Clinical profiles of hemophilia B range from mild to severe forms of the disease. Prior studies have investigated the economic burden of hemophilia B, but focused on outcomes within the overall study sample, without stratifying by disease severity or clinical profile. The present study sought to develop an algorithm to identify clinical profiles of hemophilia B for burden of illness assessment, based on indicators that are observable in US payer claims databases.
Adult (≥18 year-old) male patients with ≥2 diagnoses of hemophilia B were identified from the Marketscan Commercial and Medicare Supplemental Databases (06/2011−02/2019). For each patient, an index date was randomly selected among all hemophilia B diagnosis dates meeting the requirement of continuous enrollment for 1 year pre-index (baseline) and 1 year post-index (study period). Clinical profile was categorized as severe, moderate-severe, moderate, or mild based on frequencies of FIX replacement claims and hemorrhage events at baseline. The selection of profile indicators was informed by literature and clinical expert opinion. To assess the discriminatory ability of the algorithm, healthcare costs were summarized by clinical profile during the study period.
A total of 454 patients were included (mean age: 46 years). At baseline, the algorithm classified 66 (15%) as severe [≥6 FIX claims], 69 (15%) as moderate-severe [4-5 FIX claims, or ≤3 FIX claims and ≥1 hemorrhage], 118 (26%) as moderate [1-3 FIX claims and no hemorrhage], and 201 (44%) as mild [no FIX claims or hemorrhage]. During the study period, mean total healthcare costs were higher among patients identified as having more severe profiles (severe: $643,979; moderate-severe: $254,077; moderate: $141,101; mild: $83,291).
The hemophilia B clinical profile algorithm developed in this study identified four subgroups with increasing healthcare costs according to severity. The development of the first claims-based algorithm to identify clinical profiles creates opportunities to expand potential uses of US payer claims databases for understanding disease burden and unmet medical needs in hemophilia B.