Results
Of the 6,107 board-certified neurologists, 3,615 (59.2%) received
personal payments from the pharmaceutical companies over the five years
between 2016 and 2020 (Table 1). The total amounts of personal payments
were in $45,726,920 entailing 37,337 payments. For neurologists who
received at least one payment, the median amount per neurologist was
$2,423 (interquartile range [IQR]: $765–$9,076), in contrast to
a mean of $12,649 (standard deviation [SD]: $35,012) over the
five-year span. The Gini index, used to measure payment distribution
among neurologists, was 0.871, suggesting that a small proportion of
neurologists received the majority of personal payments over the five
years. Specifically, the top 1% (61 neurologists), 5% (305
neurologists), and 10% (611 neurologists) of these neurologists
received 30.3%, 52.8%, and 78.8% of all personal payments,
respectively. Of the three payment categories, lecturing payments
occupied 84.4% of overall payments to the neurologists ($38,612,931).
Additionally, 58.1% of all neurologists received at least one lecturing
payments from the pharmaceutical companies between 2016 and 2020. Mean
value per payment was $1,243 for lecturing payments, $1,236 for
consulting payments, and $915 for writing payments.
Of 78 pharmaceutical companies making payments to the neurologists,
Daichi Sankyo made the largest amounts of personal payments totaling
$6.3 million, followed by Eisai ($5.0 million), Takeda Pharmaceutical
($4.5 million), Otsuka Pharmaceutical ($3.8 million), and Kyowa Kirin
($3.2 million). The top 5 and 10 companies with the largest payment
amounts were responsible for 50.2% ($22.9 million) and 74.5% ($34.1
million) of all payments over the five years.
The total annual amounts of personal payments to neurologists showed an
increasing trend from $8.8 million in 2016 to $10.0 million in 2019
(Table 2), but decreased to $8.1 million in 2020. There was a similar
trend in the number of payments over the five years. Of all
neurologists, 33.0% to 36.8% received at least one personal payment
each year. The number of neurologists receiving payments significantly
increased by 1.5% (95% confidence interval [95% CI]:
0.4%–2.6%, p<0.001) each year from 2179 in 2016 to 2292 in
2019. Among neurologists receiving payments, median annual payments per
neurologist were from $1,077 to $1,356 in monetary value and 2.0 in
the number of payments. Payments per neurologist annually increased by
3.2% (95% CI: 0.9%–5.5%, p=0.006) in monetary value and by 3.5%
(95% CI: 2.4%–4.7%, p<0.001) in the number of payments
between 2016 and 2019. Contrarily, there was significant decreases of
14.3% (95% CI: -16.4% to -10.1%, p<0.001) in the number of
neurologists receiving payments and 21.1% (95% CI: -25.3% to -16.7%,
p<0.001) in payments per neurologist in 2020 when compared to
those in the previous years.