Life Expectancy: Discrepancies, Outcomes, and Future Directions

Life Expectancy: Discrepancies, Outcomes, and Future Directions

By Ava Torjani

A recent study demonstrated a significant improvement in life expectancy among the least-expected countries, including Niger, Nicaragua, Ethiopia, Gambia, Nepal, and Peru. These are low-income countries with relatively low access to and quality of healthcare. On the other hand, people in several high-income countries, including parts of the US, Greenland, and Russia are not living as long as expected. This article will explore the data presented by several studies, as well as the proposed reasons behind their findings.

Life expectancy refers to the average number of years that an individual is expected to live at a particular age if the same mortality conditions persisted throughout the rest of his or her life. The most prevalent predictors of higher life expectancy include greater wealth, fewer number of children, and a higher level of education. Overall, life expectancy has improved across the world, increasing from 65.3 years in 1990 to 71.5 years in 2013. Additionally, life expectancy at birth for females and males has increased by 6.6 and 5.8 years, respectively. These improvements are primarily due to more effective and accessible treatments against cancers and cardiovascular diseases in high-income countries, which extend life expectancy at age 65 and older, and against rotavirus-based diarrhea, neonatal disorders, and lower respiratory infections in low-income countries, which increases life expectancy at birth. Despite these improvements, life expectancy is generally shorter in low-income than high-income countries due to discrepancies in resources, income, and access to healthcare.

BBC’s illustration of population pyramids organized by a country’s socioeconomic status. The left pyramid describes low-income countries wherein birth and mortality rates are high. The right pyramid describes high-income countries where birth and mortality rates are low. Image found on

Interestingly, the greatest improvement in life expectancy was seen among developing countries to an unprecedented extent. For example, Niger and Nicaragua demonstrated an outstanding 7.8-year increase in lifespan. Christopher Murray, a health economist at University of Washington, suggests that this may be thanks to greater access to healthcare in rural and remote areas, more comprehensive child care, and effective treatments against HIV and AIDS. However, further research on public policies and healthcare practice needs to be conducted to establish concrete reasons for this improvement in life expectancy. Not only will this provide insight into effective measures to prevent greater death tolls, but it could also serve as a model for health improvement among other low- and middle-income countries who currently struggle to establish effective healthcare strategies.

Expected and observed life expectancy at birth for low-income and low-middle/middle income countries. Image found on

On the other hand, high-income countries, including Greenland and Russia, and American states such as Mississippi have shown a far less promising increase in life expectancy. In fact, America saw its first decline in life expectancy since 1993, dropping from 78.9 years in 2014, to 78.8 in 2015, and only slightly increasing to 79 years in 2017 for both sexes combined. Two health economists at Princeton, Anne Case and Angus Deaton, believed that this was a result of diseases of despair, which encompasses suicide, drug overdose, and addiction, as well as an increase incidences of obesity and diabetes—issues that are ‘affordable’ to those living in high-income countries.

Additionally, the lack of substantial increase for life expectancy may be due to economic inequality, insufficient attention to issues in early stages of child development, and a discrepancies in healthcare access and quality. Alternatively, the increased life expectancy over the decades may have induced the cumulative effect of diseases that burden the aging population, including Alzheimer’s disease which saw an increase from 25.4 to 29.4 deaths per 100,000 people. Nevertheless, these issues highlight the need to develop accessible and effective care for diseases beyond physiological pathology, as well as to adjust research focus to accommodate the aging population.

Overall, these studies demonstrate an optimistic outlook on life expectancy worldwide thanks to advances in medical research, public health policy, and healthcare. However, it is important to consider ways to improve life expectancy at 65 years in high-income countries, and life expectancy at birth in low-income countries. Therefore, it is beneficial to address factors that contribute to non-infectious causes of death within high-income countries, while concurrently examining reasons behind discrepancies in life expectancy at birth in low-income countries.

For example, in high-income countries, understanding the effects of stress and other socioeconomic factors on physical and psychological health will prove critical to developing interventions to prevent their deleterious impacts. On the other hand, in low-income countries, many people still die from treatable diseases such as diarrhea and respiratory infections. Hence, greater research and support should be offered to catalyze the process of discovering, providing, and improving the efficacy and effectiveness of treatments for these diseases. Taking into account all these matters, it is evident that although we have succeeded in improving the average lifespan of an individual, there is still a long way to go.


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