Socioeconomic Status and Overall Survival Among Patients With Hematological Malignant Neoplasms

Abstract

Importance: In recent years, there has been a focus on reducing the socioeconomic gap in survival for hematological malignant neoplasms. Understanding recent developments is important to develop further intervention to improve care.

Objective: To investigate the temporal trend in associations of socioeconomic status (SES) with survival among 3 aggressive hematological malignant neoplasms: multiple myeloma (MM), acute myeloid leukemia (AML), and diffuse large B-cell lymphoma (DLBCL).

Design, setting, and participants: This nationwide, population-based cohort study used retrospectively collected data from 3 clinical registries of patients diagnosed in Denmark between January 1, 2005, and December 31, 2020, with follow-up until December 31, 2021. Analyses were stratified by diagnosis year (2005-2009, 2010-2014, and 2015-2020). Participants were patients aged 25 to 65 years with hematological malignant neoplasms. Patients with missing data on education were excluded. Data were analyzed from October 14, 2022, to January 2, 2024.

Exposure: Education was used as a proxy for SES and defined low- and high-SES groups based on the completion of tertiary education.

Main outcomes and measures: The main outcome was overall survival (OS), analyzed using Kaplan-Meier (log rank) method and Cox proportional hazards regression adjusted for age, sex, performance status, comorbidities, and disease-specific prognostic indices. Two-year OS through time and survival difference were estimated using flexible parametric survival models.

Results: A total of 5677 patients (median [IQR] age, 58 [51-62] years; 3177 [57.0%] male) were assessed, including 1826 patients with MM, 1236 patients with AML, and 2509 patients with DLBCL. The 2-year OS increased over time for patients with MM (78.8% [95% CI, 75.4%-82.3%] to 91.4% [95% CI, 89.3%-93.5%]), AML (42.2% [95% CI, 37.8%-47.1%] to 52.7% [95% CI, 48.0%-57.9%]), and DLBCL (80.1% [95% CI, 77.4%-82.8%] to 88.1% [95% CI, 86.0%-90.3%]). For MM and DLBCL, no association of SES with survival was observed after adjustment (MM: hazard ratio [HR], 0.99 [95% CI, 0.85-1.15]; DLBCL: HR, 1.08 [95% CI, 0.91-1.29]). For AML, a negative association was observed between low SES and survival (HR, 1.49 [95% CI, 1.25-1.76]), but the association was attenuated in recent years. The difference in hazard for patients with low SES and AML was observed in the first 2 years after diagnosis.

Conclusions and relevance: These findings suggest that survival has improved among patients with these hematological malignant neoplasms. While patients with MM and DLBCL had increased survival in all groups, disparities were observed in AML outcomes, primarily in the first years after diagnosis. These results suggest that differences originate in factors specific to AML.

Figure 1.. Flowchart of Study Exclusion Criteria

The study includes patients with multiple myeloma (MM) from the Danish National Multiple Myeloma Registry (DMMR), patients with acute myeloid leukemia (AML) from the Danish National Acute Leukemia Registry (DNLR), and patients with diffuse large B-cell lymphoma (DLBCL) from the Danish National Lymphoma Registry (LYFO). CPR indicates Central Person Register.

Figure 2.. Overall Survival (OS) Probability by Socioeconomic Status (SES) and Year of Diagnosis

AML indicates acute myeloid leukemia; DLBCL, diffuse large B-cell lymphoma; and MM, multiple myeloma. P values are from log-rank tests. Censoring is indicated by vertical line. Shaded areas indicate 95% CIs.

Figure 3.. Estimated Hazard Ratios (HRs) From Univariable and Multivariable Cox Regressions for Socioeconomic Differences

HRs are estimated using patients with high socioeconomic status (SES) as reference. The confounder-adjusted model includes age and sex, and the mediator-adjusted model includes age, sex, performance score, comorbidity, and disease-specific prognostic index. AML indicates acute myeloid leukemia; DLBCL, diffuse large B-cell lymphoma; and MM, multiple myeloma.

Figure 4.. Estimated Socioeconomic Differences Using Flexible Parametric Survival Models

AML indicates acute myeloid leukemia; DLBCL, diffuse large B-cell lymphoma; and MM, multiple myeloma. Shaded areas indicate 95% CIs.