Men in managerial positions or professional occupations in Japan have a higher mortality rate than their counterparts in Europe, according to a scientific study published in late May.

The study was conducted on men who were aged between 35 and 64 during the period from 1990 to 2015 in Japan, South Korea and eight European countries including Denmark and Switzerland, by a team of researchers from the University of Tokyo and European institutes.

The findings, reported in the Journal of Epidemiology & Community Health, said that the mortality rate of “upper nonmanual workers” increased in Japan in the second half of the 1990s following the collapse of the asset-inflated bubble economy. The trend was possibly due to changes in their social and work environments — such as having to work in dual roles, as a manager and a worker, following restructuring, for example, according to the report.

The economic crisis saw managers and the professional class lose decision-making discretion, suffering greater psychological stress and an increasing workload, while overtime hours for most other occupations decreased, the study said.

Cancer made the largest contribution to rising mortality in this occupational category, with suicide also factoring heavily.

The article also referred to previous studies that suggested heavy job demands and long working hours made it difficult for such workers to make time for health checkups.

In 2015, 375 of every 100,000 people in the managerial and professional classes died — almost 1.4 times the figures seen for lower nonmanual workers such as clerical and service employees.

While the mortality rate among managers and professionals has been declining since the 2000s, this could be set to reverse once more, as a recent labor reform law in Japan exempts certain categories of skilled professionals with high wages, such as consultants and financial traders, from the legal cap otherwise applied to working hours.

Yasuki Kobayashi, professor of public health at the University of Tokyo, noted that managers who are supposed to be able to regulate their own schedules tend to drive themselves to work long hours.

“It is necessary to continue labor reforms and to be equipped with statistical analyses to understand the situations of those with bad health,” he said.

In South Korea, the mortality rate among managers and professionals rose in the late 2000s, following the 2008 global financial crisis triggered by the collapse of the U.S. investment bank Lehman Brothers Holdings Inc. As in Japan, cancer made the largest contribution.

In Europe, the trend was reversed, with manual workers consistently having higher mortality rates than upper nonmanual workers.