The overall goal of this study was to determine whether ethnic differences existed in the prevalence of chronic health conditions after HCT. While the CIBMTR report found that Hispanics had a 30% increased risk of early post-HCT events,7
others have failed to replicate these findings and have suggested that the differences in outcome may be less about ethnicity and more about socioeconomic status and barriers to healthcare access faced by these populations.16
Furthermore, in previous reports, BMTSS identified no ethnic/racial differences in late mortality due to non-relapse causes.5,6
There exists a paucity of data regarding the magnitude of long-term morbidity in Hispanic HCT survivors; whether there are differences in morbidity between non-Hispanic whites and Hispanics; and the possible causes of these differences. In the current study, we found that Hispanics are 53% less likely to report chronic severe/life-threatening/disabling conditions when compared with non-Hispanic whites after adjusting for relevant clinical variables an effect size that was mitigated after adjusting for known sociodemographic factors, most notably, health insurance coverage.
Availability of health insurance determines the timeliness and quality of healthcare received by survivors.9
Hispanics face greater barriers to health insurance access than all other racial/ethnic groups, making them less likely to have a regular source of care.9,17,18
The prevalence of being uninsured among Hispanics is 33% compared with 17% for the general population.9,19
The current study found Hispanics to be significantly more likely to be uninsured at study participation (24.5%) compared with non-Hispanic whites (6.3%). Those who had health insurance coverage were three-fold more likely to report a severe/life-threatening condition, independent of other modifying risk factors such as socioeconomic status, age, gender, and treatment-related conditions. In fact, having health insurance coverage was associated with a higher likelihood of diagnosis and reporting of severe/life-threatening/disabling health conditions following HCT in both
Hispanics and non-Hispanic whites. There are several reasons as to why having health insurance would increase the likelihood of reporting chronic health conditions: first, as shown by others, long-term cancer survivors who have health insurance are more likely to undergo recommended health-related screenings such as echocardiograms, mammograms and pap smears, thus increasing the likelihood of detection of the condition being screened.20–22
In fact, we have demonstrated in a previous study that lack of health insurance is associated with a lower prevalence of healthcare utilization by this cohort of HCT survivors.11
Second, availability of health-related resources and access to healthcare would presumably lead to improvement in health-related-knowledge, enabling these survivors to more accurately characterize the nature and severity of their chronic medical conditions.23,24
The paucity of information regarding these barriers in previous studies is likely due to the relatively small numbers of Hispanics included in studies evaluating long-term outcomes following HCT.7,16
For example, it is increasingly recognized that language proficiency plays an important role in health-related knowledge and access to primary care.9,25,26
With nearly 30% of Hispanics in the U.S. currently living in a linguistically isolated household,10
language proficiency is likely to play an increasingly important role in the design of studies evaluating long-term outcomes in these at risk populations. As highlighted in the recent American Society of Clinical Oncology (ASCO) Policy Statement on Disparities in Cancer Care,27
these issues need to be addressed comprehensively to develop support systems and informed interventions for the vulnerable sub-populations.
We also demonstrate that presence of active chronic GvHD increases the risk of chronic severe/life-threatening/disabling conditions. Chronic GvHD is a leading cause of non-relapse mortality and is associated with chronic renal toxicity, musculoskeletal abnormalities, cardiopulmonary compromise, and gastrointestinal complications.4,6,28–31
The current study summarizes the burden attributable to chronic GvHD, by demonstrating a 4-fold increased risk of severe/life-threatening health conditions among those with active chronic GvHD. Chronic health conditions reported include those that are well known consequences of chronic GvHD and its management, i.e., visual impairment, gastrointestinal complications, and musculoskeletal disabilities. Of note, the prevalence of active chronic GvHD did not differ by ethnicity in the current study.
Complications associated with TBI include renal insufficiency,30,32
and subsequent malignancies.42–44
Several of these conditions such as cataracts, chronic renal insufficiency, and pulmonary dysfunction are in turn exacerbated by chronic GvHD and its treatment. In the current study, individuals receiving TBI reported a nearly two-fold increased risk of severe or life-threatening chronic health conditions, independent
of chronic GvHD status.
The results of this study must be interpreted in the context of potential limitations. There was an overrepresentation of Hispanics among non-participants, potentially contributing to an underestimation of chronic health conditions in this population of survivors, if the non-participants were to have had a higher prevalence of chronic health conditions than participants. However, non-participants were younger at the time of HCT and at the time of survey, and were less likely to have received TBI – characteristics associated with a lower risk of chronic health conditions – suggesting that the non-participants should have been at a lower risk of developing these complications than the participants, and would therefore not have resulted in an underestimation of the prevalence.
Ethnic differences in mortality due to chronic health conditions prior to study participation could potentially have introduced bias in the prevalence of chronic health conditions reported by the survivors. However, we did not find ethnic/racial difference in non-relapse-related late mortality after HCT.5,6
We therefore believe that ethnic differences in deaths due to chronic health conditions would not have contributed to bias in the current study.
This study is designed to capture self-reported chronic health conditions diagnosed as a consequence of delivery of “standard care” after HCT. Large studies of cancer cohorts have shown that self-report can be used effectively to describe post-treatment complications that were diagnosed as part of routine healthcare delivery
Furthermore, we have demonstrated that HCT survivors have the ability to report post-HCT complications accurately12
– as long as they have been diagnosed, which depends on access to care, which in turn is dependent on availability of health insurance coverage.
This study was not designed to conduct a comprehensive evaluation of all HCT survivors to identify pre-clinical or clinically overt long-term complications – an approach that is needed to describe the burden of long-term morbidity in all patient populations – but is logistically and financially prohibitive in a large and geographically diverse cohort such as ours. On the contrary, this study summarizes the prevalence of chronic health conditions diagnosed by our healthcare system and communicated to the HCT survivors, taking into account issues related to health insurance coverage, access to care, awareness among the healthcare providers of the risk of long-term complications, and communication of these outcomes to the HCT survivors. Keeping these issues in mind, our study finds Hispanics to be less likely to report severe/life-threatening health conditions after HCT – a difference that decreases in magnitude and significance after taking health insurance into consideration. While confirming the role of TBI, and chronic GvHD, overall, this study identifies the role of health insurance coverage as a mediator of the lower prevalence of self-reported long-term morbidity in Hispanics.