Limitations
Limitations of this study include those inherent to the SEER database.
Data on patients’ overall health status and comorbidity burden were
unavailable, which may impact surgical candidacy and the decision to
pursue definitive treatment. We were not able to control for potentially
confounding behavioral risk factors (e.g. smoking and alcohol
consumption) and socioeconomic variables (e.g. education level, median
household income, and metropolitan status), which may be able to explain
at least some of the observed differences amongst treatment type across
insurance categories, especially pre-ACA. Finally, this study is also
subject to limitations inherent to the use of any large databases, such
as the potential for misclassification and coding errors. In most
states, individuals who are diagnosed with cancer can qualify for
Medicaid, with the eligibility date assigned as the date of diagnosis.
Thus, patients can move from the uninsured group to the Medicaid-insured
group, confounding the classification of insurance status. In addition,
it is also possible that individuals’ insurance coverage may change over
the course of their treatment, which may not be captured by SEER.