Health Disparities in Melanoma Patients: Understanding the influence of 
comorbidities on overall survival among our poorest patient populations 
Amanda Rosenthal, MD1; Joanie Chung, MPH2; Robert Cooper MD3; Reina Haque, PhD2,4; Christina Kim, MD1

1 Department of Dermatology, Kaiser Permanente Los Angeles Medical Center, Los Angeles, CA; 2 Department of Research & Evaluation, Kaiser Permanente Southern California; 
Kaiser Permanente Los Angeles Medical Center (TH), Pasadena, CA; 3 Department of Pediatric Hematology/Oncology, Southern California Permanente Medical Group, Kaiser 
Permanente Los Angeles Medical Center, Los Angeles, CA; 4 Department of Health Systems Science, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, CA 

No authors have any financial relationships to disclose. 

CONCLUSION
• We demonstrate an 18% increased risk of death among our poorest melanoma patients that cannot be explained by an 

increased comorbidity burden.
• Given that all patients included in this analysis had health insurance coverage within the same vertically integrated 

healthcare system, in which barriers to care are minimized, we must identify the other factors influencing mortality risk 
among our poorest melanoma patients. 

• Some possible, modifiable behaviors that we hope to explore in the future include lack of follow up and surveillance 
allowing for close monitoring, as well as implicit bias and cultural preferences guiding treatment options offered, 
accepted, and utilized.

SYNOPSIS
• The incidence and prevalence of modifiable comorbidities is known to vary by measures 

of socioeconomic status (SES), with an excess burden appreciated among lower 
socioeconomic groups.1,2 

• It is established that both lower SES and an increased comorbidity burden result in poorer 
health outcomes.3

• We hypothesized and demonstrated that both lower SES and higher numbers of 
modifiable comorbidities, as defined by the Elixhauser Comorbidity Index (ECI), negatively 
influences all-cause mortality in patients diagnosed with melanoma.

• Specifically, we find that the survival disparity appreciated among melanoma patients of 
lower SES is persistent, albeit attenuated, even when adjusting for the presence of 
comorbidities, as defined by the ECI.

OBJECTIVE
To evaluate the influence of SES on all-cause mortality in a population of insured 
melanoma patients within Kaiser Permanente Southern California’s (KPSC) integrated 
healthcare system, while adjusting for the presence of comorbid conditions. 

METHODS

RESULTS

REFERENCES
1. Pathirana TI, Jackson CA. Socioeconomic status and multimorbidity: a systematic review and meta-analysis. Australian and New Zealand J Pub Health 42(2):186-94, 2018.
2. Tucker-Seeley RD, Li Y, Sorensen G, Subramanian SV. Lifecourse socioeconomic circumstances and multimorbidity among older adults. BMC Public Health 11(313), 2011.
3. Rosenthal A, Reddy S, Chung J, Kim C, Cooper R, Haque R. Disparities in overall survival in patients with melanoma by race/ethnicity, socioeconomic status, and healthcare 
systems. SKIN (manuscript submitted for publication November 2021).

Retrospective Cohort Study 
Design 

KPSC Cancer Registry

2010-2018

Diagnosis of Stage I-IV 
Melanoma 

7,993 Melanoma Cases 

1,243 All-Cause Deaths

Analysis by Cox 
Proportional Models

Hazard Ratios (HR) 
for the association 
between all-cause 
mortality and SES, 

adjusted for the 
presence of 
modifiable 

comorbidities (as 
determined by ECI) 

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 1 2 3 4 5+

Melanoma Diagnoses and Total 
Deaths by Number of Comorbidities 

as Defined by ECI*

Melanoma Diagnoses Total Deaths

1 1.5 2

Lowest SES

Lower-Middle
SES

Middle SES

Upper-Middle
SES

Highest SES

Hazard Ratios for All-Cause Mortality

Adjusted Model 1: HR adjusted for all sociodemographic variables (including SES), 
and not ECI 

Adjusted Model 2: HR adjusted for all sociodemographic variables (including SES) 
and ECI 

N
um

be
r 

of
 C

as
es

*ECI: Elixhauser Comorbidity Index

Number of Comorbidities by ECI