33. Exploring Social Determinants of Health in Primary Immunodeficiency Patients Undergoing Immunoglobulin Replacement Therapy

Background: Primary immunodeficiency disorder (PIDD) is characterized by absent or dysfunctional antibodies, compromising the body’s ability to combat infections and increasing susceptibility to autoimmune, autoinflammatory, and malignant conditions. The standard treatment for PIDD is immunoglobulin replacement therapy (IRT), which requires lifelong administration and primarily addresses the immune deficiency aspect of the disorder. However, individuals with PIDD frequently experience significant challenges that extend beyond their medical condition, affecting their physical and mental health, academic progress, and social engagement.

Social determinants of health (SDOH) are crucial in shaping health outcomes for individuals with PIDD. SDOH encompasses a range of factors, including health behaviors, socioeconomic conditions, environmental influences, and access to clinical care, collectively contributing to approximately 80% of overall health outcomes. While research has increasingly recognized the importance of SDOH in healthcare access and treatment initiation, there is a notable gap in understanding their ongoing influence on long-term patient care and treatment adherence. Existing studies often focus on barriers to initiating IRT, yet limited data existexists on how these social and economic factors continue to impact patients receiving chronic therapy.

This study seeks to address this gap by examining the persistent influence of SDOH on individuals with PIDD undergoing IRT. By utilizing a survey adapted from the validated PRAPARE tool, the research will assess key factors such as insurance coverage, socioeconomic status, education, geographic location, transportation access, social support, mental health, and primary language.

Purpose: The primary aim of this study is to evaluate the ongoing impact of SDOH on individuals with PIDD who are currently receiving IRT. Using responses from the validated 28-item PRAPARE questionnaire, this study will characterize these factors within our patient population. We hypothesize that despite access to pharmacologic therapy, SDOH remain a significant influence on patient care. The findings from this study will serve as a foundation for developing targeted protocols within our pharmacy to better address health determinants and optimize long-term treatment outcomes.

Methods: This cross-sectional, descriptive study received exempt IRB approval. Eligible participants were identified through electronic health records and included adults (≥18 years) diagnosed with specific immunodeficiencies based on ICD-10 codes. Patients who were < 18 years, deceased, or did not have a qualifying immunodeficiency diagnosis were excluded. Recruitment was conducted via telephone, and informed consent was obtained. Each patient was contacted up to two times; if there was no response, they were excluded. Data collection occurred from February 24, 2025, to March 3, 2025. The target sample size was 100 participants. Data were all stored securely and descriptive statistics were used for analysis.

Results: A total of 193 patients were assessed for eligibility and assigned a randomized order for contact. Of these patients, 116 responded (60.1%), 81 (42%) agreed to participate, and 35 declined. Seventy-seven patients (39.9%) did not respond and were excluded. Among the 81 participants, 56 (69.1%) completed the survey in full, while 25 (30.9%) provided incomplete responses, primarily omitting questions related to household income, employment, or insurance status. The survey took approximately 5–7 minutes to administer.

Key demographic findings included insurance coverage, with 35 (43%) participants reporting private insurance, 18 (22.2%) reporting Medicare, and 14 (17.3%) reporting Medicaid as their primary coverage. Social support appeared strong, as 41 (50.6%) of participants reported speaking with loved ones at least six times per week, 19 (23.5%) three to five times per week, and 14 (17.3%) up to twice weekly. Transportation barriers were minimal, with only 2 (2.7%) participants lacking overall access and 1 (1.2%) explicitly reporting difficulty accessing transportation for medical appointments. However, 19 (23.5%) participants faced challenges obtaining essential resources such as medical supplies, utilities, or food. Stress levels varied, with 26 (32.1%) participants reporting “a little bit of stress” and 23 (28.4%) indicating they were “somewhat stressed.” Employment status differed among respondents, with 46 (56.8%) unemployed and not actively seeking work, while 23 (28.4%) reported full-time employment. Educational attainment was relatively high, with 61 (73.3%) participants having education beyond high school and 18 (22.2%) respondents reporting graduating high school as their highest level of schooling.

Discussion: This study aimed to assess the prevalence of SDOH in individuals receiving IRT for PIDD. Key findings from the survey highlight several important considerations regarding ongoing patient care and social factors that influence health outcomes.

One of the most striking findings is the high survey completion rate (69.1%), which suggests that integrating similar surveys into routine clinical workflows is feasible and could be beneficial in identifying barriers to care. Given its brevity and ease of administration, this survey could be integrated into the initial phase of clinical pharmacy interactions or used throughout the continuum of care. This could ultimately contribute to the development of protocols that address these barriers and improve health outcomes for patients with PIDD. Another promising finding is this population’s relatively strong social support network. With 50.6% of participants reporting that they spoke with loved ones at least six times per week, this could act as a protective factor, potentially reducing the negative impact of SDOH on overall well-being. The relatively high education level of participants (73.3% with education beyond high school) suggests that this population may have a more potent health literacy, which could influence adherence to IRT and self-management of their condition. However, despite this strong social network and high education level, economic hardship remains a significant challenge, with 23.5% of participants struggling to obtain essential resources like medical supplies, utilities, or food.

The study also highlights the varying stress levels within the cohort. While the majority reported low to moderate stress, the 32.1% who reported “a little bit of stress” and the 28.4% who felt “somewhat stressed” suggest that stress may still play a role in exacerbating health challenges, especially for individuals managing chronic conditions. These findings point to the need for targeted mental health interventions or support services to complement ongoing medical care.

While the findings provide valuable insights, the study does have several limitations. First, the small sample size (81 participants) and the limited data collection period may not represent the broader population of patients with PIDD. A more extended data collection period might have allowed for a larger sample size and could have increased the number of responses, potentially yielding more comprehensive data. Additionally, the fact that 39.9% of patients did not respond to recruitment efforts could introduce selection bias, as those who chose not to participate might have differing experiences of SDOH compared to those who participated.

Furthermore, the study relied on telephone interviews to collect survey responses, which could introduce misinterpretation bias in the administration of the questions and in the accuracy of participant responses. Patients who may have had difficulty understanding the questions or those with communication barriers (e.g., hearing impairment or language differences) could have been underrepresented in the results. While verbal consent was obtained, the lack of face-to-face interaction may have influenced the quality of the data.

Conclusions: In conclusion, this study sheds light on the ongoing impact of SDOH on patients with PIDD receiving IRT. The findings suggest that integrating this type of survey into routine clinical practice could help promptly identify and address barriers to care. However, future research should consider expanding the study period, including a more diverse cohort, and using different data collection methods to ensure a more comprehensive understanding of how SDOH influences health outcomes over time.