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Supplemental Materials
It is difficult to determine a single underlying COD in HIV-infected people because of their
multiple comorbid conditions. For example, a death in an HIV-infected person with NHL might be
inaccurately attributed to HIV/AIDS when NHL is the underlying COD or vice versa. Because
NHL is an AIDS-defining condition, clinicians may code a death from NHL as caused by underlying
HIV/AIDS. Furthermore, clinicians may miscode a death as due to another cancer when the
patient’s only known cancer is NHL (1).
We assessed this issue by comparing estimates of NHL-specific survival (using varying
definitions of a cancer-specific death) with estimates of relative survival. Relative survival is
calculated as the ratio of overall survival in people with a cancer to expected survival based on a life
table for the source population. Since relative survival does not use any specific CODs, it can be
treated as a gold standard to assess mortality due to a cancer, Thus, cancer-specific survival should
match relative survival if cancer-specific deaths are accurately captured by the selected CODs and
there are no confounding factors influencing mortality in cancer patients (1).
For this analysis, we used data from the HIV/AIDS Cancer Match (HACM) Study, a linkage of
population-based HIV and cancer registries in the United States (http://hivmatch.cancer.gov/) (2).
Six HACM sites (Colorado, Connecticut, Georgia, Michigan, New Jersey, and Texas) provided data
on CODs among HIV-infected NHL cases and on overall mortality in the HIV population for
1996-2012. We calculated five-year relative survival among HIV-infected NHL cases using a life
table based on the overall HIV population, and compared this to estimates of NHL-specific
survival based on varying CODs specified by International Classification of Diseases (ICD) codes
(version 10) (1): 1) any hematologic malignancy, 2) any hematologic malignancy plus any other
cancer (if NHL was the case’s only diagnosed cancer), 3) any hematologic cancer plus HIV, 4) any
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hematologic cancer plus “AIDS & Cancer” (here, AIDS & Cancer is a special category of deaths
captured using a specific set of ICD codes), 5) any hematologic cancer plus (AIDS & Cancer) plus
HIV, and finally, 6) using the SEER special COD variable which encompasses all of these
categories plus some related neoplastic conditions (1). Supplemental Table 1 displays the ICD codes
used to capture these CODs.
The results are shown in Supplemental Table 2. Five-year relative survival was 21%. In
comparison, NHL-specific survival among HIV-infected NHL cases was much too high when we
counted only hematologic cancer deaths (71%). However, when we used the SEER special COD
variable, five-year cancer-specific survival was 22%, matching relative survival closely. Thus, this
analysis demonstrates that a large fraction of deaths among HIV-infected people with NHL are
miscoded to HIV/AIDS when they should be counted as NHL-specific deaths. To accurately
capture all deaths among HIV-infected NHL cases that are due to NHL, one must utilize the SEER
special COD variable.
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Supplemental Table 1: ICD-10 Codes for SEER Special Cause of Death Variable for NHL.
Cause of death for individuals diagnosed with only NHL
(Tumor sequence 0)
Primary
Diagnosis
Cancer of same
diagnosis site
Cancer of same
body system
Any other cancer†
AIDS &
cancer
HIV alone
NHL
C77, C81-C96,
D360, D470
D361-D369,
D471-D479
C000-C769,C780C809,C970D359,D370D469,D480-D489
B210-219
B20, B22B24
Causes of death for individuals diagnosed with NHL and subsequent cancers
(Tumor sequence 1)
Primary
Diagnosis
Cancer of same
1st diagnosis
site
Cancer of same
body system
Cancer of
unknown site
AIDS &
cancer
HIV alone
NHL
C77, C81-C96,
D360, D470
D361-D369,
D471-D479
C798,C800C809,C970C979,D489
B210-219
B20, B22B24
Source: SEER cause-specific death classification variable: http://seer.cancer.gov/causespecific/. Corresponding ICD-9 and ICD-8
codes for NHL COD are also available from this URL link.
† This category includes any malignant cancer deaths other than NHL.
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Supplemental Table 2: Five-Year Cancer-Specific Survival and Relative Survival Estimates.
5-Year Survival
Estimate
Method
Cancer-specific survival, according to specified causes of death
Any hematologic cancer
71%
Any hematologic + any other cancersa
69%
Any hematologic cancer + HIV
44%
Any hematologic cancer + (AIDS & Cancerb)
42%
Any hematologic cancer + (AIDS & Cancerb)+ HIV
26%
SEER special CODc
22%
Relative survival
21%
a: “Other cancers” are used for the subset of cases when tumor sequence number = 0.
b: AIDS & Cancer is a special category of CODs (codes B210-B219) captured separately from other cancer CODs.
c: SEER special COD variable includes deaths from any hematologic malignancy, another cancer (if the person had NHL as the only
incident cancer), related neoplastic conditions, or HIV/AIDS.
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References
1.
Howlader N, Ries LAG, Mariotto AB, Reichman ME, Ruhl J, Cronin KA. Improved
Estimates of Cancer-Specific Survival Rates From Population-Based Data. Journal of the National
Cancer Institute. 2010;102:1584-98.
2.
Engels EA, Pfeiffer RM, Goedert JJ, Virgo P, McNeel TS, Scoppa SM, et al. Trends in
cancer risk among people with AIDS in the United States 1980–2002. AIDS. 2006;20:1645-54.
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