Barriers to Hematopoietic Cell Transplantation for Adults in the United States: A Systematic Review with a Focus on Age

Hematopoietic cell transplantation (HCT) is an effective treatment for many hematologic malignancies, and its utilization continues to rise. However, due to the difficult logistics and high cost of HCT, there are significant barriers to accessing the procedure; these barriers are likely greater for older patients. Although numerous factors may influence HCT access, no formal analysis has detailed the cumulative barriers that have been studied thus far. We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to better categorize the barriers to access and referral to HCT, with a focus on the subgroup of older patients. We searched for articles published in English from PubMed, Embase, Cumulative Index for Nursing and Allied Health, and Cochrane Central Register of Controlled Trials between the database inception and January 31, 2020. We selected articles that met the following inclusion criteria: (1) study design: qualitative, cross-sectional, observational cohort, or mixed-method study designs; (2) outcomes: barriers related to patient and physician access to HCT; and (3) population: adults aged ≥18 years with hematologic malignancies within the United States. Abstracts without full text were excluded. QUALSYST methodology was used to determine article quality. Data on the barriers to access and referral for HCT were extracted, along with other study characteristics. We summarized the findings using descriptive statistics. We included 26 of 3859 studies screened for inclusion criteria. Twenty studies were retrospective cohorts and 4 were cross-sectional. There was 1 prospective cohort study and 1 mixed-method study. Only 1 study was rated as high quality, and 16 were rated as fair. Seventeen studies analyzed age as a potential barrier to HCT referral and access, with 16 finding older age to be a barrier. Other consistent barriers to HCT referral and access included nonwhite race (n = 16/20 studies), insurance status (n = 13/14 studies), comorbidities (n = 10/11 studies), and lower socioeconomic status (n = 7/8 studies). High-quality studies are lacking related to HCT barriers. Older age and nonwhite race were consistently linked to reduced access to HCT. To produce a more just health care system, strategies to overcome these barriers for vulnerable populations should be prioritized. Examples include patient and physician education, as well as geriatric assessment guided care models that can be readily incorporated into clinical practice.