Introduction
Financial interactions between physicians and pharmaceutical companies could foster healthcare innovation and improve patient care though research collaboration. However, these interaction introduce financial conflicts of interest (COIs) among physicians[1-3], potentially biasing physicians’ decision-making such as clinical practice[4-6], guideline recommendations[7-10], health policy[11], and integrity of scientific research[12,13]. Pharmaceutical companies made more than $236.0 million per year to physicians and healthcare organizations for consulting and speaking compensations in Japan[14]. The majority of these payments were directly made to individual physicians. Previous studies reported that the majority of all physicians received these personal payments for speaking and consulting services other than food and travel payments in Japan[7,8,15-32], surpassing those in other developed countries such as the United States[3,33-44], Australia[45,46], and France[47].
Among several disease areas, there is increasing attention to neurological disorders from pharmaceutical industry. The number and prevalence of patients with dementia is critically increasing in Japan. There were 4.62 million patients with dementia as of 2012[48], and it is predicted that more than 20% of all people aged 65 years and older will have dementia by 2030[49]. The healthcare spending related to Alzheimer’s disease drug were US$1.0 billion (JPY 1,073 billion) in Japan in 2018[48]. The sales of antidementia drugs including memantine (Memary from Daiichi Sankyo), donepezil (Aricept from Eisai), and galantamine (Reminyl from Takeda Pharmaceutical) was $437, $220, and $160 million in 2017, respectively. Previous research found that there were substantial financial relationships between dementia clinical guideline authors and the antidementia drug manufacturers. However, the whole picture of the financial relationships between pharmaceutical companies and all neurologists has never been investigated. Using a publicly accessible transparency database, we investigated the extents and trends of personal payments from pharmaceutical companies to all neurologists in Japan.