Medical science is helping millions around the globe live longer.

Average life expectancy of men increased by 5.8 years and women by 6.6 years during 1990-2013, even though some causes of death have become more lethal, says a report that will appear in medical journal Lancet this week. The report is based on data analysed by the Global Burden of Disease (GBD), a collaboration of health researchers based in US and funded by the Bill and Melinda Gates Foundation.

While rich world inhabitants lived longer thanks to falling death rates from most cancers (down 15%) and cardiovascular diseases (down 22%), their counterparts in low-income countries benefited from fewer deaths due to diarrhoea, lower respiratory tract infections and neonatal disorders.

However, mortality rose in some categories. Deaths caused by liver cancer due to Hepatitis C rose 125%, atrial fibrillation and flutter (serious disorders of cardiac rhythm) 100%, drug use disorders 63%, chronic kidney disease 37%, sickle cell disorders 29%, diabetes 9% and pancreatic cancer up 7%, the GBD study found.

Also, while deaths from AIDS have fallen sharply worldwide since its 2005 peak, the disease continues to be a mass killer in sub-Saharan Africa, where it has erased over five years from life expectancy in the last 23 years. It is still the biggest cause of premature deaths in 20 of 48 countries in sub-Saharan Africa, according to GBD.

About 500 health science researchers representing at least 300 institutions across the world are part of GBD, based out of the Institute for Health Metrics and Evaluation at the University of Washington. It had commissioned its first global disease study in 1990. The latest study estimated the number of annual deaths due to 240 different causes in 188 countries.

“The progress we are seeing against a variety of illnesses and injuries is good, even remarkable, but we can and must do even better", says Christopher Murray, professor of global health at the University of Washington, and lead author of the Lancet report.

“The huge increase in collective action and funding given to the major infectious diseases such as diarrhoea, measles, tuberculosis, HIV/AIDS, and malaria has had a real impact. However, this study shows that some major chronic diseases have been largely neglected but are rising in importance, particularly drug disorders, liver cirrhosis, diabetes, and chronic kidney disease," he added.

A regionwide analysis also found that war is a leading cause of premature death in Syria due to the ongoing conflict there. In eastern Europe, half of all premature deaths in 2013 were due to five causes: ischaemic heart disease, stroke, self-harm, cirrhosis and road injuries.

Road injuries and interpersonal violence are key contributors to premature deaths in Latin America and the Caribbean, ranking in the top five leading causes for 17 and 15 out of 29 countries in the region, respectively. Suicide was found to be a major and growing public health problem in India, with half of the word’s suicide deaths occurring in India and China alone.