SKIN
January 2022 Volume 6 Issue 1
(c) 2022 THE AUTHORS. Published by the National Society for Cutaneous Medicine. 44
RESEARCH LETTER
Disparities in Overall Survival in Patients with Melanoma by
Race/Ethnicity, Socioeconomic Status, and Healthcare Systems
Amanda Rosenthal, MD1, Shivani Reddy, MD2, Joanie Chung, MPH3, Christina Kim, MD1,
Robert Cooper, MD4, Reina Haque, PhD3,5
1 Department of Dermatology, Kaiser Permanente Los Angeles Medical Center, Los Angeles, CA
2 California Skin Institute, Mountain View, CA
3 Department of Research & Evaluation, Kaiser Permanente Southern California; Kaiser Permanente Los Angeles
Medical Center, Los Angeles, CA
4 Department of Pediatric Hematology/Oncology, Southern California Permanente Medical Group, Kaiser
Permanente Los Angeles Medical Center, Los Angeles, CA
5 Department of Health Systems Science, Kaiser Permanente Bernard J. Tyson School of Medicine, Los Angeles,
CA
Insurance status, a proxy for access to care,
is an established correlate of cancer
outcomes. Prior work in the field of
healthcare disparities among melanoma
patients, however, has included a mix of
patients both with and without health
insurance, making it difficult to disentangle
the effects of various other
sociodemographic factors.1-5 In order to
mitigate disparities and improve outcomes,
we sought to independently examine the
effects of these intertwined
sociodemographic variables on all-cause
mortality within an insured population of
melanoma patients. Further, we aimed to
evaluate the effects of health insurance
coverage type, that is, whether patients were
cared for within an integrated healthcare
system or within a traditional model of
healthcare, on all-cause mortality risk.
Our objective was to quantify the effect of
race/ethnicity, socioeconomic status (SES)
and healthcare system on overall mortality
within an insured population of patients
diagnosed with melanoma in Southern
California from 2009 to 2014, and followed
through 2017. Healthcare system was
classified as those within Kaiser Permanente
Southern California’s (KPSC) network, a
vertically integrated healthcare system, and
insured patients outside of KPSC’s network
with other private insurance (OPI).
Using a retrospective cohort study design
with data from the California Cancer Registry,
we identified 14,614 adults diagnosed with
melanoma (Stage 0-IV). The dataset
included SES information based on
geocoded data. The total number of deaths
was 2,456 (16.8%) over a maximum follow up
of 8 years. We examined person-year (PY)
mortality rates and conducted Cox
proportional hazard models, adjusted for age,
sex, year of diagnosis, stage at diagnosis,
race/ethnicity, SES, county of residence, and
primary and adjuvant therapy.
SKIN
January 2022 Volume 6 Issue 1
(c) 2022 THE AUTHORS. Published by the National Society for Cutaneous Medicine. 45
Table 1. Demographic Characteristics of Patients Diagnosed with Melanoma between 2009-2014 in Southern
California by Health Care System
KPSC OPI Overall
N (%) N (%) N (%)
Total 4701 (100%) 9913 (100%) 14614 (100%)
Age at time of melanoma diagnosis
20-39 years 461 (9.8%) 1033 (10.4%) 1494 (10.2%)
40-64 years 2235 (47.5%) 4711 (47.5%) 6946 (47.5%)
65+ years 2005 (42.7%) 4169 (42.1%) 6174 (42.2%)
Sex
Female 1942 (41.3%) 4061 (41%) 6003 (41.1%)
Male 2759 (58.7%) 5850 (59%) 8609 (58.9%)
Socioeconomic status (SES)
Lowest SES 361 (7.7%) 510 (5.1%) 871 (6%)
Lower-Middle SES 662 (14.1%) 1077 (10.9%) 1739 (11.9%)
Middle SES 1033 (22%) 1736 (17.5%) 2769 (18.9%)
Upper-Middle SES 1389 (29.5%) 2556 (25.8%) 3945 (27%)
Highest SES 1256 (26.7%) 4034 (40.7%) 5290 (36.2%)
Race/Ethnicity
Non-Hispanic White 3904 (83%) 8721 (88%) 12625 (86.4%)
Hispanic 521 (11.1%) 629 (6.3%) 1150 (7.9%)
Non-Hispanic Black 134 (2.9%) 89 (0.9%) 223 (1.5%)
Asian/Pacific Islander 80 (1.7%) 142 (1.4%) 222 (1.5%)
American Indian 10 (0.2%) 17 (0.2%) 27 (0.2%)
Other/Unknown 52 (1.1%) 315 (3.2%) 367 (2.5%)
County of Residence
Imperial 1 (0%) 27 (0.3%) 28 (0.2%)
Los Angeles 1848 (39.3%) 3573 (36%) 5421 (37.1%)
Orange 764 (16.3%) 2481 (25%) 3245 (22.2%)
Riverside 546 (11.6%) 1080 (10.9%) 1626 (11.1%)
San Bernardino 386 (8.2%) 715 (7.2%) 1101 (7.5%)
San Diego 1156 (24.6%) 2037 (20.5%) 3193 (21.8%)
Stage at diagnosis
I 3311 (70.4%) 6123 (61.8%) 9434 (64.5%)
II 529 (11.2%) 1383 (13.9%) 1912 (13.1%)
III 255 (5.4%) 837 (8.4%) 1092 (7.5%%)
IV 164 (3.5%) 432 (4.4%) 596 (4.1%)
Unknown 442 (9.4%) 1138 (11.5%) 1580 (10.8%)
KPSC, Kaiser Permanente Southern California; OPI, other private insurance.
