Ethnic and socioeconomic disparities affect outcomes in ALL

16th December 2021

Ethnic and socioeconomic disparities lead to differences in survival according to a large study of acute lymphoblastic leukaemia

Ethic and socioeconomic disparities in survival outcomes have been highlighted in an analysis of newly diagnosed children and young adults with acute lymphoblastic leukaemia (ALL). This was the main finding from a study by researchers from Institute for Health Policy, Evaluation and Management, University of Toronto, Canada, presented at ASH 2021.

Health disparities are major issue for racial, ethnic, and socioeconomically disadvantaged groups and although outcomes in childhood ALL have steadily improved, disparities based on ethnicity and socioeconomic (SES) factors appear to persist.

For the present study, the Canadian team sought to identify the presence of any persistent inequities by race/ethnicity and SES in childhood ALL in the largest cohort ever assembled for this purpose. They identified a cohort of newly-diagnosed patients with ALL, ranging in age from 0 to 40 years enrolled in trials between 2004-2019. Race/ethnicity was categorised as non-Hispanic white vs. Hispanic vs. non-Hispanic Black vs. non-Hispanic Asian vs. Non-Hispanic other.

SES was proxied by insurance status: United States (US) Medicaid (public health insurance for low-income individuals) vs. US other (predominantly private insurance) vs. non-US patients (mainly jurisdictions with universal health insurance). Event-free and overall survival (EFS, OS) were compared across race/ethnicity and SES. The relative contribution of disease prognosticators (age, sex, white blood cell count, lineage, central nervous system status, cytogenetics, end Induction minimal residual disease) were examined with Cox proportional hazard multivariable models of different combinations of the three constructs of interest (race/ethnicity, SES, disease prognosticators) and examining hazard ratio (HR) attenuation between models.

Findings

The study cohort included 24,979 children, adolescents, and young adults with ALL. A total of 13,872 (65.6%) of the whole cohort were Non-Hispanic White patients, followed by 4354 (20.6%) Hispanic patients and 1517 (7.2%) non-Hispanic Black patients. Those insured with US Medicaid were 6944 (27.8%).

The 5-year EFS was 87.4% among non-Hispanic White patients vs. 82.8% among Hispanic patients (hazard ratio, HR = 1.37, 95% CI 1.26 – 1.49; p<0.0001] and 81.9% among non-Hispanic Black patients. The outcomes for non-Hispanic Asian patients were similar to those of non-Hispanic White patients.

US patients on Medicaid had inferior 5-year EFS as compared to other US patients (83.2% vs. 86.3%, HR = 1.21, 95% CI 1.12 – 1.30, p<0.0001) while non-US patients had the best outcomes, with a 5-year EFS of 89%.

There was substantial imbalance in traditional disease prognosticators (e.g. T-cell lineage) across both race/ethnicity and SES, and of race/ethnicity by SES. For example, T-lineage ALL accounted for 17.6%, 9.4%, and 6.6% of Non-Hispanic Black, Non-Hispanic White, and Hispanic patients respectively (p<0.0001).

Multivariable analysis showed how EFS among Hispanic patients was substantially attenuated by the addition of disease prognosticators and the hazard ratio reduced from HR 1.37 to 1.17 and was further (but not fully) attenuated by the subsequent addition of SES (HR 1.11).

In contrast, the increased risk among non-Hispanic Black children was minimally attenuated by both the addition of disease prognosticators and subsequent addition of SES (HR reduction of 1.45 to 1.38 to 1.32). Similarly, while the superior EFS of non-US insured patients was substantially attenuated by the addition of race/ethnicity and disease prognosticators (HR 0.79 to 0.94), increased risk among US Medicaid patients was minimally attenuated by the addition of race/ethnicity or disease prognosticators (HR 1.21 to 1.16).

OS disparities followed similar patterns but were consistently worse than in EFS, particularly among patients grouped as non-Hispanic other.

