A new study by the Lancet has found that global life expectancy increased by 6.2 years between 1990 and 2021, driven by reductions in deaths from various diseases such as diarrhea, lower respiratory infections, stroke, and ischemic heart disease. These improvements led to annual reductions in deaths from all causes ranging from 0.9% to 2.4% during this time period. However, the study also revealed significant setbacks caused by the Covid-19 pandemic, which resulted in a net reduction in life expectancy of 1.6 years between 2019 and 2021.
The leading causes of death worldwide remained consistent from 1990 to 2019, with diseases like ischemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections topping the list. The pandemic had a major impact on global mortality rates, with Covid-19 becoming the second-leading cause of death, leading to a shift in the rankings that had not been seen for decades. The age-standardized mortality rate for ischemic heart disease dropped by 31.5% between 1990 and 2021, while Covid-19 had an age-standardized mortality rate of 94.0 in 2021.
Changes in life expectancy varied significantly by region, with the super region consisting of Southeast Asia, East Asia, and Oceania seeing the greatest net gain in life expectancy, rising by 8.3 years from 1990 to 2021. This was attributed to reductions in mortality rates from chronic respiratory diseases, stroke, lower respiratory infections, and cancer. Control of mortality due to enteric diseases, including diarrhea and typhoid, also contributed to improvements in life expectancy globally, estimated to contribute an overall increase of 1.1 years.
The study highlighted the impact of the Covid-19 pandemic on different regions, with Latin America and the Caribbean experiencing the largest decline in life expectancy due to Covid-19, resulting in a 3.6-year reduction. In contrast, the super region of South Asia had the second-highest increase in life expectancy among super regions, with 7.8 years, while Eastern sub-Saharan Africa had the highest increase in life expectancy of any local region, with 10.7 years.
The authors of the study emphasized the need to address the dual challenges of preventing deaths from various diseases while also managing the impact of the Covid-19 pandemic. Dr. Liane Ong of the Institute for Health Metrics and Evaluations pointed out the significant achievements in preventing deaths from diseases like diarrhea and stroke, but also highlighted the setbacks caused by the pandemic. The study also noted that Covid-19 may have had indirect effects on mortality rates, with physical distancing measures affecting mortality for other diseases, and deferred care-seeking leading to pandemic-related deaths not directly attributable to Covid-19. This research provides valuable insights into the global trends in life expectancy and the impact of the pandemic on mortality rates.
