosing AIP.

While 3% to 5% of patients have recurrent, severe attacks, the symptoms are similar in patients with and without recurrent disease. Hemin is usually administered in the event of an acute porphyria attack but patients can also be given hemin as a preventive, off-label treatment for recurrent attacks.

Prophylactic treatment with hemin may also result in lower healthcare costs while helping to improve the quality of life for patients. However, annual estimates of disease-related costs are limited. In one case study, the average direct hospital costs were reduced by 25% for two patients after they started preventive treatment with hemin. Expenses related to hemin made up 63% of the average direct costs.

In the retrospective, observational study, the aim was to use real-world data to estimate annual healthcare use and expenditures for AIP patients treated with hemin in the U.S.

The researchers analyzed data from the IBM MarketScan Commercial and Medicare pharmacy and medical claims databases collected from 2007 to 2017. The MarketScan database includes the total cost of care (such as inpatient, outpatient, therapy, and laboratory) for many patients in the United States with commercial and Medicare supplemental insurance. In the analysis, costs were inflated to 2017 values.

The primary analysis included 139 patients (34 with AIP and 105 diagnosed with acute porphyria) who received hemin and were continually followed for at least six months.

The patients were mostly women (112 patients, 81%), 40 years old on average, with an average three years’ follow-up. Patients were sub-divided into those who received primary acute treatment (54 patients) and preventive treatment (85 patients).

“The acute treatment sub-group was defined by a pattern of intermittent, daily hemin use associated with attacks. The prophylaxis sub-group was defined by monthly or other scheduled doses of hemin (i.e. weekly and bi-weekly) for at least 10 months in a 12-month period,” the researchers wrote.

In a second analysis, the researchers analyzed the “active disease population,” a total of 27 patients who had three or more attacks or at least 10 months of preventive treatment of hemin within a 12-month period, but also who had 12 months of continuous follow-up. The patient characteristics were similar to the patients included in the primary analysis.

The researchers found that the annual average total costs were $113,477 for AIP-related care, and $188,752 for all-cause (any diagnosis) healthcare, with the largest costs being outpatient expenses. The annualized costs were lower for the preventive subgroup compared to the acute treatment subgroup, although this was not significantly different. The average annual cost for hemin was $44,223 for treatment of attacks and $88,964 for preventive therapy.

On average, AIP patients treated with hemin visited the hospital 1.4 times a year with an average hospital stay of 5.5 days. The annual average healthcare resource utilization for any diagnosis was significantly lower in patients receiving preventive treatment of hemin compared to those receiving acute treatment. This included hospitalizations, ER visits, primary care visits, home services, and other outpatient services.

When limited to AIP-related utilization, patients receiving preventive treatment had significantly lower annualized mean hospitalizations and other outpatient services compared to the acute treatment group, but ER visits and home services were similar, and primary care visits and specialist visits were significantly greater.

Among AIP patients treated with hemin with active disease, the average total healthcare costs was $280,405 for all-cause (any diagnosis) and $187,480 for AIP-related care. Again, the greatest costs were for outpatient expenses. The average annual cost for hemin was $66,374 for acute treatment and $127,297 for prophylaxis treatment. These patients visited the hospital 1.5 times a year with an average hospital stay of 5.3 days.

Overall, “AIP patients treated with hemin use a wide range of healthcare resources, and patients treated for acute attacks may use a greater number of resources compared to patients treated prophylactically,” the study said.