The authors concluded that there were substantial disparities in survival outcomes by race/ethnicity and SES and that these disparities varied between specific disadvantaged groups., adding that future studies are required to identify specific drivers of survival disparities that may be mitigated by targeted interventions.

Citation

Gupta S et al. Racial, Ethnic, and Socioeconomic Factors Result in Disparities in Outcome Among Children with Acute Lymphoblastic Leukemia Not Fully Attenuated By Disease Prognosticators: A Children’s Oncology Group (COG) Study. ASH Conference 2021

Higher diet quality associated with lower risk of COVID-19

17th September 2021

Poor metabolic health leads to worse outcomes in COVID-19 but a higher diet quality appears to reduce the risk and severity of infection.

The presence of poor metabolic health in conditions such as obesity and type 2 diabetes is known to be associated with worse outcomes in COVID-19. In fact, a higher body mass index has been found to be a causal risk factor for COVID-19 susceptibility and severity. Obesity is influenced by dietary intake but an important factor is the quality of an individual’s diet so that a higher diet quality is associated with a lower risk of obesity. Various measures have been developed to evaluate diet quality and how this can impact on the risk of chronic diseases. One such diet score is the healthful Plant-Based Diet Index (HPBDI) and which has been associated with a lower risk of developing type 2 diabetes. However, the association between diet quality and both the risk and severity of COVID-19 is less clear.

In light of this evidence gap, a team led by researchers from Harvard Medical School, Boston, US, decided to explore the relationship between diet quality and COVID-19. The team used data obtained from a smartphone app used for the COVID-19 Symptom Study to prospectively investigate the association. As well as diet, the team sought to examine how the risk of COVID-19 depends on not only on diet quality but also socioeconomic deprivation. Demographic and clinical data were collected via the smartphone app between March and December 2020, together with self-reported COVID-19 testing and symptoms. Diet quality was obtained using a short-form food frequency questionnaire and participants were asked to report how often on average, they consumed one portion of particular foods in a typical week. Using this information, the team calculated a HPDI score which ranged from 14 (lowest) to 70 (highest) with higher scores reflecting a healthier plant-based diet. Individuals were then categorised as having a low, medium or high HPDI score. The primary outcome was COVID-19 risk based on a predictive, symptom-based algorithm and multivariable Cox models were used to calculate hazard ratios (HR) for COVID-19 risk and severity.

Findings
Self-reported diet quality was available for 592,571 app users with a mean age of 56 years (68.2% female), of whom, the vast majority (96%) were of White ethnicity and the mean HPDI score for the whole sample was 50. In fully adjusted models, for individuals with the highest HPDI score compared to the lowest score, the risk of COVID-19 was reduced by 9% (HR = 0.91, 95% CI 0.88 – 0.94, p < 0.001). Furthermore, the risk of severe COVID-19 was also significantly reduced for those with the highest HPDI compared to the lowest HPDI scores (HR = 0.59, 95% CI 0.47 – 0.75, p < 0.001).

When considering socioeconomic deprivation, there was clearly an association between an increased risk of COVID-19 and diet quality. For example, among those living in an area of low deprivation and with a low HPDBI score, the risk of COVID-19 was slightly elevated (HR = 1.08, 95% CI 1.03 – 1.14). However, among those with a low HPBDI scores and living in an area of high deprivation, the risk was much higher (HR = 1.47, 95% CI 1.38 – 1.52). In fact, even among those with a high HPBDI but living in a highly deprived area, the risk of COVID-19 was still elevated (HR = 1.28, 95% CI 1.18 – 1.37, p < 0.001).
The authors concluded that a higher diet quality was associated with a reduced risk of both COVID-19 and severe disease but also that the combination of poor diet and increased socioeconomic deprivation further increased COVID-19 risk.

Citation
Merino J et al. Diet quality and risk and severity of COVID-19: a prospective cohort study. Gut 2021