Singaporeans will have the third-longest lifespans globally in 2040, according to a study by the University of Washington's Institute for Health Metrics and Evaluation (IHME) published on Wednesday (Oct 17) in medical journal The Lancet.

The average life expectancy in Singapore will be 85.4 years.

The 2040 forecast places the city-state third out of 195 countries, with Spain coming in first with an expected average lifespan of 85.8 years and Japan in second with 85.7 years.

Singapore's average life expectancy in 2016 was 83.3 years, which also ranked third in the world out of 195 countries.

"Singapore's ranking as third in the world illustrates the effectiveness of its current health systems at addressing key health drivers," said an IHME statement on the study.

It added that the top six health drivers that explain most of the future trajectory for premature mortality are: High blood pressure, high body mass index, high blood sugar, tobacco use, alcohol use and air pollution.

The leading causes of death in Singapore in 2040 are expected to be: Lower respiratory infections, ischemic heart disease, Alzheimer's disease, lung cancer, chronic kidney disease, liver cancer, colon and rectum cancer, stroke, hypertensive heart disease and chronic obstructive pulmonary diseases.

In 2016, the top 10 causes were: Ischemic heart disease, lower respiratory infections, lung cancer, Alzheimer's disease, stroke, colon and rectum cancer, suicide, chronic kidney disease, liver cancer and breast cancer.