Limitations
This study has several important limitations. First, there may be
inaccuracies in classification of endocrinologists and reporting and
attribution of the payments in the Open Payments Database and NPPES
databases. These errors may have contributed to differences in trends
since the Open Payments system was introduced in 2013. Second, there
might be financial relationships between physicians and the healthcare
industry not covered by the Open Payments Database. For example,
information on free medication samples (15,17,18,35) and some small
payments (<$100/year) and discounts are not required to be
reported. Third, primary specialty is self-declared by each physician so
there may be misclassification. Fourth, in relation to the associated
research payments, the Open Payments Database has important limitations
in the transparency in research payment data and caution should be
exercised in interpreting the results. Associated research payments
include funding paid to affiliated institutions and are difficult to
compare to amounts paid directly to individual physicians. Further,
these research payments to teaching hospitals and other institutions
where endocrinologists served as principal investigators do not include
information about the internal allocation of research payments to
physicians, nurses, staff, and research coordinators within the
institutions. This is important as the study found that more than 99.9%
of associated research payments were assigned to teaching hospitals and
other institutions. Finally, as mentioned, the Open Payments Database
contains indirect research costs for medications and medical supplies
which were provided by the healthcare industry and were used in research
sponsored by the public sectors such as NIH. Therefore, the study
tabulations cannot discern the amount of research supported by the
healthcare industry that was provided to the NIH as industry support for
studies in which the named endocrinologists participated.