SKIN
January 2022 Volume 6 Issue 1
(c) 2022 THE AUTHORS. Published by the National Society for Cutaneous Medicine. 46
Table 2. Overall Mortality Rates per 1000 Person-Years and Overall Mortality per Multivariate Adjusted Hazard
Ratios by Health Care System Stratified by Age at Time of Melanoma Diagnosis, and Race/Ethnicity,* SES, and
Stage of Melanoma
KPSC OPI TOTAL
#
deaths
Rate per
1000 PY
(95% CI)
HR (95% CI) #
deaths
Rate per
1000 PY
(95% CI)
HR (95% CI) #
deaths
Rate per
1000 PY
(95% CI)
HR (95% CI)
Total 729 45.9
(42.7,49.4)
N/A 1727 53.6
(51.1,56.1)
N/A 2456 51.0
(49,53.1)
N/A
Age at time
of melanoma
diagnosis
20-39 years 17 10.1
(5.9,16.1)
1 (ref) 55 15
(11.3,19.5)
1 (ref) 72 13.4
(10.5,16.9)
1 (ref)
40-64 years 157 19.8
(16.8,23.2)
1.75
(1.06,2.90)
386 24.4
(22,26.9)
1.61
(1.21,2.14)
543 22.8
(21,24.9)
1.63
(1.28,2.09)
65+ years 555 88.6
(81.4,96.3)
7.65
(4.67,12.51)
1286 101.1
(95.6,106.8)
6.21
(4.68,8.25)
1841 97.0
(92.6,101.5)
6.65
(5.21,8.49)
Race/Ethnicit
y
Non-Hispanic
White
626 46.9
(43.3,50.7)
1 (ref) 1558 54.6
(51.9,57.3)
1 (ref) 2184 52.1
(50,54.4)
1 (ref)
Hispanic 64 38.2
(29.4,48.8)
0.72
(0.54,0.95)
114 63.3
(52.2,76.1)
0.79
(0.64,0.96)
178 51.2
(44,59.3)
0.76
(0.65,0.9)
Non-Hispanic
Black
25 62.1
(40.2,91.7)
0.87
(0.57,1.32)
19 66.3
(39.9,103.6)
1.00
(0.63,1.60)
44 63.9
(46.4,85.7)
0.92
(0.68,1.26)
Asian/Pacific
Islander
13 56.1
(29.9,95.9)
0.95
(0.54,1.66)
29 71.4
(47.8,102.5)
1.24
(0.85,1.80)
42 65.8
(47.4,89)
1.12
(0.82,1.53)
American
Indian
1 29.5
(0.7,164.3)
0.57
(0.08,4.08)
3 68.2
(14.1,199.4)
1.73
(0.43,6.94)
4 51.4
(14,131.5)
1.06
(0.34,3.29)
Other/Unkno
wn
4 3.5 (0.9,8.8) 0.09
(0.03,0.25)
4 3.0 (0.8,7.7) 0.083
(0.03,0.22)
Socioecono
mic status
(SES)
Lowest SES 69 57.7
(44.9,73.1)
1.47
(1.09,2.00)
137 96.4
(80.9,113.9)
1.80
(1.47,2.22)
206 78.7
(68.3,90.2)
1.70
(1.43,2.02)
Lower-Middle
SES
103 47.5
(38.8,57.6)
1.40
(1.08,1.80)
264 77 (68,86.9) 1.50
(1.28,1.76)
367 65.6
(59,72.6)
1.47
(1.29,1.68)
Middle SES 164 46.5
(39.7,54.2)
1.28
(1.03,1.60)
348 64
(57.4,71.1)
1.39
(1.21,1.61)
512 57.1
(52.3,62.3)
1.36
(1.21,1.53)
Upper-Middle
SES
210 44.3
(38.5,50.7)
1.15
(0.94,1.41)
422 50.1
(45.4,55.1)
1.19
(1.04,1.35)
632 48.0
(44.3,51.9)
1.19
(1.07,1.33)
Highest SES 183 43.1
(37.1,49.8)
1 (ref) 556 41.1
(37.8,44.7)
1 (ref) 739 41.6
(38.6,44.7)
1 (ref)
Stage at
diagnosis
I 293 24.8
(22.0,27.8)
1 (ref) 484 22.8
(20.8,25.0)
1 (ref) 777 23.5
(21.9,25.2)
1 (ref)
II 142 88.6
(74.6,104.4)
2.58
(2.10,3.16)
398 22.8
(20.8,25.0)
2.98
(2.60,3.41)
540 91.5
(83.9,99.5)
2.85
(2.55,3.19)
III 87 117.8
(94.3,145.3)
4.55
(3.54,5.84)
300 125.9
(112.0,140.9)
4.40
(3.79,5.11)
387 124.0
(111.9,136.9)
4.38
(3.86,4.97)
IV 114 460.7
(380.0,553.
