Immunoglobulin (Ig) replacement therapy (IgRT) has been shown to be an effective course of treatment for patients with primary or secondary immunodeficiencies. The infusion methods used to administer this course of treatment are intravenous (IVIg) and subcutaneous (SCIg), and studies have shown that the method selected can potentially affect the patient’s treatment-related burden and outcome.
Paul Bassett, MSc, and colleagues sought to evaluate treatment satisfaction among patients receiving IVIg compared with patients receiving SCIg. As Bassett and colleagues wrote in Allergy, Asthma & Clinical Immunology, “Regular long-term treatment regimens, while reducing disease burden, can introduce treatment-related burden in terms of interference with daily life, increased risk for adverse events [AEs], and acting as a constant reminder of the disease. Studies have demonstrated that reduced treatment complexity and duration can decrease treatment burden and have a positive impact on patient compliance and [QOL].”
Bassett and colleagues used Canadian Immuno-deficiencies Patient Organization (CIPO) and Association des Patients Immunodéfcients du Québec (APIQ) survey data to identify patients with immunodeficiencies. They reached out via email to request their participation in an incentivized online survey containing 101 questions on igRT and their experience with its administration. The survey also included questions on demographic characteristics, choice of infusion method, characteristics of chosen infusion method, history of IgRT, switching between IVIg and SCIg, SCIg training issues, and structured patient-reported
outcomes (PROs).
Majority of Patients Reported Using SCIg
Patients were excluded from the study if they were younger than 18 or failed to report their age, were not currently receiving IgRT, or if their responses were incomplete or conflicting. Participants were stratified based on their current IgRT infusion method as well as their IgRT history, forming the following two main cohorts: IVIg cohort and SCIg cohort. The second of the two was then stratified into two sub cohorts; 65 of the SCIg cohort were designated as SCIg naïve, meaning that they never used Ig, and 151 of the SCIg cohort were designated as SCIg switch, meaning that they were switched from IVIg to SCIg.
Of the 327 participants selected for the study, 16.5% indicated that IVIg was their current method of infusion and 74% indicated that SCIg was their current method of infusion.
In the IVIg cohort, the most common reason (43.5%) for patient choice was “maintaining steady levels for treatment (IgG) in the person’s blood,” The most common reason in the SCIg cohort (34.5%) was “ability to self-infuse (Figure).”
An unfavorable impact of the treatment regimen on work/school attendance was reported more frequently in the IVIg cohort compared with the SCIg cohort (33.3% vs 8.3%; P<0.001). The median duration of the actual infusion was reported to be significantly shorter in the SCIg cohort compared with the IVIg cohort (60 mins. vs 165 mins., respectively; P<0.001).
SCIg Cohort Scored Higher in ‘Effectiveness’ Than IVIg Cohort
On survey questions drawn from the Treatment Satisfaction Questionnaire for Medication (TSQM-9) on effectiveness, participants in the SCIg cohort scored significantly higher than the IVIg cohort (P=0.02). Specifically, the SCIg cohort reported greater satisfaction with the amount of time it takes the medication to start working compared with the IVIg cohort (P<0.001).
In both the IVIg cohort and the SCIg cohort, the prescriber was most often identified as the person impacting the patient’s chosen method of infusion; this was more prominent in the SCIg cohort (67.8% vs 52.1%). Participants who switched from IVIg to SCIg reported in most cases that the stakeholder responsible for the switch was also the prescriber (70%).
Of the participants who switched from IVIg to SCIg, 81.5% described an improved or substantially improved QOL, and 33.1% reported substantial improvement. Following the switch, 58.1% of participants reported better physical health, and 44.4% reported improved or substantially improved mental health.
Given the results of the study, a patient’s access of treatment may have an impact on their adherence, which may lead to positive outcomes. “In general, patient preference assessments have highlighted the importance of continually offering patients information and a choice of IgRT infusion options,” Bassett and colleagues wrote. “In addition to training, clinical support and shared decision making are critical, even if patients have been satisfied [with] one type of IgRT infusion method for many years.”
