Health-Related Quality of Life and Disease Impacts in Adults with Transfusion-Dependent β-Thalassemia: Preliminary Results from the Global Longitudinal Survey

Abstract

Introduction: Transfusion-dependent β-thalassemia (TDT) is a chronic inherited blood disorder requiring frequent red blood cell transfusions and daily iron chelation therapy. Health-related quality of life (HRQoL) of individuals with TDT is impacted by a multitude of factors, including iron overload-related morbidity, substantial time required to manage TDT, and work and activity impairments. Nonetheless, the HRQoL impact of TDT is not well quantified. Here, we report the preliminary findings from a prospective longitudinal study evaluating the HRQoL and work productivity impacts among adult participants with TDT. Methods: A mixed-methods study was conducted to quantify the symptoms, HRQoL, and work and education impacts of adults with TDT. The study consisted of qualitative interviews and an online longitudinal survey administered at 3 timepoints (time 0, 3 months, 6 months) in the US, the UK, France, Germany, and Italy. The survey aimed to quantify the HRQoL impacts using multiple patient-reported outcomes measures (PROMs): the Functional Assessment of Cancer Therapy-Bone Marrow Transplant (FACT-BMT), composed of the Functional Assessment of Cancer Therapy-General (FACT-G) and a BMT subscale (BMTS); EuroQol 5-Dimension 5-Level (EQ-5D-5L); Transfusion-dependent Quality of Life (TranQoL); and Work Productivity and Activity Impairment (WPAI) questionnaire. Symptoms, comorbidities, treatment experiences, out-of-pocket costs, and time spent managing TDT were also collected and evaluated. Survey invitations were sent to patient communities via patient advocacy groups. Participants were required to meet the eligibility criteria and provide consent. Eligibility criteria included receiving ≥8 blood transfusions/year in each of the 2 years prior to enrollment. Descriptive analyses were conducted for participant characteristics and PROMs based on survey findings at time 0. Results: The survey was completed by 155 adult participants with TDT (aged ≥18 years) living in the US (n=83) and the UK, Germany, France, and Italy (n=72). Overall, 65.8% (n=102) were female, the mean age was 38.5 years (standard deviation [SD]: 10.8 years), and 32.9% (n=51) had full-time employment (32 hours/week). Participants reported a mean of 18.7 (SD: 8.2) transfusions in the previous 12 months. The mean FACT-G score was 70.1 (SD: 19.0) (0-108 scale; 108=best HRQoL), which is lower than the US general population mean of 80.1 (SD: 18.1). The largest HRQoL impact was observed on the emotional well-being domain of the FACT-G (-21.9% relative change) (mean: 14.7 [SD: 4.4] compared with the US general population (mean: 9.9 [SD: 4.8]) (0-24 scale; 24=best HRQoL). Participants reported a mean EQ-5D-5L visual analog scale score of 67.1 (SD: 20.4), with 73.2% reporting pain/discomfort, 60.8% anxiety/depression, 46.4% mobility impairment, and 24.8% self-care impairment. The mean TranQoL total score was 53.9 (SD: 18.5) (100-point scale; 100=best HRQoL). Forty percent of the participants felt that TDT limited their career opportunities "often” or "always.” Participants reported spending substantial time managing their condition in the last month, with 62.4% spending >6 hours at medical appointments and 36.1% needing >6 hours of care from family members/caregivers to manage their condition. Among those employed (n=84), 34.4% (SD: 30.9%) reported work impairment (presenteeism), 19.5% (SD: 25.5%) absenteeism, and 41.7% (SD: 32.4%) work productivity loss on the WPAI. Among all respondents (n=151), the mean activity impairment was 44.2% (SD: 31.0%). Results were consistent in a subset of 18-to-35-year-old participants. Conclusions: Adults with TDT currently receiving treatment experience significant HRQoL impacts and impaired work productivity and spend considerable time managing their disease, indicating significant humanistic burden and unmet needs in this patient population.