5)
13.34
(10.01,17.79)
320 507.9
(453.7,566.7)
10.54
(8.79,12.64)
434 494.6
(449.1,543.4)
11.28
(9.70,13.11)
Unknown 93 64.0
(51.7,78.4)
2.01
(1.57,2.56)
225 60.2
(52.6,68.6)
2.08
(1.77,2.45)
318 61.3
(54.7,68.4)
2.04
(1.79,2.34)
KPSC, Kaiser Permanente Southern California; OPI, other private insurance. * Insufficient power to determine statistical sign ificance among
Asian/Pacific Islanders and American Indians
SKIN
January 2022 Volume 6 Issue 1
(c) 2022 THE AUTHORS. Published by the National Society for Cutaneous Medicine. 47
Table 1 shows the distribution of
demographics of the insured patients by
healthcare system. KPSC had more
minorities and those in the lowest two SES
quintiles. Table 2 provides the PY all-cause
mortality rates and multivariate adjusted
hazard ratios (HR) by healthcare system. PY
mortality rates by race/ethnicity did not yield
significant results, possibly given the small
numbers of deaths in certain populations.
Mortality rates increased by decreasing SES
quintile in the overall population. When
stratifying by healthcare system, the PY
mortality rates among those patients in KPSC
were much more similar among SES groups,
with the 95% confidence intervals (CI)
overlapping for all five SES quintiles. By
contrast, in OPI, the CIs for the lowest, lower-
middle, and middle SES groups did not
overlap with the CIs of the upper-middle and
highest SES groups. Of note, the KPSC
patients in the three lowest SES quintiles had
statistically significant decreased mortality
rates compared to their OPI counterparts.
In multivariable adjusted hazard models, we
did not observe differences in mortality risk
by race/ethnicity in either healthcare system,
when using Non-Hispanic Whites as the
reference population. We did appreciate an
increased mortality risk by decreasing SES
quintile in KPSC and OPI, when using the
highest SES quintile as the reference
population. This trend, however, was much
more apparent in the OPI group. For
example, the poorest patients in OPI had a
mortality risk 80% greater than wealthiest
patients in OPI (HR 1.80; 95% CI 1.47, 2.22),
while the poorest patients in KPSC had a
47% greater risk than the wealthiest patients
in KPSC (HR 1.47; 95% CI 1.09, 2.00).
In summary, our results suggest that
disparities in overall mortality persist, even in
a cohort with health insurance coverage, and
that lower SES is an important driver of this
disparity. We also underscore the survival
advantages for those vulnerable populations
cared for within an integrated healthcare
network, such as KPSC.
Conflict of Interest Disclosures: None
Funding: This study was funded by Kaiser
Permanente Southern California’s Regional
Research Committee.
Corresponding Author:
Amanda Rosenthal, MD
Department of Dermatology
Kaiser Permanente Los Angeles Medical Center
1515 N Vermont Ave
Los Angeles, CA 90027
Amanda.x.Rosenthal@kp.org
References:
1. Dawes SM, Tsai S, Gittleman H, Barnholtz-Sloan
JS, Bordeaux JS. Racial disparities in melanoma
survival. Journal of the American Academy of
Dermatology. 2016;75(5):983-91.
2. Collins KK, Fields RC, Baptiste D, Liu Y, Moley J,
Jeffe DB. Racial differences in survival after
surgical treatment for melanoma. Annals of
surgical oncology. 2011;18(10):2925-36.
3. Wu X-C, Eide MJ, King J, Saraiya M, Huang Y,
Wiggins C, et al. Racial and ethnic variations in
incidence and survival of cutaneous melanoma in
the United States, 1999-2006. Journal of the
American Academy of Dermatology.
2011;65(5):S26. e1-S. e13.
4. Zell JA, Cinar P, Mobasher M, Ziogas A,
Meyskens Jr FL, Anton-Culver H. Survival for
patients with invasive cutaneous melanoma
among ethnic groups: the effects of
socioeconomic status and treatment. Journal of
clinical oncology: official journal of the American
Society of Clinical Oncology. 2008;26(1):66-675.
5. Cormier JN, Xing Y, Ding M, Lee JE, Mansfield
PF, Gershenwald JE, et al. Ethnic differences
among patients with cutaneous melanoma.
Archives of internal medicine. 2006;166(17):1907-
14.
mailto:Amanda.x.Rosenthal@kp.org